Note: Descriptions are shown in the official language in which they were submitted.
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MET:~IOD AND SYSTEM FOR
~U~I:~ATICALLY Sl~:RING ~I~ONG P~Oh' CROPS
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BACXGRQUND
~he present invention relates to automatic methods
20 and systems for ste~ring along row crops and pseventing
accidents during automatic . teering, and more
particularly to autom~tic methods for steering among row
crops adapted for use in settings where thicknesses of
plants vary .
25 Back 3round A~
Automatic steering methods among row ~rops are
commonly used in harves~ing where thicknesses of plants
ehange within a row, and they may be used elsewhere as
well. In various applications, a hum,an operator may lack
30 the skills needed to steer eficierltly ~n agricultural
machine~ e.g., a harvester. In these and other
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applications, a self-sufficient aut~matic stee~in~ method
is indicated. However, if the h~man operator relies on
automatic steering, through inat~entiveness or
preoccupation with other tasks the operator may miss gaps
5 which occur in rows and allow the machine to overr~n a
~ row end, risking serious accident. ~ence, a
:~ self-s~lfficient steering method must also be safe.
Conventional methods sense a deviation from 2
desired, straight ahead cou~se and then correct t~.e
deviation 50 as to steer on a straight courseO Sevcral
patents show this approach, U.S. 4,367,802 (Stiff et
al.), ~.S~ 4,366,756 (Brum~, U.S. 3,797,602 (Sumida),
U.5. 3,550;790 (N~ble), and U.S. 3,402,784 (Roberson),
. each ~sing a furrow plouyhed in the ground for guidance.
U.S. 4~345,659 (Arnold) shows a v~riation for sod
harvesting. Sometimes it is impractical to follo~ a
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furrow in the ground. Accordingly, methods emplo~- dual
resilient sensin~ arms which press against ~he risht and
left side ~f a row of crops and then generate on-off
correction signals, as ~.S~ 4,528~804 (~illiams) and a
companion patent, U.S. 4,505,094 ~Demorest~ disclose.
,
The object of al.l of these metbods essentially is to
steer straight ahead. To do this, the methods re~uire
some sort of feedback which measures a corrective motion
so that the tending machine attains a straight ahead
course. ~or instance, this feedback appears in me~hods
employing resilient crop-sensing arms. It takes 2 form
there of a simple expedient o~ halting turning once the
arm loses contact with the c~ops.
~' 30 As the thickness of the plants changes, sensing
members wh~ch press against the left and right siaes of
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the plants may generate contradictory signals.
Consequently, a hiat~s in sensing may occ~r t and
so~etimes a human oper~tor must monitor steering and
freguently override an a~tomatic system. Hence,
variation in plant thicknesses presents a special kind of
problem.
~ .S. 4,304,316 (Lang) addresses this problem. It
shows left and right resilient arms that generate
hydraulic signals Xl and X2. These signals indicate a
degree of steering error, thus they are quantitative. An
ar~, 40 (or.in a separate embodiment~ a lever 86) within a
: hydraulic chamber produces an output hydraulic signal
which i~ the absolute value of a difference Xl _ X2
between the signals. This process compensates for
variations in plant thickness. However; this approach
entails some new difficulties. This method includes a
step, namely, correlating a corrective motion to a
~uantity of steering error. Without this step, the
machine would not steer on a straight ahead course~ To
execute this step, this method requires hydraulic
equipment, ho es and a valve body. Also, the f`act ~hat
this method is self-suffieient and that a human operator
is disengaged from driving the machine, heightens a need
for protection against possible overrunning of row ends.
A type of gap protection is known in grass and grain
crop steering ~ethods. ~.S~ 3,~52,828 (Stampfer et al.)
shows left and right detectors 86 and 86', which sense
the presence or absence of grain. At the end of a field
they both generate signals which tell the harvester to
h21t. Ho~ever, this process reguires a field crop. Row
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crop steering methods still lack a sati~factory W2y to
pro~ect against overrunning of gaps and row ends.
Signals which an automatic steering system ger.erates
when contacting plants in a row, indicate the presence of
~ 5 the row. A gap in these signals can warn of a gap in the
: ro~. However, because of the focus of conventional
me~hod5 on steering straight ahead, wherein an objective
is to minimize row contact, ~he use of contact signals
for gap detection is often forgotten. Additionally,
hydraulios, or other means of guantitatively correlating
corrections with errors~ in certain circumstances can
co_plicate the automatic steering process. The state of
~ the art still insists on steering straight ahead only.
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S 11MMA RY OF THE I NVENT I O~'
. Accordingly, it is an object of the present
invention to steer a row crop tending machine
5 self-sufficiently among crops of varying thicknesses.
: Another object of the invention is to exploit
~ contact signals which a steering system generates thus
.: preventing accidents due to ~he overrunning of gaps in
rows and row ends.
Another object of the invention is to provide
simpler methods and systems ~or monitor ing a course and
: crop thicknesses, thereby reducing steps, the number of
~` components, and cost.
Another object of the invention is to steer
sufficiently close to row crops ~or a variety ~f
agricultural applications.
The present invention accomplishes these and other
. objects which are apparent from consideration of the
detailed description and claims.
In an e~bodiment of the invention, a machine used in
agricultural operation, such as harvesting, has an
~utomatic ~teering means and an automatic machine
shutdown means. As used herein, a direction ~forward~
!i I means the usual direction of travel of the chassis a
direction ~outward~ means away from the row of crops.
The automatic steering means of ~he invention
includes the ~ollowing functional elements: a turning
; means, such as a steerable, ground-engaging wheel; a
monitor ing assembly; a pivoting control means; and a
pivotposition monitoring means. The row location
assembly determines the location of first and second
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sides of the row with respect to the machineO ~he
monitoring assembly, which co~municates with the row
locating assembly, monitors those locations and
determines the location of a row axis or centerline with
respect to the machine regardless of variations in the
thicknesses of plants within the row. The turning means
has first and second pi~ot limits both of which are
angularly displaced from an alignment axis (which
represents the direction in which the machine steers when
moving straight ahead). The pivoting means moves the
turning means angularly to either the f irst pivot limit
or the second pivot limit. The pivoting control means
directs the pivoting means to move toward the first pivot
limit, to cease pivoting, or to move to the second pivot
limit. Conditions where an alignment location fixed on
the machine is off to first and second sides of the row
centerline, respectively, are called ~firs~ and second
turn conditionsn. Assuming that the first ~urn condition
exists, the monitoring assembly imparts a signal to the
pivo~ing control means, which starts the turning means
(steerable wheel) moving toward its first pivot limit~
When the turning means attains the irst pivot limit, the
pivot position monitor which i5 connected to the turning
means imparts a signal to the pivoting con~rol means
which ceases pivoting of the turning means. The ~urning
means is now in the first pivs~ limit snd the machine
steers itself back toward the row centerline.
Assuming that the second turn condition exists, the
monitoring assembly imparts a signal to the pivoting
control means which causes the turning means to ~.ove
toward the second pivot limit. When the turning means
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reaches its second pivot limit, the turning means
monitoring means imparts a ~ignal to the pivoting control
means which ceases pivoting of the turning means. The
turning means is now in its second pivo~ limit and the
machine steers back toward the row centerline.
Assuming in each case des~ribed ~hat ~he row axis
centerli"e is approximately straight, the described
process repeats in cycles whereby the machine describes a
i path oscillating between the machine's first and second
sides. ~
In this embodiment, the row locating assembly
includes first and second, longi~udinally extending,
generally parallel, locating members. Each locating
member has a forward portion, a middle portion, and a
15 rearward portionr the forward portion curving forwardly
and outwardly, and 'che middle portion aligning generally
parallel to the row. The ~irst locating member presses
,iagainst a first side of the row and the second locating
member presses against a second side. Re ilient means
~20 connected to the loca~ing members provides the pressing
., force,
Also, the monitoring assembly comprises first and
second substantially parallel monitoriny bars. These
monitoring bars mutually define a monitoring pathway.
The first monitoring bar is extendable in a first
monitoring direction and retractable in a second, opposed
moni~oring direction; the second monitoring bar is
extendable in the second monitoring direction and
retractable in the first monitoring directionO ~ linkage
~eans, comprising arms and rods~ connects the first and
, second locating members to the first and second
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r.onitoring bars. The linkage means is arranged in a
~.anner such that a displacement of the first monitoring
bar in the first direction corresponds to an outward
displacement of the first locating member, and a
5 displacement of the second monitoring bar in the second
direc~ion corresponds to an outward displacement of the
second locating member. A monitoring wheel which engages
both of the monitoring bars is posi~ioned be~ween the
.onitoring bars. Preferably, each of the monitoring bars
10 is a toothed rack, and the monitoring wheel is a toothed
gear which engages the racks.
A technique as follows monitors the location of the
row centerline in relation to the machine. In the
monitoEing pathway in a housing, at ~eparate loca~ions,
s 15 are placed first and second monitoring switches. The
monitoring wheel connects pivotally to a movable housing.
The monitoring wheel and ~he movable housing are moun~ed
in a channel means in a fixed housing in which they move
back and forth together~ Then, they move back and for~h
20 in response to the extension and retraction of the first
and second monitoring bars. Due to ~he monitoring
wheel~s engagement with the first and second monitoring
I bars~ the monitoring wheel moves in ~he first monitoriny
s direction in the monitoring pathway when the first turn
~ 25 condition exists. It moves in the second monitoring
direction in the monitoring pathway, when the second turn
condition exists. Preferably, the positions of the t~o
monitoring switches are arranged so that the followin~
occurs: the swi~ch activating member activates the first
30 and second monitoring switches when the first and second
~rn conditions exist, respectively. It is also possible
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to position the s~itches in a m3nner t~ delay their
ac~ivati~n beyond the descri~ed activation~ alth~ugh this
reduces the invention's sensitivity to the first and
r econd turn conditions.
When in the first and s~cond pivot limits, the
steerable wheel turns the machine toward the machine 's
first and ~econd sides, respectively, (the machinels
first side corresponding to the first locating me~ber;
the machine's second side opposing the first side). The
10 pivot limit monitoring means monitors the steerable
~heel 's att.ainment of the fiIst .and second pivot limits
and, once a pivot limit is attained, keeps the steerable
~heel in that pivot limit until there is change in the
t~rn condition. The pivot limit monitoring means
lS includes the following components. The pivoting n~eans
connects to an arc-shaped-~itch activa~or which rotates
~hrough an angle that includes the first and second pivot
limits. The arc-shaped switch activatc~r describes a path
as it pivots. First and second limit switches are
20 positioned adjacent to th~t path in a manner such that
the arc-shaped switch activator activates, respectively,
the first and second limit ~witches when the steerable
~heel is in the first and ~e~ond pivot limits.
The described automatic steering ~omponents operate
25 2s follows. Assuming that the machine is in the first
turn condition, an outward-rearward displacement of the
first locating member exceeds such a displacement of the
~econd locating member, the extension of the f irst
-.onitoring bar in its first monitoring direction exceeds
the extension of the second monitoring bar in its second
~onitoring direction~ and the monitoring wheel is
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displaced in the first monitoring direction. The
i n,onitoring wheel and accompanying switch activating
member activates ~he ~irst monitoring switch. Then,
being activated by the pivoting control means, the
pivoting means pivots the steerable wheel toward the
first pivot limit. Once the first pivot limit is
attained, the first limit switch causes the pivoting
control means to halt the pivoting of the steerable wheel
which keeps the steerable wheel in the first pivot limit.
The chassis now turns toward its first side. When the
chassis is in the second pivot limit, a mirror image of
~ the process just described oceurs, wherein the row
l monitoring means and the pivoting control means, cause
the steerable wheel to pivot toward the second pivot
limit, the pivot limit monitoring means and the pivoting
control means keep the steerable wheel in the second
;; pivot limit, and the chassis turns toward its second
:i side. Angles between the first and second pivot limits
and the alignment axis are preferably about three to five
degrees.
Now, the general features of the automatic machine
shutdown means are detailed. Eacb displacement of one of
i the locating members constitutes a displacement signal,
;/ Thus, in the process of locating the row, the automatic
~5 steering means generates a plurality of such displacement
signals. The automatic machine shutdown means stop the
:` operation and loco~otion of the maehine when a
predetermined amount of time elapses wi~hout any
. displacement signal occurring.
-, 30 The automatic machine shutdown means functions as
follows. Near the first and second monitoring bars, a
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plurality of displacement monitoring shitches are
positioned in a way that enables the switches to sense an
extension of either of the monitoring bars. Such an
extension indicates displacement of the f irst and second
5 row locating members. Time measuring means which
co~municates with the displacement moni~oring switches
~easures time elapsing between displacements of the
locating members. If a predetermined amoun~ of ti~.e
elapses without any such displacement occurring, t~.en
10 ~.achine shutdown ~eans operatively connected to the time
me asur ing means shuts down the machine.
O~her features of the present invention will become
apparent from the following descr iption.
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BRIEF DESCRIPTION OF THE DRAWIl~GS
PIGURE 1 is a plan view of a harvester embvdying the
teachings of the present invention, with portions of the
body and a housing, which cove~s a rack and gear
assembly, removed for purposes of illustration:
FIG~RE 2 is a front end view of the harvester of
Figure 1~ illustrating just a chassis, ground wheels, and
certain components of the present invention;
FIG~RE 2A is a front elevational view of a steerable
h~heel Df the present inven~ion moun~ed to a harvesting
machine's chassis, with position monitoring components;
FIGURE 3 is a view similar to Figure 1 ~howing
operation of components of the present invention;
FIGURE 4 is a plan view of a rack and gear assembly
of the invention, with a portion of its housing re~oved;
FTGURE 5 is a plan view of a steerable wheel of the
present invention shown in a first and a second pivot
limit;
FIGURF 6 is a circuit diagram including steering
control and safety component~ of the present inYention;
FIG~RE 7 is a plan view of a p2th along which a
.achine employing the teachings o~ the present invention
travels;
FIGURES 8A through 8F are schematic views of row
.onitoring components, row loc3ting bars, and a steersble
~ ~heel of the present invention in v~rious conditions of
,~ opera~ion;
FIGURE 9 is a diagram o~ a hydraulic drive system of
a harvester employing features of the present invention;
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FIGURE 10 is a diagram of logic ~sed in the present
invention.
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DESCRIPTION OF THE_PREFERRED EMBODIMENT
A preferred embo~iment of ~he invention is directe~
~oward an automatic steering means 4 and an automatic
machine shutdown means 8 by which a machine 10, used in
harvesting or in other agricul~ural operations, is
located laterally with respect to a rvw 12 of crops ~hich
the machine 10 is tending and also is shut down in
situations to preven~ accidents in the operation of t~,e
~,achine 10.
Before describing the components of the automatic
means 4 and 8 in summary and in detail, it is believed it
would first be helpful to desoribe the machine 10 and the
machine's environment. As shown in Figures 1, 2, an~ 3,
the row 12 of crops comprises a plurality of plants
certain portions of which, for instance stem portions 13
thereof, provide the machine 10 with a means of guidance
for steering along the row 12. These portions 13 are
used by the automatic steering means 4 as an index for
locating the position of the row 12 with respect to the
machine 10 and by the automatic ~achine shutdown means 8
or generating displacements of row loca~ing members, to
be described below, to indicate whether the row is
pre~ent or absent. Accordingly, the portions 13 provide
first and second lateral locating indices 15 and 16,
which are surfaces tha~ the locating members to be
described engage laterally, and a row axis 17 which is
located centrally between the lateral indices 15 and 16.
Additionally, the plants in the row 12 have upper foliage
portions f.
To continue describing the machine's 10 environ~,ent,
agricultural operations, as indicated in Figure 1~ are
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performed by the machine 10 as follows. As the machine
10 moves along the row 12, the row 12 enters and passes
rearwardly thro~gh an enclos~re 18 in the machine 10,
where two banks of 3gricultural operating eg~ipment 19,
5 positioned on either side of the enclosure 18~ perform
agr icultural operations such as harvesting on the row 12.
The equipment 19 includes crop beating means for
dislodging produce from the crops.
Also, in terms of structure, as Figures 1 and 2 show
best, the machine 10 itself comprises a chassis 20 and a
body 21. To support and steer the chassis 20, the
chassis 20 is mounted on two n~n-steerable ground
wheels 24 and a turning means~ such as a steerable
wheel 28, mounted on a pivot mounting means 36 f~r
pivoting about a vertical axis 38 of ~he wheel 2B as
shown in Figure 2. The chassis 20 then is the illternal
frame which connects the s~ceerable wheel 28 in front and
the two rearward drive wheels 24. As Figure 1 show~, the
bc>dy 21 comprises an attendant 's portion 40 and an
operating por~cion 44 connected together by a structl~ral
member 45~ which is considered part of the chassis 20.
q The structural member 45 is able to move vertically up
and down ~dith respect to the rear wheels 24, thereby
r2ising and lowering the operating portion 44 to which
the structural member 45 is connected. The portion 40
!~ provides the attendant with a supporting platform which
allows riding upon the machine 10 and a steering
- wheel 48, rotation of which pivots the steerable wheel 28
for on-the road steering and other maneuvering, ~uch as
maneuvering in headlands. The ~perating portion 4g has a
forward end member 52 which connects two sidewalls 56.
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The paragraphs that follow first summarily describe
the functioning of the automatic steering means 41 this
description being followed by a more detailed
description. ~dditionally, the automatic shutdo~n
means 8 is addressed both generally and specifically.
To summarize the automatic steering means 4, it
include5 the following functional components: a row
locating means 60 (Figures 1 and 8), a monitorins
means 61, ~nd a s~eering control means, which comprises a
10 pivot position monitoring means 62 and a pivoting control
means 63 (Figures 5 and 6). As shown primarily in
Figures l through 3~ the row locating means determines
; the relative loca~ions of the machine lO~ in particular,
as shown in Figure~ l and 3, a fixed alignment location
15 or centerline 64 of the machine 10, and the row axis 17.
In effect~ as Figure 3 shows best, the row location
means 60 measures first and second row locating
~uantities A and B that) respectively, are distances from
the centerline 64 to the ~irst and second lateral rvw
2a indices l~ and 16~ The monitoring means 61, shown best
1 in Figures 4 and 6, performs multiple functions as part
i of both the au~omati~ s~eering means 4 and the automatic
machine shu~down means 8: it monitors the location of
the machine 10 relative to the row 12, as indicated by
the row locating quantities A and B, for automatic
steering purposes; also, it monitors displacement signals
i senerated by displacements of row locating members caused
by the indices 15 and 16, or automatic shutdown
purposes. To focus on automatic steer ing, whereas the
row locating means 60 communicates the quantities A and B
to the monitoring means 61, the monitoring means 61 uses
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the guantities A and B to identify first or second ~urn
conditions that e~ist, respectively, when the align~ent
location 64 is spaced laterally more than a predetermined
distance from the row axis 17 on the first or second
sides of the row 12, respectively. In accordance ~ith a
feature of the invention, the turning means 28 has first
and second pivot limits, which are angularly displaced on
vpposite sides from a straight ahead alignment axi~ ~to
be discussed in connection with the pivot limits in the
text below). The monitoring means 61 imparts to the
steering control means turn condition signals indicating
the existence of the irst or second turn conditions; in
response to these signals, the steering con~rol means,
hhich is operably connected to the steerable wheel 28,
position the steerable wheel 28 at the firsS or second
pivot limits, that is, when the first or second turn
conditions, respectively, exist, the steerable wheel 28
turns fully to the first or second pivot limits,
respectively. The pivoting contrvl means 63 ~which
~igure 6 illustrates) initiates pivo~ing of the turning
means 28 toward one or the other of the pivot limits and
ceases the wheel's 28 pivoting when the limit is reached.
The pivot position monitoring means 62 ~which is shown
primarily in Figures 5 and 6), which communicates
operatively with the pivoting control means 63 monitors
the position of the steerable wheel 28.
~ aving described in general terms basic components
~ithin the automatic steering means 4, the discussion now
turns ~o a detailed description of these components. To
commence with a description o the row locating means 60,
illustrated mostly in Figures 1 through 3, the mean~ 60
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first includes a row locating assembly 72 for measuring
the row locating quantities A and B by engaging the first
and second lateral row indices, respectively, with firs~
and second row locating members 88 and 89 which the
indices 15 and 16 displace laterally upon such
engagement. Two row locating assemblies 72 are
positioned in a forward part and on either side of the
enclosure 18. Each of the two assemblies 72 positions
its row locating member 88 and 89 parallel for lateral
engagement therebetween with the two indices 15 and 16.
Two locating shafts 90 rotate in response to lateral
displacement of the locating members 88 and 89 to
indicate a displacement o~ the row locating members &8
and ~9. As Figure 2 shows best, each of the two locating
shafts 90 is mounted rotatably to a xelated one of the
two sidewalls 56 by a plurality of mounting means 91. A
rearward end 92 of each row locating member 88 and 89
connerts hingedly to a rear supporting link 96, and each
rear link 96 connects fixedly to one of the two locating
~0 shafts 90, th~s linking mechanically each row locating
;l member 88 and 89 to its related shaf t 90. Two forward
supporting links 100 each connect hingedly to one of the
two row locating members 88 and 89 forward of the rear
links 96. ~ach rear link 100 is connected hingedly to
its related sidewall 56 by a mounting means 104.
Figure 3 shows best the configuration of the row locating
members 88 and 89. Each row locating member 88 and 9
has a forward portion 108, a middle portion 112, and a
rearward portion 116. A forwardly and ou'cwardly curve~
30 conf iguration of each forward portion 108, as shown in
Figure 3~ is intended to prevent jamming of the
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components of the machine 10 when the machine 10
encounters plants in the row 12. ~he middle portions 112
both align parallel to the two ~idewalls 56. Each
rearward portion 116 in practice aligns with its related
5 middle portion 112, as sh~wn in Figures 1 and 3. As
Figures 1 and 3 show, the ~ow locating members 88 and 89
are suf f iciently long in relation to distances between
tl e index portions 13 of the plants in the row 12 so that
the row locating members 8~ an~ 89 engage at least two of
10 the portions 13 at a time. The two forward portions 108
of the members 88 and 89 define a rearwardly converging
throat 124 which rece;ves plan~s of the row 12 as the
plants enter the enclosure 18. As mentioned, the row
loca~ing assemblies 72 sgrv~ to i~e~p the members 88
15 and 89 parallel to the two sidewalls 56 and to mount the
locating members 88 and ~9 fvr rearward and outward
displacement as the members 8B arld 89 engage the ro~
indices 15 and 16. This is accomplished by two par21lel
linkages as follows. Each of the row locating members 88
20 and 89 and one o~E the ~cwo Tear linlcs 96, sidewalls 56,
and forward links 100, define a parallelogram 128: hence
parallel linkages. (Figure 3 illustrates only one of the
two parallelograms 123, namely, the one correspondin~ to
member 88. ) As each of the row locating members 88
and 89 moves rearwardly and o~twardly, this displacement
of that row locating member ~8 or 89 rotates its related
locating shaft ~0. Such rota~ion o the locating
shafts 90 is a function of the rearward and outward
displacemen~ of the row lo~ating members 88 and 89.
30 ~esilient means, which is illustrated in Figure 1 an~ 3
as two spr ings 132 conne~ted be~ween a related one ~f the
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fosward links 100 and the forward members 52, cause. the
row locating assemblies ~o press externally on the sides
Of the row 12. When the row 12 is absent, the assemblies
hold the members 88 and 89 in a neutral position 133,
5 shown in Figure 1.
Figures 1~ 3, and 4 illustrate the row monitoring
means 61 which communicates with the row locatins
assemblies 72, just described, to monitor the location Of
the machine 10 in relation to the row 12. This is
accomplished by the monitoring means 61 sensing the
displacement of the row~locating members 88 and 89,
causing it to impart the turn condition signals to the
pivoting control means 63. As Figure 4 shows, first and
se~ond parallel monitoring bars 141 and 142 define
therebetween a monitoring pathway 148. The monitoring
bars 141 ~nd 142 perform dual functions because they
register the displacements o the locating members 88
and 89 caused by engagement with the indices 15 and 16,
thus monitoring the location guantities A and B that
indicate the machine's 10 lateral position, and they also
indicate the displacement signals, i,e., the
displacements of tbe locating members 88 and 89, for
automatic machine shutdown purposes. ~o turn the
discussion to the monitoring bars' 141 and 142 functions
2S in automa~ic steering, ~hey cooperPte with a monitoring
wheel, tO be described shortly to find the difference
between the quantities A and B, ~hereby monitoring the
first and ~econd turn conditions. The first monitoring
bar 141 is slideably mounted for linear extension
3D ~iovement in a first monitoring direction 152 and for
retraction in a second monitoring direction lS6. The
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second monitoring bar 142 is similarly mounted to be able
to extend in the second monitoring direction 156 and to
retract in the first monitoring direction 152, the
motions of the two bars 141 and 142 being independent.
To enable the first and second monitoring bars 141
and 142, respectively, to communicate wi~h the first and
second locating members 88 and 89, the first and second
monitor ing bars 141 and 142 are respectively linked
mechanically to a related one of the locating shafts 90
via first and second locating-monitoring communication
linkages 160 and 164, shown best in Figure lo Each of
the two locating~monitoring communication linkages 160
and 164 comprises a crank arm 1~8~ which serves as ~
crank attached fixedly to one of the locating shafts 90,
and a crank-monitoring c~upler 170 which connects
hingedly to a related one of the two monitoring bar~ 141
and 142. Each crank arm 168 connects hingedly to its
related crank-monitoring coupler 170. Consequently,
outward, rearward displacement of the ~irst and second
row locating members ~8 and 89, respectively~ extends the
first and second monitoring bars 141 and 142,
respectively, ~rom their neutral positions in the first
and second monitoring directions 152 and 156. When the
first and second row locating members 8B and 89 are
displaced inwardly and forwardly, the process reverses:
the respective first and second mon;toring bars 141
and 142 retract, with the first m~nitoring bar 141
retracting in the second monitoring direction 156, and
the second m~nitor ing bar 142 retracting in the first
monitoring direc~ion 152.
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As Figures 4 and 8 show, a ~.onitoring wheel 172
positioned between and engaged with the two monitoring
bars 1~1 and lq2 senses differences between the
displacements of the first and second row locating
bars 88 and 89. As figure 4 shows, the wheel 172 is a
toothed gear 172 and the monitoring bars 141 and 142 are
toothed racks 141 and 142, which engage the teeth of the
gear 172. As Figure 8A shows, assuming the exteneion of
the first monitoring bar 141 from its neutral position in
the first monitoring direction 152 is greate;r than the
extension of the second monitoring bar 142 rom its
neutral position in the second monitoring directiofl 156,
then the monitoring wheel 172 is displaced from a neutral
position 174 (in the monitoring pathway 148) in the first
monitoring direction 152. As Figure 8B shows, if the
extension of the second monitoring bar 142 in the second
n.onitoring direction 156 is greater ~han the extension of
the ~irst monitoring bar 141 in the first monitoring
direction 152, then the monitoring wheel 172 is displaced
from its neutral position 174 in the second monitoring
direction 156.
As Figures 8C, 8D and 8E respectively show that a
disposition of the monitoring bars 141 and 142 in their
neutral position, a minor equal displacement of the
ba.rs 141 and 142, and a substantial equal displacement of
the bars 141 and 142 all leave the monitor ing wheel 172
in its neutral position 174. In Figure 8C, 8D and 8E,
the steerable wheel 28 has remained angularly displaced
from its straight ahead position; this is because the
30 automatic steering means 4 causes the steerable wheel 28
to move from a pivot limit location in which the
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s~eerable wheel 28 is found only when the turn condition
changes, that is, only when the monitoring wheel l,2 has
.oved from one side of its neutral position 174 to the
other side thereof. Hence, in the Figures 8C, 8D and 8E
5 the wheel 28 will not pivot from the position in ~hich it
is shown until the monitoring means 160 registers a
change in the turn condition.
As Figure 4 shows best, to mount the components of
the monitoring means 61 operably, ~here are provide~ a
bar-shaped movable housing 176, in which the monitoring
wheel is pivotally mounted for engagement wi~h the
~.onitoring bars 141 and 142, and a fixed housing 164, in
which the monitoring bars 1~1 and 142 and t.he movable
housing 176 are mounted slideably ~or mutually parallel,
lateral back and forth movement. The movable housing 176
supports and guides the monitoring wheel 172 and it
activates row monitoring switches described immediately
below in connection with the turn condition signal. For
pivctal mounting of ~he wheel 172 in the movabl~
housing 176, ~he wheel 172 is ~onnected to a pivot
pin 186 connected pivotally to the housing 176. To guide
the movable housing so as to maintain parallel rela~ion
thereof with the monitoring bars 141 and 142, ~he
stationary housing 184 provides a guide member 188 with a
longitudinal straight edge 1~9 along which the mova~le
housing 176 runs. A longitudinal channel 190 with two
sides 191 in the fixed housing 189 enables the monitoring
w~.eel ~72 to move freely back and forth.
To generate turn condition signals tha~ indic~e the
e~istence of the first or second turn conditions,
respectively, first and second row monitoring
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shitches 201 and 202 are provided, as Fig~re 4 shows,
these being supported by and positioned in the fixed
housing 184. The method by which the monitoring means 61
senses a difference in the displacements of the row
locating members 88 and 89, and thus the existence of the
first or the second turn conditions, includes these
Steps the difference in the displacements of the row
locating members 88 and 89 appears as a difference in the
displacements of the moni$oring bars 141 and 142 from
their neutral positions which causes a displacement of
the monitoring wheel 172 from its neutral position 174 in
the f irst or second monitoring directions 152 and 156~
respectively, indicating the existence of the first or
second turn conditions. As Figure 4 shows, the first and
second monitoring switches are activated by the movable
housing 176 in a manner such that activa~cion of the first
or second switches 201 and 202, respectively, indicates
displacement of the monitoring wheel 172 (and the muvable
housing 176) from the neutral position 174 in the first
or second monitoring direc~ions 152 and 156.
In discussing the generation o~ turn condition
signals ~urther, details about the nature and the
positioning of the switches 201 and 20~ are addressed.
In terms of their nature, the switches 201 and 202 are
proximity sensing switches which sense the proximity of
the movable h~using 176: a preferred one of several
possibilities is ~o use metal proximity sensing switches.
As for the positioning of the switches 201 and 202, a
sufficient distance should be provided between the
switches 201 and 202 and the movable housing 176 in its
neutral position to prevent both of the switches 201
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and ?02 from sensing the movable housing 176 a~ the same
ti~e: preferably, the s~ ches 201 and 202 should be
located quite close to the movable h~sing 176 in its
neutral position 174. Presumably, this distance should
be about one thirty-second of an inch; a greater distance
delays the row monitoring switches 201 and 202 's
responses to displacements of the movable housing 176.
Referring still to Figure 4, the movable housin9
maintains sensory contact with either one Gr the other Of
the two switches 201 and 2020 hence, the movablQ
hou~ing 176 should have a sufficient length 192 to
prevent the movable hol~sins 176 from losing sensory
contact with the switches 201 or 202 as the movable
housing 176 moves back and forth.
~o correct the location of the machine 10 laterally
relative to the row 12, as Figure 5 shows, the steerable
wheel 28 has a first pivot limit 211 and a second pivot
limit 212. As Fi~ures 1 and 3 show, when the steerable
wheel 28 is at the first or second pivot limits 211
and 212, respectively, it turns the machine 10 toward
f irst or second sides 213 and 214 of the machine 10
(corresponding respectively to the îirst and second row
locating members 88 and 89). For purposes of
illustration; Figure 5 shows an alignment axis 218
25 representing the directiorl in which the machine 10 is
traveling when moving alvn~ the row 12. The f irst and
second pivot limits 211 and 212 of the steerable wheel 28
are angularly displaced on opposite sides from the
alignment axis 218.
30 ~ To enable pivoting of the steerable wheel 28 to halt
when the steerable wheel 28 has attained either the f irst
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or second pivot limit 211 and 212, the pivot position
monitoring means 62 shown in Figure 5~ imparts a limit
signal to the pivoting control means 63 that halts
pivoting of the steerable wheel 28 and keeps the wheel 28
5 positioned ~t the first or second pivot limits 211
or 212u The pivot position monitoring means 62 comprises
a movable angular displacement indicator 220 which pivots
wi~h the steerable wheel 28 and first and second limit
s~itches 223 and 224 fixed to the chassis 20~ The
10 ang-~lar displacement indicator 220 activa~e~ ~che first or
second limit switches 223 and 224, respe~tively, when the
steerable wheel 28 is at the f irst Ol second pivot
limits 211 or 212. Inasmuch as the angular displacement
indicator 220 is an arc-shaped member fixed to a
pivotable part of the mounting means 36 for the steerable
wheel 28, it travels through an angle, which includes the
first and second pivot limits 211 and 2120 As it pivots,
it describes a path. The first and second limit
sh~itches 223 and 224 are positioned adjacent to that path
in a manner such that the first or second limit
. s~itches 223 or 224, respectively, are activated when the
, steerable wheel 28 is at the first or second pivot
j limits 211 or 212.
~t is to be noted that the steerable wheel 28's
pivotable mounting means 36 comprises elements as shown
in Figure 2A: a member 225 which connects to an end 226
of a transverse axle 227 of the steerable wheel 28 on
which the wheel 28 rotates; a vertical pivoting pin ~29
which is ~ixedly attached to the member 225 and which
30 enables the pivotable mount 36 to pivot about the
vertical axis 38 of the steerable wheel 28~ connected
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~323~7
f ixedly to an upper portion of the member 225 and
pivotally to the chassis 20 by a pivotal mounS 230~ The
first and second limit switches 223 and 224 are fixed to
the machine 10 while the angular displacement
indicator 220 (visible in Figure 5) is fixed to a mov~ble
pivoting component, such as the piYOting pin 229, of the
pi vo table mol~nt 3 6 .
To pivot the s~ceerable wheel 28, there is provided a
pivoting drive means 231, shown in Figure 5, which
10 compr ises a ~onventional hydraulic dr ive cylinder 232
with one end f ixed to the machine 10, a jack arm 240 and
a pivot lever 244 operatively connected to the steerable
wheel 28. As Figure 5 ~hows, linear retraction or
extension, respectively, of the jack arm 240 in the
cylinder 232 moves the steerable wheel 28 toward the
first or second pivot limits 211 and 212.
As shown in Figure 6~ a control circuit 272 is
operatively connected to the main harvesting eq~ipment 19
(of Figure 1) in the machine 10, equipment for
20 automa~ically steering, and automatic machine shutdown
equipment. The control circuit 272 comprises three
subcircui~s. Firsty a coordination circuit 273 assures
that the a~tomatic steering 4 and the automatic
shutdown 8 operate only when the main harvesting
e~ipment 19 is on, Second, an automatic steering
control circuit 274 transmits tS~e turn condition signals
fron the row monitoring means 61 and the pivot position
monitorinq means 62 to the pivoting con~rol means 63
thereby enabling the means 63 to control pivotirlg of the
30 steerable wheel 28 to pivot in response to the relative
locations of the machine 10 and the row 12. Third, an
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1323~P~ ~
automatic machine shutdown circuit 275 responds to
signals from the automatic shutdown system 8. Electric
power is supplied from an electric power source 280
directly to the coordination circuit 273 and indirectly,
via the coordination circuit 273 and a power line 284, to
the automatic steering control clrcuit 274 and the
au~omatic n,a~hine shutdown circuit 275.
Before turning the discu~sion to the details of the
individual subcircuits, it is to be noted that the
piv~ting control means 63 of the automatic s~eering
means 4 compr ises essentially a contrc~l valve 276, shown
in Figure ~, which is to be discussed below in connection
with the automatic ~teering control circuit 274.
To describe the co~rdinating circuit 273, as shown
in Figure 6, a positive terminal of the electrical power
source 280 connects through a main power switch 292 and a
line 296 to an electric solenoid which activates the
operating equipment 19, such as the beater rods that
engage the crop row 12 to remove the product therefrom~
The main on/off switch 292 and ~ coordinating on~off
st~itch 300 must both be closed in order for the re~.aining
circuits of the control circuit 272~-i.e., the automatic
steering circuit 274 and the automatic machine shutdown
circuit 275--to operate. This is because the power
25 source 2P~0 connects in series via the main on/off
shitch 292, a line 301, and the coordinating on/off
sh~itch 300 to the remaining circuits 274 and 275.
Before describing in detail the circuitry 2ï4 for
'che automatic steering, more details of the electrically
30 actuated control valve 276 of the automatic ~teering
means 4 are provided, referring still to Figure 6. The
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control valve 276 connects operatively to the pivoting
drive means 231 to cause the steerable wheel 28 to do
three thinys: pivot toward the first pivot limit 211,
cease pivoting, or pivot toward the second pivot
limit 212. The control valve 276 comprises a main valve
element 306 having a reverse flow ~ection 307, a middle,
off section 308, and a forward flow section 309, the
three sections 307, 308 and 309 of the element 306 being
selectively connected to the hydraulic cylinder 232 to
direct hydraulic fluid in a manner to control the
pivoting of the steerable wheel 2~ as described~ First
and second solenoids 311 and 312 are operatively
connected to opposing ends of ~he control valve 276 to
magnetically draw the element 306 in opposing directions.
~ence~ as F~gure 6 shows, energization of the first or
second solenoids 311 or 312, respectively, draws the
element 306 so as to align th~ sections 307 or 309,
respectively, for reverse or forward flow, respectively,
of pressurized fluid, which initiates pivoting of the
steerable wheel 28 toward its ~irst or second pivot
limits 223 or 224, respectively. When the current is
off, neither of the solenoids 311 or 312 draw the
element 306. Accordingly, resilient means in the control
valve 276 positions the element 306 so that the off
25 section 308 thereof is aligned to stop ~Elui~ flow,
causing pivoting of the steerable wheel 28 to cease. The
solenoids 311 and 312 are grounded by two separate
grounds 314.
To describe the automatic steering contr~l
circuit 274, as discussed previously in connection with
the turn condition signals, the monitoring means 61
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includes ~he first and second row monitoring switches 201
and 202 as shown in Figure 6. In the circuit 274, the
row monitoring switches 201 and 202 are normally openO
The circuit 274 also includes the two limit switches 223
and 224, also discussed previously in connection ~ith the
pivot position monitoring means 62, tha~ are normally
Closed. As Figure 6 shows, in the circuit 274, the first
and second row monitoring switches 201 and 202,
respectively, are co~nected in parallel via the first and
10 second limi~ switches 223 and 224, respectively, to the
first and second solenoids 311 and 312 of the control
valve 276, respectively. That is, the power line 284
sives power to the two row monitoring switches 201
and 202 via two separate branch lines 315; then, the
15 ~ir~t row monitoring switch 201 connects, via a line 348,
the first limit switch 223, and a line 352, to the first
solenoid 311; the second row monitor ing switch 202
connects, via a line 356, the second limit switch 224,
and a line 360, to the second solenoid 312.
2~ Additionally, the following points ase to be noted: the
control valve 276 receiYes pressurized hydraulic fluid
from a fluid source 316 and it returns hydraulic fluid to
a fluid reservoir 320; the control valve 276 connects
operatively via two separate hoses 324 and two separate
25 ports 328 of 'che cylinder 23? to opposite sides of a
piston 336 within the c:ylinder 232.
Elaving described ~Lhe au~omatic steering circuit 274,
operation of tl-e automatic ~teering means 4 using the
automatic steering circuit 274 is now addressed,. In
30 operation, the automatic steering means performs as
~ollows. As ~hown in Figure 8C, when there is no row 12
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between the locating ~embers 88 and 89, the members 8e
and 89 are nearly toge~her~ As Figure 8D shows, and as
mentioned previo~sly, introduction of the row 12
displaces the sensing members 88 and 89 ou~wardly and
rearwardly. As Figure 8A shows r and also as previously
mentioned, assuming that the machine 10 is steered too
far with respect to the row 1~2 ~oward the machine 's
side corresponding to the second row locating member 89,
the displacement of the first row locating member 88
exceeds the displacement of the second rvw lpcating
member 89. Consequently~ as Figure 6 shows, the
monitoring means 61, by closing the first row monitoring
switch 201, imparts the tusn condition signal to the
control valve 276 for initiating pivoting movement of the
steerable wheel 28. This energizes the first
solenoid 311 ~f the control valve 276 which directs
pressurized fluid to the cylinder 232 of the pivoting
drive means 231 retracting the piston arm 240 and
pivoting the steerable wheel toward the first pivot
limit 211. Referring still to Figure 6, when the
~teerable wheel 28 reaches the first pivot limit 211,
this opens the Pirst limit ~witch 223, breaking the
circuit to the f irst solenoid 311, which aligns the
section 308 of the valve element 306 to stop fluid flow
ceasing the pivoting of the steerable wheel 28.
~eturning to Figure 8A, this le~ves the steerable
wheel 28 at the first pivot limît 211 (the sequence just
described, including this attitude 211 of the steerable
wheel 28, is also shown in Figure 3), then, the
machine 10 steers toward its first side 213 which brings
the centerline 64 of the machine 10 back toward the row
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1323~87
axis 17 of the row 12. Assuming that the centerlin~ 64
of the machine 10 crosses the row axis 17 making the
machine 10 off-center to the opposite side 15 of the
ro~ 12, in a sense there occurs a mirror image of the
above-described sequence, as Figure 8B indicates.
Because the subsequent steps axe identical to the
described steps; further detailed description of those
steps is deemed unnecessary, except to note that the
steerable wheel 28 assumes the second pivot,limit 212, as
shown by the at~itude 212 of the steerable wheel 28 in
Figure 8B, and turns the machine 10 toward its second
side 214, thus brining the centerline 64 of the
machine 10 back to the row axis 17.
As Figure 7 shows, in the machine's 10 normal
15 operation, it describes a path 368 that consists of a
plur~lity o~ alternating first turns 371, during which
the steerable wheel 28 is at the first pivot limit 211
and the machine 10 steers toward its first side 213, and
second turns 372, during which the steerable wheel 28 is
20 at the second pivot limit ~12 and the machine 10 steers
to-~ard its second side 214. In short, the machine 10
experiences a cyclical steering pattern charactelized by
repeated turns.
Before turning to a description of the automatic
25 machine shutdown ~ean~ ~ ;t is thought that
supplementary information will assist the reader. In
harves~ing berries, berry plants may be grouped in a
plurality of ~hills" 376, which Figure 7 shows, in effect
tight groupings of individual vines which are estilr,ated
30 to be roughly 30" apart. ~bese steering cycles of the
machine can be quite regular, cycling completely between
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~323987
the first and second turns 371 and 372 about once for
every two hills, or it may be ~hat the machine 10 will
travel a longer distance before initiating a new turn.
It is to be noted that an angle which Figure 5 shows
S between the first pivot limit 211 anù the alignmen~
axis 218 and an angle be~ween the second pivot limit 212
and the alignment axis 218 should ~e within the ~ollowing
range. These angles should be sufficiently large,
considering the speed of the ma~hine 10, to provide
adequate correction of steering errors~ In practice with
berry harves~ing the bersies being planted in the
descr ibed hills 376 of Figure 7~ a minimum angle o three
degrees from the ali~nment axis 218 can provide an
adequate correc~ion capa~ y a~ a speed of
15 one-and-one-half miles per hour. Additionally, these
angles should be suffici~ntly sm~ll to give the steerable
wheel 28 adequate time ~o rotat~ ~etween the pivot
limits 211 and 212 befo~e a new change in the ~urn
condition occursO It is ~stimated that a maximum angle
20 of f ive degrees between the pivot limits 211 and 212 and
the alignment axis 218 is appropriate. This is a
correctiorl on the order of about 2" for a travel ing
distance along ~he row ~f 307' ~2.1" = 30" x tan 4).
Also, with many kinds of plants such as berry bushes
25 or vines, the stem portion 13 of the plant is usalble as
an index for automatic steering guidance.. E(ow locating
members 88 and 89 are adaptable to different kinds of
indices, which provide the basic dual, lateral indices 15
and 16 which the present invention employs., As Figure 2
30 shows, with plants having stem p~tions usable as
indices, the row locating mem~ers 88 and 89 should be
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~323987
positioned lo~ eno~gh so that they engage the stem
portion 13 rather thar, the foliage portion F.
Additionally, as Fig~re 1 illus~rates, when ~he row
locating assemblies 72 are in their central, neutral
positions 133, the ro~ locating members 88 and 89 should
be sufficiently close to one another to assure that they
respond to plants of the smallest diameter in the row 12.
For instance, with berry plants, when the row locating
assembly 72 is in i~s neutral position 133, the row
locating members 88 an~ B9 should be about ~ne inch
apart.
As indicated i~ Figure 3~ the capacity o~ the
automatic steering means to aacommodate the widest plants
depends upon the capacity of ~he resilient means 132 to
extendl the freedom of the row locating members 88 and 89
to move outwardly and rearwardly~ the width a
passageway 391 def ined between two crop receiving
hoods 398 f ixed to the iEorward end of the ohassis 20 of
the machine 10l and a capacity ~r lateral movement of
20 the row monitori~g wheel 172 and the movable housing 176.
In berry harvesting, the lateral displaoement c3pacity of
each row locating member 88 and 89 believed necessary
from the alignment location ~4 of the machine ;s about
eleven inches,
If an aberration, such as a stray rock, ~omes in the
path of the row locating members 88 and %9, assuming such
an aberration displaces only one of the row loca~ing
members ~8 and 8g~ as ~igure 8F shows5 the automatic
steering means 4 auto~T.atically limits its ~ensitivity to
30 the aberrationO Ina~ltuch as the row monitoring wheel 172
is displaced only half an amount of displacement as one
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~3~3~87
of the monitoring bars, ill~stra~ed as the second ro~
monito~ing bar 142, the sensitivity of the row monitoring
wheel 172 to the aberration is lessened.
Figures 4, 6 and 9 best illustrate the automatic
machine shutdown means 8. The automatic machine shutdown
means utilizes displacement signals generated by the
automatic steering means 4, indicating displacement of
the row locating members 88 and 89, to sense the presence
or the absence of the row 12. As discussed previously in
connection with the monitoring means' 61 multiple
functions, the means 61 indicates these displacement
signals by linear movement of the first and second
monitoring bArs 141 and 1~20 A displacement signal
sensing means 400, indicated in Figure 4, senses these
movements of the irst and second moni~oring bars 141
and 142, and imparts displacement signals ~o a machine
shutdown means described below. The machine shutdown
means monitors time which elapses between the
displacement signalsO Then, if a predetermined amount of
time elapses without any displacement signals occurring,
the machine shutdown means halts the operation and the
locomotion of the machine 10.
To sense the displacement signals, the displacement
signal sensing means 400, as Figure 4 shows" comprises a
plurality of displacement sensing switches described
shortly. As they move back and forth/ the first and
second monitorinq bars 141 and 142 describe linear
paths 408 comprises in Figure 4. The displacement
sensing means 400 locates a plurality of displacement
sensing switches 415 located adjacent to the paths 408 of
the first and second monitoring bars 141 and 142 in a
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~ 323~7
r,anner such that the switches 415 sense any displacement
of ~he first and second row locating bars 88 and 89
occurrir~g. Proximity of the first and second row
monitoring bars 141 and 142 to the displacement signal
sensing switches 415 activates the switches 415~ A
preferred one of several possibilities is for the first
and second monitoring bars 141 and 142 to comprise metal
and the displacement signal sensing switches 415 to be
metal proximity sensing switches.
To halt the movement and operation of ~he
machine 10, there is a machine interruption means, which
Figure 9 illustra~es. Figure 9 shows a hydraulie
locomotion and operation system 422 for the machine 10.
A hydraulic pump ~24 provides pressurized hydraulic fluid
to operation components 428 and locomotion components 432
of the machine 10. Operation components 428 include
means for carrying out certain operations of the
machine 10~ such as belt-type produce catching system
used in harvesting~ Machine locomotion components 432
propel the machine 10. A machine interruption means 43
shuts off the flow of pressurized hydraulic fluid ~o the
operating components 428 and the locomotion
components 432 thereby halting the operation and
locomotion functions. A ~luid artery 440 provides
pressurized fluid from the pump 424 to the operating
components 428 and the locomotion components 432. Fluid
return means 444 returns hydraulic fluid from the
operating and Iocomotion components to the pump 424. The
interruption means 436 which is electrically activated,
simply connects the fluid artery 440 directly to the
fluid return means 444~ completely bypassing the
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1323~7
operation components 428 and the locomotion
co3ponents 43~.
The automatic machine shutdown circuit 275 of
Pi~ure 6 enables the displacement signal sensing
5 s~-itches 415 to communicate operably with a machine
s~n~tdown means 472. The machine shutdown means 472
co~prises the operation locomotion interruption
~,eans 436, just described, and a clock means 476. The
clock means 476 measures time which elapses between the
occurrence of displacement signals. If a predetermined
a~ount of time elapses wi~hout any displacement signals
occurring, the clock means 476 activates the operation
lo_omotion interruption means 436. A line 480 enables
the clock means 476 to communicate with, and activate,
tt.e operation locomotion interruption means 436~ The
clock means 476 activates the interruption means 436 when
the clock means 476 receives electric power continu~usly
for the predetermined amount of time. An interruption in
the power supplied to the clock means 476, resets the
cl~ck means 476. The displacement signal sensing
s~itches 415 are normally closedO Accordingly~ if the
predetermined amount of time lapses without a
displacement signal occurring t ~he displacement signal
sensing switches will allow power to be conducted through
the automatic machine shutdown circuit 275 continuously
tc the clock means 476.
The automatio machine shutdown circuit 275, as
Fi_ures 6 shows, is wired to respond to displacement
si^nals as follows. The two displacemen~ signal sensinq
s~itches 415 are wired in series to the electrical power
so~rce 280; the machine shutdown means 472 and the
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displacement signal sensing switches 415 are also
connected in series. In detail, the two displacement
signal sensing switches 415 are mutually connected by a
line 496. One of the displacement signal sensing
switches 415 connects directly to the power line 284; the
other displacement signal sensing switch 415 connects ~o
the machine shutdown means 472 by a line 482.
Additionally, the automatic machine shutdown
circ~it 275 includes supervision assurance means 484 for
assuring that the operation and locomotion functions of
the machine will operate only with the supervision of a
human attendan~. If a human attendant is absent from the
attendant's portion 40 o~ the machine 10, shown in
Figure 1, then the supervision assurance means 484
actuates the machine shutdown means 472. The supervision
assurance means 484 includes an attendant sensing
s~itch 488, which for example could be placed at the
chair on which the operator sits, with the swi~ch opening
when the operator is positioned in the chair. Electric
po~er source 280 connects via the power line 284, a
line 504, the switch 488, a line 50~, and a line 482 to
the machine shutdown means 472. Absence of the operator
from the chair closes the switch 488 immediately
actuating the machine interruption means 436.
To enable the supervision assurance means 4B4 to
actuate the machine shutdown means 472, these two
co.~ponents are connected in series to the power source.
Appropriate ground means 492 ground the machine shutdown
means 472.
If the operator is not in the chair, the switch 488
closes supplying power to the machine shutdown means 472.
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~323~7
It is to be noted that the switches 415 are positioned
sl~ff iciently close to the bars 141 and 142 so that any
significant touching of the members 88 and 89 and the
row 12 will activate the switches 415.
It is to be understood that a number of variations
of automatic machine shutdown means, which address the
problems described herein, can be adap~ed for use ~ith
automatic steering methods and systems, inasmuch as these
methods and systems generate displacement signals or
other indications of the presence and absencj~ o~ the
row 12.
Assuming that either of the monitoring bars 141
and 142 moves from its neutral position within the
predetermined amount of time, then the automatic machine
shu~down circuit 275 will deliver no electricity to the
operation locomotion interruption means 436. If both of
the monitoring bars 141 and 142 remai~ in their neutral
positions for the predetermined amount of ~ime, then the
displacement signal sensing switches 415 will remain
closed, power will be supplied to the interruption
means 436, and the operation and locomotion of the
machine 10 will halt.
The predetermineid amount of time should be selected
to provide prompt halting of the machine 10, assuming
that the machi~e 10 is at the end of the row 12.
Sometimes there are headlands which allow a margin of
safety at the ends of the rows 12~ ~owevrr, in other
cases irrigation ditches are close to the ends of the
rows 12. The time should not be so short that a ~.inor
hiatus in the row 12, such as a pathway, triggers a
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shutdown. In certain circumstances, then, an appropriate
ti~e is two to five seconds.
Figure 10 summarizes an embodiment of logic which
~h~ invention uses. In Fiyure 10, various triangle~
represent decisions, upon which ~che alltomatic steering
means 4 and the automatic machine shutdown means 8 act.
According to triangle 512, if there is no attendant in
the machine 10~ then the chassis 20 halts. If an
attendant is presen~, ~hen the next ~eeision represented
by triangle 51S is addressed. ~ccording to triangle 516,
if a predetermined amount of time7 which is illustrated
as two to five seconds, elapses without any contact
Gccurring with the row 12, then the chassis 20 halts. If
contact signals occur more PrequentlyJ then the logic
proceeds to an automatic steering ~tage 520. The
automatic steering stage 520 comprises a fir t branch of
logic 524 and a second branch of logic ~280 Under the
~ranch 524, there is an initial decision represented by a
triangle ~320 AccoYding to triangle 532, if the
chassis 20 i~ on cen~er, then no steering ~orrection is
~ necessary. If the chassis 20 is off to the left of
center, then ~he logic proceeds to a decision which
triangle 536 represents. If the steerable wheel 28 is
less ~han a predetermined angle, which is illustrated as
five degrees, rom straight, then the invention keeps
t~rning the steerable wheel 28 to the righ$. If the
steerable wheel 2B has rotated an angle of five degrees
from straight (meaning that the wheel 28 is at a first or
second pivot limit 211 and 212 o~ Figure S) 9 then the
wheel 2B stops pivoting. Under the second branch 528,
the logic initially decides whether the chassis 20 has
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s~eered off to the right of center as represented in
triangle 540. If it has not, then no correction is
neceSsary~ I~ it has, then the logic proceeds to another
decision shown as triangle 544. If the steerable
~heel 28 is less than five degrees from straight, then
the wheel 28 keeps pivoting to the lefta If the wheel 28
has rotated an arc of five degrees ~rom straight, then
the steerable wheel 28 stops pivoting.
In summary~ the invention senses and monitors the
position of the row 1~ with respect to the ~achine 10
~ith entirely mechanical, non-hydraulic meansD Because
it accoun~s for varia~ions in ~he thickness o plants in
the row 12, it is self-sufficient~ The inventior, also
monito~s the presence of the row to guard against
overrunning of gaps in the row. Also, it elimin2tes
steps required to correlate a corrective rotation of the
steerable wheel 28 to a quantity of steering error.
In harvesting berries, the invention steers the
chassis 20 sufficiently close to the row 12 to masimize
the retrieval of berries during berry harvesting.
From the ~oregoing, i~ is apparent that this
invention is one well adapted to attain the objects set
forth above, together with o~her advantages. It is to be
understood that various modi~ications could be ~ade to
the present invention without departing from the basic
teachings thereof.
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