Note: Descriptions are shown in the official language in which they were submitted.
CA 022~4~ 1998-11-20
TITLE: Distance Indicator SYstem for Golf
This invention relates to devices used primarily in the game of
golf. More particularly, the invention relates to a system for
measuring distances from the player to a selected target on a golf
course. Generally, the selected target is the pin flag for the
green of the hole currently being played. An alternate target
could be an nearby bunker or water hazard. While the invention
is specifically directed towards golf, it can be appreciated that
the system can by used in other fields where a user wishes to know
the distance to a specified target.
Background of the Art
Devices which enable a golfer to determine distances to
targets are known.
One device for measuring distances utilizes sonar techniques
to direct a ultrasonic or infrared signal to the pin. The device
measures the time elapsed to receive-the return signal reflected
from the pin. This device requires the golfer to aim the device
accurately to the pin, which may be difficult.
Other devices calculate distances by receiving signals from
global positioning satellites (GPS). These devices, while
accurate, are complex and relatively expensive.
CA 022~4~ 1998-11-20
US Patent No. 3,868,692 entitled ~Golf Yardage Finder" is
disclosed by Woodward et al. The device comprises a portable unit
which selectively receives different RF (Radio Frequency) signals
sent by different transmitters located on different pins. The
strength of the received signal is proportional to the distance to
the pin. Here, the transmitters for each pin are always emitting
their signals, which causes more power consumption for the
transmitters.
US Patent No. 4,136,394 entitled "Golf Yardage Indicator
System" is disclosed by Jones et al. This device utilizes bi-
directional communications between a remote unit and a target unit
located on a pln. The remote unit transmits an activation message
to the target unit. The target unit responds by emitting a
responding message to the portable unit. The remote unit measures
the elapsed time between sending the activation message and
receiving the responding message to calculate the distance to the
pin. Amongst other features, the remote unit also allows the
user to provide wind speed information which can be used by the
remote unit to indicate how far and where a shot should be aimed
to compensate for the wind. However, this invention does not
discriminate between response messages sent from different target
units which may be near each other. As such, the user will not
know what distance is being measured.
CA 022~4~ 1998-11-20
Summary of the Invention
Accordingly the present invention provides a distance
indicator system for providing the distance between a golfer and a
pin flag on a golf course. The distance indicator system
comprises a target unit associated with the p~n flag and a
portable unit used by the golfer.
The portable unit comprises a microprocessor, selection means
to select said target unit, an activator, an encoding means for
encoding a signature signal of the target unit into an initiation
signal, a transmitter for transmitting the initiation signal to
said target unit, a receiver for receiving a responding signal
from the portable unit, a decoder for decoding and extracting a
responding signature signal from said responding signal, a
processing unit for comparing the responding signature signal an
identity signal for the target unit, a distance calculation unit
which calculates a distance based on transmission characteristics
of the initiating signal and the responding signal and a display
device.
The target unit comprises a microprocessor, a receiver for
receiving initiation signals broadcasted from a portable device,
an unit to extract the signature signal from the received signals
and a processing unit for determining intended target unit from
CA 022~4~ 1998-11-20
said initiation signal. The target unit also includes an encoder
to encode a responding signature into a responding signal and a
transmitter for broadcasting the responding signal to the portable
device.
It is an aspect of this invention that the target unit and
the portable unit actively receive and transmit signals to each
other.
Many other features and advantages of this invention will be
more fully understood from the following detailed description when
taken in conjunction with the accompanying drawings.
Brief Description of the Drawings
Figure 1 is a perspective diagram illustrating a golfer using
the invention on a golf course;
Figure 2 is a illustrates one embodiment of the portable
unit;
Figure 3 illustrates one embodiment of the target unit on a
golf pin;
CA 022~4~ 1998-11-20
S
Figure 4 is a block diagram of the major functional elements
of the portable unit;
Figure 5 is a block diagram of the major functional elements
of the target unit;
Figure 6 is a timing diagram of two representative digital
signature signals for two different target units.
Figure 7 is a block diagram showing detail of the major
functional elements of another embodiment of the portable unit;
Figure 8 is a block diagram showing detail of the major
functional elements of another embodiment of the target unit;
Detailed Description of the Drawings
Figure 1 shows a typical situation where the invention may be
used. Golfer 1, standing by his ball 2, carries portable unit 5.
He is playing the hole ending at pin 3a, which has target unit 4a
mounted to its top. Nearby holes are indicated by pins 3b and
3c, which have target units 4b and 4c respectively mounted to
their tops. It can be appreciated that other target units can be
located near other significant objects, such as bunkers or water
,
CA 022~4~ 1998-11-20
- 6 -
hazards. Transmitted signals broadcasting from portable unit S
are indicated by arrows 6. A responding signal broadcasting from
target unit 4a is indicated by arrow 7a. A responding signal
broadcasting from target unit 4c is indicated by arrow 7c.
The measuring system operates by first having the portable
unit broadcast an encoded initiation signal to its intended target
unit. When the intended target unit receives the initiation
signal, it analyzes the signal and, if appropriate, send an
encoded responding message. When the portable unit receives the
responding signal, it analyzes that signal and, if appropriate,
calculates and displays the distance to the target unit.
In Figure 1, target unit 4a is the intended target for
portable unit 5. While many target units may receive initiation
signal 6, the initiation signal contains a signature signal unique
to target unit 4a. As such, if target units 4b or 4c receive
initiation signal 6, they analyze the signal and will determine
that the signature signal is not theirs. Accordingly, they will
not respond to initiation signal 6. -However, when target unit 4a
receives initiation signal 6, analyzes it and recognizes its
signature signal, it will initiate responding signal 7a.
Portable unit 5 can receive responding signals transmitted
from any target unit. However, the portable unit will only make a
distance calculation when it receives responding signal 7a, as it
CA 022~4~ 1998-11-20
is only expecting responding signal 7a. As shown in figure 1,
responding signal 7c is sent by target unit 4c and is intended to
respond to a different portable unit. While portable unit 5
receives responding signal 7c, it does not execute a distance
calculation for the hole associated with target unit 4c.
The invention described herein uses digital signatures which
are encoded and transmitted as analog signals. However, it can be
appreciated that strictly analog signals may be used as the
signatures.
Figure 2 shows one possible form of portable unit 5. While
the exact appearance of the unit may differ, it has the following
elements. Selector buttons 9 allow the user to scroll up and
scroll down through the holes in the golf course, which is
displayed in reading 12 in the display window 8. It can be
appreciated that various selector mechanisms can be used,
including dials or keypads. Once the intended hole is selected
(here, the user has selected the seventh hole), the user activates
the measuring system of the invention by pressing activation
button 10, labeled "DISTANCE". After portable unit 5 completes
communications with the target unit of the intended hole, it
calculates the distance thereto and displays the result as
distance reading 13 in display window 8. Here the calculated
distance is ~123~ yards. All communications sent and received by
portable unit 5 are transmitted and received through antenna 11.
.
CA 022~4~ 1998-11-20
- 8 -
Figure 3 shows a details of the target unit 4a. Pin 3a
functions as a conventional pin for hole 31, but also has target
unit 4a mounted on its top. All communications sent and received
by target unit 4a are processed through antenna 16.
Figure 4 shows the major functional blocks of portable unit
5. The main controlling element of portable unit 5 is
microprocessor 12. It controls all the functional elements,
performs the distance calculations and controls the display of the
results.
To use the portable unit, selector buttons 9 are used to
select the intended hole. Microprocessor 12 updates display 8 by
causing it to show the current hole selected as the user cycles
through his hole selections. Once the intended hole has been
selected, the user presses activation button 10 to initiate the
measuring system.
Referring to Figure 4, portable unit S has a list 32 which
contains information on digital signatures associated with each
target unit. Figure 6 shows representations of two digital
signatures for two different target units. Each signature is a
digital pulse of a different length. In the present embodiment,
pulse 23 has a leading edge 25, a length of duration 1, indicated
at 24, and a trailing edge 26. Pulse 27 has leading edge 28, a
CA 022~4~ 1998-11-20
length of duration 2, indicated at 29, and a trailing edge 30.
The target unit for each hole has a unique digital signature
associated with it. It can be appreciated that other digital
signatures may be used, which may be represented by a series of
unique digital "0" and "1" values.
When the portable unit is activated, Encoder/Transmitt~r 13
selects the digital signature associated with intended target unit
from list 32 and converts the signature to an analog signal. The
analog signature signal is modulated onto a radio frequency
carrier producing initiation signal 6. Thereafter, initiation
signal 6 is transmitted through antenna 11. It can be appreciated
that other wireless transmission techniques may be used, including
SONA~ or infrared signals.
Around that instant, microprocessor 12 starts an internal
timer 33. The timer is used in the distance calculation The
timer 33 is turned off when portable unit 5 receives a responding
signal from a target unit.
Figure 5 illustrates details of target unit 4a, which
receives and processes initiation signal 6. Using the signature
signal encoded in the initation signal, a target unit can
determine if a received initiation signal is intended for it. To
accomplish this, the analog signature is extracted from the
received initiation signal, then it is converted it to a digital
CA 022~4~ 1998-11-20
- 10 -
signature. The digital signature is used to determine if the
initiation signal was intended for the target unit.
Initiation signal 6 is received by target unit 4a through
antenna 16. RF receiver 18 processes the signal and sends it to
decoder 19. Decoder 19 removes the carrier frequency from
initiation signal 6, thereby leaving only the analog signature
signal. This signal is converted to its digital equivalent for
processing by the decoder. Then, microprocessor 17 compares the
resulting digital signature to the signature signal of target unit
4a. If the received signature matches the signature pulse of
target 4a, then target unit 4a knows that a portable unit is
requesting a response from it. If they do not match, target unit
will not respond to the signal.
To generate a response, encoder 21 produces the digital
signature signal for target unit 4a. This signal is then
converted to its analog signal. The preferred method of
converting the signal uses pulse width modulation techniques;
however, other digital signals can be generated by other
commercially available devices or by using other encoding
techniques. Encoder 21 then combines the analog signal with the
transmission radio frequency generated by oscillator 20, producing
responding signal 7. RF transmitter 22 and antenna 16 are used
to transmit responding signal 7. It is preferred that the same RF
used to broadcast the initiation signal is used to broadcast the
,
CA 022~4~ 1998-11-20
responding signal. However, it is possible that different radio
frequencies may be used.
Figure 4 shows details of portable unit 5, which processes
received responding signals. Responding signal 7 is received by
portable unit 5 through antenna 11. RF receiver 14 sends the
received response to decoder 15. Decoder 15 isolates the
signature signal from the responding signal, then signature to its
digital format. In this preferred embodiment, the digital
signature is a pulse. However, it can be appreciated that other
digital and analog signatures may be used to identify the target
unit associated with the responding signal.
Referring to Figures 4 and 6, when the leading edge 25 of the
pulse 23 is recognized, microprocessor 12 stops its internal timer
33. The pulse is sent to decoder 15 for signature verification.
In the present embodlment decoder 15 comprises a monostable
multivibrator. It is the length of the pulse which provides the
signature. If duration 24 matches the duration of the pulse
associated with intended target unit 4a, then encoder 15 and
microprocessor 5 will cooperate to determine that a responding
signal from the intended target unit was received. As such,
microprocessor 5 then calculates a distance based on the elapsed
time in its internal timer 33 and the frequency of the carrier
frequency. This value is displayed on display 8.
CA 022~4~ 1998-11-20
If duration 24 does not match the digital signature of the
intended target unit 4a, then the received responding signal 7 is
from another target unit. As such, portable unit 5 sends another
initiation signal 6 through antenna 11 and waits for a response.
If after several retries, either no response or responses are
received from another target unit, the portable unit cannot
calculate a distance to intended target unit 4a. In this
condition, microprocessor 12 causes an error message to be
displayed on display 8.
It can be appreciated that in another embodiment, the target
unit may generate its responding signal 7 whenever it receives any
initiation signal intended for any target unit. In this
embodiment, when the responding signal is received by each
portable unit, each portable unit must evaluate the signal to
determine if the replying target unit was the intended target
unit.
Figure 7 shows a block diagram of the elements of another
embodiment of portable unit 5. Herein, the functional components
of portable unit 5 comprise controller 31, transmitter 32, display
33, pseudo random number generators 34 and 35, transmit/receive
switch 36, antenna 37, receiver front end 38, correlator 39,
detector 40, oscillator 54, intermediate frequency box 53 and
delay circuit 41.
. . .
CA 022~4~ 1998-11-20
Figure 8 shows a block diagram of the elements of antoher
embodiment of the target unit 4. The functional components of
target unit 4 comprise controller 42, transmitter 43, pseudo
random number generator 44, transmit/receive switch 45, antenna
46, receiver front end 47, oscillator 55, correlators 48 and 49,
detectors 50 and 51 and delay lock loop control circuit 52.
Referring to Figures 7 and 8, portable unit 5 measures the
round trip propagation delay from the portable unit to the target
unit and back.
When the portable unit is activated, a high rate pseudo
random number sequence is generated by PRNG 34 and is transmitted
through transmitter 31, transmitter switch 36 and antenna 37. The
signal is encoded in spread spectrum techniques. The number
sequence is unique to the target unit being interrogated. During
this time the target unit will synchronize to this data stream.
The target unit receives the transmitted number sequence via
antenna 46, receive switch 45, front end receiver 47, correlators
48 and 49, detectors 50 and 51 and delay lock control 52. The
correlators determine whether the number sequence received is for
the unit, and if so, the signal is de-spread. The duplicated
correlators and detectors and the delay lock control provide
synchronization of the received signal. Intermediate frequency
boxes 56 and 57 along with detectors 50 and 51 determine whether
.. ..
CA 022~4~ 1998-11-20
- 14 -
the strength of the received de-spread signal is corresponds to
the correct number sequency. If so, controller 42 responds with
the same number sequence by generating the sequence through PRNG
44, then transmits it through transmitter 43, transmit switch 45
and antenna 46. Again, the signal is encoded with spread spectrum
techniques.
At the portable unit, the signal sent from the target unit is
received through antenna 37, receiver front end 38 and correlator
39. Correlator 39 determines whether the received spread signal
is for it, and if so, the signal is de-spread. Intermediate
frequency box S3 and detector 40 check the level of the received
signal and if appropriate notify controller 31 that a signal has
been received. Thereafter, the controller will measure the time
delay between the number sequence originally sent and the received
number sequence. This time delay is converted to indicate the
distance between the portable unit and the target unit. The
distance is shown on display 33.
To avoid timing ambiguities due to multipath propagation of
signals, delay circuit 41 spreads the transmission of the number
sequence. To identify the incident signal, the direction of
search is in the direction of increasing delay, thereby m;nimi zing
the probability of locking onto a reflected ray.
.
CA 022~4~ 1998-11-20
- 15 -
It can be appreciated that in another embodiment, the
distance calculation may be based on non-temporal means, such as
the strength of the responding signal received by the portable
unit.
While specific embodiments of the present invention have been
illustrated herein, it will be understood that variations and
modifications may be effected without departing from the spirit
and scope of the invention.
