Electronic speed measuring device particularly useful as a jogging computer

An electronic device particularly useful as a jogging computer comprises presetting means for presetting the size of the user's step, an inertia sensor sensing each step, a central clock, and a microprocessor computing the user's speed and distance travelled, and displaying same on an electronic display. The described device further includes a pacer which produces a tone at a preselected rate to aid the jogger in pacing himself. A second embodiment of the invention is described for attachment to a bicycle for measuring speed and distance travelled of the bicycle.

BACKGROUND OF THE INVENTION 
The invention relates to an electronic speed measuring device, and 
particularly to a portable, low-cost, highly-accurate device which can be 
conveniently carried by the object whose speed is being measured. The 
invention is especially useful as a jogging computer and is therefore 
described below with respect to this application, but it could also be 
used for other applications as will also be described below. 
Mechanical type jogging computers are known in which the user first presets 
the device according to his step size, and later when jogging, the 
computer senses each step by a mechanical type sensor and computes the 
distance travelled. However, this known type of jogging computer is quite 
imprecise in its computations of distance. Moreover, it does not compute 
speed or peform other functions which would be helpful to a jogger. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an electronic speed 
measuring device which is particularly useful as a jogging computer, 
provides very accurate measurements, and is capable of performing a number 
of other functions. One particularly important function capable of being 
performed by the electronic device of the present invention is a pacer 
function, in which the device emits periodic tones at a preselected rate 
to aid the jogger in pacing himself. 
According to a broad aspect of the present invention, there is provided an 
electronic device for measuring distance traversed by a body in motion per 
unit time comprising a housing including presetting means for presetting a 
distance constant corresponding to the distance per increment of the 
motion, and a sensor sensing these increments of motion and outputting a 
sensor signal for each. The device further includes an electronic display, 
and an electronic data processor having a central clock measuring time in 
a real-time manner, means for storing the preset distance constant, means 
for computing the time interval between successive sensor signals, means 
for multiplying the latter time interval by the stored distance constant 
to produce a measurement of speed, and means for feeding the latter 
measurement to the electronic display. 
In the preferred embodiment of the invention described below, the 
electronic data processor further includes means for multiplying the total 
number of sensor signals by the inputted distance constant to produce a 
measurement of distance travelled, and for displaying that latter 
measurement in the electronic display. 
According to a further important feature of the invention, the presetting 
means also includes means for presetting pacer-rate constant corresponding 
to a predetermined number of increments of motion per unit time. A tone 
generator carried by the housing is actuated to sound an audible tone for 
each of the predetermined number of increments of motion per unit time, 
and thereby to pace the user. 
One described embodiment is a jogging computer, wherein the 
distance-presetting means is used for presetting information corresponding 
to the size of the user's step when jogging. This embodiment may include a 
clip for attachment to his wrist. A second embodiment of the invention is 
described wherein the information to be preset corresponds to the diameter 
of the wheel in a wheeled vehicle, such as a bicycle, whereby the device 
may be used as a vehicle speedometer. 
Further features and advantages of the invention will be apparent from the 
description below.

DESCRIPTION OF PREFERRED EMBODIMENTS 
General Construction 
FIG. 1 illustrates a jogging computer of small compact size adapted to be 
conveniently carried by the user to measure and display his jogging speed 
and also the total distance travelled over any preselected time interval. 
The illustrated device can also be used as a pacer for emitting a tone 
signal or "beep" at preselectable rates to aid the jogger in pacing 
himself. Further, the illustrated device can be used also as a stop watch 
to time the jogger, and as a delay alarm to sound a signal after a 
preselected time or distance 
The device illustrated in FIG. 1 comprises a housing generally designated 
2, constituted of a front section 4 closed by a back panel 6, e.g. by the 
use of fasteners 8 or by a snap fit such as in pocket-size transistor 
radios, calculators, hand-held electronic games, and the like. A printed 
circuit board 10 carrying the electronic elements of the device, as will 
be described more particularly below, is enclosed within the housing, 
these elements being made accessible by removing the back panel 6. 
The front housing section 4 is formed with an elongated window 12 extending 
across its top wall, and with a keyboard of four push-buttons supported on 
its front wall. These four push-buttons include Reset button RB, 
Start/Stop button SSB, and two Data buttons B.sub.1 and B.sub.2 for 
presetting information into the device. The front housing section 4 is 
further formed with a plurality of openings 14 serving as a grill for a 
speaker disposed within the housing. The back panel 6 includes a belt-clip 
16 for attachment to the belt of the user. 
The printed circuit board 10 within the housing carries all the electronic 
components, including a microprocessor 20 and an electronic display 22, 
which may be the LCD (Liquid-Crystal-Device) or the LED 
(Light-Emitting-Diode) type. The electronic display 22 is secured to the 
upper end of the printed circuit board 10 at right angles thereto so as to 
align itself with window 12 of the front housing section 4 when the device 
is assembled. 
A speaker 24 is carried at the lower end of the printed circuit board and 
is aligned with the speaker grill 14 of the front housing section when the 
device is assembled. The lower end of the printed circuit board 10 also 
includes a battery connector 26 for connection to a battery 28 to be 
disposed in a suitable compartment provided in the front housing section. 
Printed circuit board 10 further carries a sensor S for sensing the 
increments of motion and for outputting a sensor signal for each 
increment. When the device is used as a jogger computer, these increments 
of motion would be the steps of the jogger. Sensor S is of the inertia 
type and comprises a cantilever-mounted leaf spring 30 normally biassed 
out of engagement with a fixed stop 32, but displaceable to engage same by 
inertia with each step of the jogger. Both the leaf spring 30 and the stop 
32 are of metal, and come into contact to complete an electrical circuit 
with each step made by the jogger. Each completion of the electrical 
circuit thus produces a sensor signal which is fed to the microprocessor 
20 for processing in the manner to be described below. 
The jogging computer illustrated in FIG. 1 can perform the following 
functions: 
1. compute and display jogging speed, 
2. compute and display distance travelled; 
3. display running time (stop-watch), 
4. sound a pacing buzzer per a set frequency, 
5. sound a pacing buzzer per a calculated frequency, and 
6. sound a delay alarm per a preset time or distance 
Each of these functions will be described more particularly below. 
Functional Logic 
FIG. 2 is a block diagram schematically illustrating the functional logic 
of the microprocessor 20 in the device of FIG. 1, including its inputs and 
outputs. Thus, its inputs include the Reset button RB, the Start/Stop 
button SSB, the Data buttons B.sub.1, B.sub.2, and the inertia sensor S 
sensing each step made by the jogger. The outputs of microprocessor 20 
include the electronic display 22 and the speaker 24. 
The functional logic of microprocessor 20, as illustrated in FIG. 2, 
includes a Preprogrammed Control Unit PCU which receives its inputs from 
the Reset button RB, the Start/Stop button SSB, the Data buttons B.sub.1, 
B.sub.2 and the sensor S. Information inputted by the Data buttons 
B.sub.1, B.sub.2 may also be selectively fed to a Step Size Storage 
circuitry SSC, a Pacer Data Storage circuitry PDC, a Delay Alarm Storage 
circuitry DAS, or a Display Select circuitry DS, all as selectively 
controlled by the Preprogrammed Control Unit PCU. 
Circuitry SSC stores the preset size (inputted in the Metric system or 
English system as described below) of the user's step while jogging. 
Circuitry PDS stores the preset information which determines the frequency 
of the "beeps" to be sounded by the speaker 24. The user has two options 
for inputting this information. That is, he may input either (1) a 
predetermined number of beeps per minute, or (2) the total distance of a 
"run" and the total time to traverse same, in which case the device will 
calculate the appropriate number of beeps per minute. 
Circuitry DAS stores the time period after depressing the Start/Stop button 
SSB that an alarm will be actuated. 
Microprocessor 20 further includes a central clock CC which measures time 
in a real-time manner and controls thereby various calculations and 
operations, as will be described more particularly below. 
The circuitry included within microprocessor 20 for performing calculating 
functions includes Speed Calculation circuitry SC receiving information 
from the Step Size Storage circuitry SSS and controlled by the Central 
Clock CC, the Sensor S, and the Preprogrammed Control Unit PCU. Distance 
travelled calculations are performed by circuitry DTC which also receives 
information from the Step Size Storage circuitry SSS and is controlled by 
the Sensor S and the Preprogrammed Control Unit PCU. Pacer calculations 
are performed by circuitry PC which receives information from the Pacer 
Data Storage circuitry PDC and the Step Size Storage circuitry SSS, and is 
controlled by the Central Clock CC and the Preprogrammed Control Unit PCU. 
Microprocessor 20 further includes Delay Alarm Comparator circuitry DAC 
which receives information from the Delay Alarm Storage circuitry DAS and 
is controlled by the Central Clock CC and the Preprogrammed Control Unit 
PCU. 
Finally, the microprocessor 20 includes Tone Generator circuitry TG and 
Display Select circuitry DS. The Tone Generator circuitry TG drives the 
speaker 24 according to a predetermined pace, either preselected or 
calculated in Pacer Calculations circuitry PC as controlled by the 
Preprogrammed Control Unit PCU, or according to the delay alarm data 
stored in DAS which is compared with the time registered in Central Clock 
CC via the Delay Alarm Comparator DAC. The Display Select circuitry DS 
selectively feeds the electronic display 22 with the information from the 
Data buttons B.sub.1, B.sub.2, the Distance Travelled Calculations 
circuitry DTC, or the Speed Calculation circuitry SC, as controlled by the 
Central Clock CC and the Preprogrammed Control Unit PCU. 
Presetting 
The device illustrated in FIGS. 1 and 2 is preset according to the step 
size, the measuring system (Metric or English), the desired pacer rate of 
beeps per minute or the data (running distance and running time) from 
which the pacer rate is to be calculated, and the delay alarm This is done 
in the following manner: 
First, Reset key RB is depressed, resetting the circuitries within the 
microprocessor, at which time the display 22 will show "000 000. " 
Preferably, the microprocessor is programmed so that only the measurements 
made by the device are reset, and not the originally preset information, 
which latter information is reset only if, where, and when needed, in the 
same manner as it is preset in the setting cycle. 
To start the setting cycle, Data button B.sub.2 is depressed at which time 
the display will show "100 000," indicating that the device is ready for 
the first setting data. 
The first setting data is the step size of the jogger using the device. His 
step size is preset in the form of a two-digit figure. First, he depresses 
Data button B.sub.2, whereupon the extreme right digit of the electronic 
display 22 starts to slowly count-up. When the correct figure 
corresponding to the rightmost digit of his step size appears, the user 
releases Data button B.sub.2, and depresses Data button B.sub.1 to 
register that figure in the Step Size Storage circuitry SSS. The next 
digit of the jogger's step size is set in the same manner and when Data 
button B.sub.1 is depressed for registering this second digit, the display 
22 shows "200 000," and the device is now ready for the second setting. 
The second setting relates to the measuring system desired, i.e. Metric or 
English. To effect this setting, Data button B.sub.2 is depressed, 
whereupon the rightmost digit of display 22 will alternately show "1" 
indicating the metric system, and "2" indicating the English system. 
Button B.sub.2 is released when the desired system is shown, and then 
button B.sub.1 is depressed to enter this into the Step Size Storage 
circuitry SSS. Display 22 will now show "300 000." 
The third setting concerns the selected pacer rate, namely the rate that 
the Tone Generator TG will be actuated to drive speaker 24 to produce 
audible sounds or "beeps." The selected number of "beeps" per minute is 
preset in three digits, each as in the step size operation. That is, for 
each digit of the selected rate, Data button B.sub.2 is despressed until 
that digit is shown in the display 22, and then Data buttons B.sub.1 is 
depressed for registering that digit in the Pacer Data Storage circuitry 
PDC. When the third digit of the pacer rate has thus been stored by 
depressing Data button B.sub.1, the device is switched to the fourth 
setting, and the display now shows "400 000." 
The fourth setting is used for presetting the device according to the 
second pacer option, namely the beeps per second required to traverse a 
specified total distance in a specified total time. Each digit of the 
total distance is set in the same manner as in the first setting, by first 
depressing the Data button B.sub.2 until the appropriate number appears in 
the display, and then registering that number in the Pacer Data Storage 
circuitry PDC by depressing button B.sub.1. If the second setting selected 
the Metric system, the inputted distance would be in meters, and if it 
selected the English system, the inputted distance would be in yards. Five 
digits are allotted for the total distance. After the fifth digit has been 
set, pressing button B.sub.1 clears the display, except for the extreme 
right digit which will still show "4" The device is now ready for setting 
the seconds in three digits, which is done in the same manner. When that 
setting is completed and button B.sub.1 is depressed, the display shows 
"500 000," and the device is now ready for the fifth setting. 
Only one pacer option may be used, i.e. that of the third or fourth 
setting. If that of the third setting is desired, the fourth setting is 
preset to "0," and if that of the fourth setting is desired, the third 
setting is preset to "0." If neither pacer option is desired (i.e. no 
pacer function), both settings are set to "0." 
The fifth setting concerns the delay alarm, and selects the specific time 
in hours, minutes and seconds that the alarm is to be sounded. The actual 
setting is made by the use of the Data keys B.sub.1 and B.sub.2 in the 
same manner as described with respect to the first setting, the first two 
digits from the right indicating seconds, the next two digits indicating 
minutes, and the fifth digit indicating hours. The second and fourth 
digits only run from "0" to "5." This information is stored in the Delay 
Alarm Storage circuitry DAS. 
After the fifth setting has been completed, the display 22 returns to its 
normal setting, i.e. it simultaneously displays speed in the three right 
digits, and distance in the three left digits. 
Operations 
Once the above setting have been made, the Start/Stop button SSB may be 
depressed whenever it is desired to start the measuring operations during 
jogging, whereupon the sensor S senses each jogger step and the Central 
Clock CC measures time in a real timer manner. By depressing button 
B.sub.1, the display is switched to alternate between a Speed/Distance 
Mode displaying the speed in the three right digits and the distance in 
the three left digits, and a Stop Watch Mode displaying the actual running 
time. 
When operating in the Speed/Distance Mode, the device measures the speed of 
the jogger by multiplying the step size as preset in the Step Size Storage 
circuitry SSS, by the time interval between steps, i.e. between two 
successive input signals from the sensor S. The device measures the 
distance travelled by multiplying the step size from the Step Size Storage 
circuitry SSS by the total number of steps, i.e. the total number of 
signals received from the sensor S. 
Actually, the speed is continuously computed and displayed as a weighted 
average, rather than as an instantaneous value. For example, the speed is 
continuously computed by multiplying the previous speed computation by a 
first predetermined weighted number "n" (e.g. "9"), adding the 
instantaneous speed for the respective step multiplied by another weighted 
number "M" (e.g. "1"), and then dividing the result by "n+m" (i.e. "10"). 
Thus, each step will have only a 10%, rather than a 100%, influence on the 
speed computation displayed by the device at any instant. This prevents 
rapid fluctuations in the speed read-out caused by slight variations in 
the instantaneous speed of the jogger during each step. It will be 
appreciated that the microprocessor, particularly its pre-programmed 
control unit circuitry PCU, can be programmed in known manners to produce 
the above weighted average speed computation, or an instantaneous speed, 
as may be desired. 
The stop-watch function is performed by the Control Clock CC which reads 
out to the display 22 the time in hours, minutes, seconds and 1/10 seconds 
whenever Data button B.sub.1 is depressed which, as described above, 
causes the running time to be displayed alternately with the 
speed/distance. 
If the device is to be used only in the Stop-Watch Mode, Reset button RB 
may be depressed, and then button B.sub.1 (rather than button B.sub.2) may 
be depressed, whereupon the above described setting functions are 
by-passed. The device first displays "000 000" and thereafter operates as 
a stop-watch displaying the running time, until the Start/Stop button SSB 
is again depressed. 
The function of energizing the pacing buzzer is performed by the Tone 
Generator circuitry TG which drives the speaker 24 in accordance with 
either the present rate, or the required rate for a preset distance and 
running time as stored in the pacer Storage Circuitry PDC and processed by 
the Pacer Calculations circuitry PC. In the latter case, the Pacer 
Calculations circuitry calculates its own rate by dividing the distance to 
be run by the total number of seconds in which it is to be run, and then 
dividing this by the step size, to produce the appropriate beep rate. 
The delay alarm function involves the sounding of a delay alarm at a preset 
time. This function is performed by the Delay Alarm Comparator circuits 
DAC which compares the preset time stored in the Delay Alarm Storage 
circuitry DAS with the Central Clock CC, to actuate the Tone Generator TG 
(e.g., continuously for five seconds) when the preset time has arrived. 
The device may also be programmed to sound the delay alarm after a preset 
distance has been traversed. In this case, the Delay Alarm Comparator 
circuit DAC would compare the preset distance stored in the Delay Alarm 
Storage circuitry DAS with the information in the Distance Travelled 
Calculations circuitry DTC to actuate the Tone Generator TG (e.g. 
continuously for five seconds) when the preset distance has been 
traversed. 
It will be appreciated that commercially-available microprocessors such as 
are known and used for example in the electronic hand-held games, may be 
programmed according to known techniques to perform all of the above 
functions. For example, one micro-processor that may be used is TMS 1100, 
C-MOS version available from Texas Instruments Corp., whose construction, 
operation, and method of programming are described in the book titled 
"Programmer's Reference manual TMS 1000 Series MOS/LSI, One-Chip 
Microcomputer," Copyright 1975 by Texas Instruments Corporation. 
FIG. 3 illustrates a modification of the invention of FIGS. 1 and 2, 
wherein the housing, therein designated 102, is secured to a wrist band 
116 for attachment to the user's wrist, thereby simultaneously digital 
electronic wrist watch. In such an arrangement, the electronic display, 
therein designated 122, would occupy the front wall of the housing 102. In 
addition, the four push-buttons for presetting the information and 
controlling the modes of operation, would preferably occupy the four 
corners of the housing, as indicated by Reset button RB', Start/Stop 
button SSB' and Data buttons B.sub.1 ', B.sub.2 '. The structure and 
operation of the device illustrated in FIG. 3 would otherwise be the same 
as described above with respect to FIGS. 1 and 2. 
FIG. 4 illustrates the device embodied as a speedometer and mileage 
indicator for a wheeled vehicle, namely a bicycle. For this purpose, the 
housing, therein designated 202, would be attached in any suitable manner 
to the bicycle, as by the use of a clamp 216 securing same to the bicycle 
handle bars. In addition, the sensor in this case would sense each 
revolution of the bicycle wheel, rather than each step of the jogger, and 
therefore the information preset into the Step Size Storage circuitry SSS 
would correspond to the circumference (or diameter) of the bicycle wheel. 
The sensor, therein designated S", could be any known sensor for sensing 
each rotation of the wheel, for example a probe of the electromagnetic or 
capacitance type fixed to the frame and adapted to sense a magnetic or 
electrically-conductive element carried by the bicycle wheel during each 
rotation of the wheel. When the device is embodied as a speedometer for a 
bicycle, the display unit 122 would preferably occupy the front or upper 
wall of the housing, and the push button, namely Reset button RB", 
Sart/Stop button SSB" and the Data buttons B.sub.1" and B.sub.2" , would 
preferably be disposed above the display unit 122. 
While the invention has been described with respect to several preferred 
embodiments, it will be appreciated that many other variations, 
modifications and applications of the invention may be made.