GB1598694A - Meter systems - Google Patents

Description

(54) METER SYSTEMS (71) We, SAMUEL ANTHONY NIXON, of 20, Central Avenue, Sale, M33 4JA, KENNETH FLETCHER, of 4 North Park Road, Bramhall, Chesire SK7 3JR, FREDERICK JAMES SWIFT, of 7 Melverley Drive, Leigh, Lancashire WN7 2HZ, JOHN AINSCOUGH of 551 Darwen Road, Bromley Cross, Bolton, Lancashire BL7 9RT, and STANLEY WILLIAM STRETTON of The Corner Shoppe, Chelford, Macclesfield, Cheshire, SKI I 9AH, all British subjects, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a meter system for use with a wheeled vehicle for measuring and displaying information related to rotation of a wheel or wheels of the vehicle.

The invention is particularly although not exclusively concerned with such a meter system which may used as a taximeter or as a test device for checking existing taximeters.

A known form of taximeter is mechanically operated in synchronism with rotation of wheels of the taxi in which it is installed and produces a digital read-out of a fare determined by the wheel rotation and also by three different pre-set conversion factors relating to different speed ranges and different distance ranges. Such taximeters are disadvantageous in that they may be expensive to manufacture having regard to the necessity of ensuring good accuracy, good reliability and ready adjustability to accommodate changes in the conversion factors.

Further it is necessary or desirable to check the operation of installed taximeters from time to time and this is customarily done by checking the read-out of the meter in a taxi after the taxi has been driven in a predetermined manner along a predetermined test course. This checking procedure is disadvantageous in that it is inconvenient, time-consuming and may be inaccurate.

An object of the present invention is to provide a meter system which can be adapted for use as a taximeter or as a test device for checking a taximeter and which when so used can overcome or at least appreciably reduce the above mentioned disadvantages.

According to the invention therefore there is provided a meter system for use with a wheeled vehicle, for measuring and displaying information related to rotation of a road wheel or wheels of the vehicle, comprising an electrical transducer system which is adapted to be mechanically coupled to said vehicle wheel or wheels so that in use such system is operable to produce an electrical output in dependence on wheel rotation, an electronic programmed computing system including a central sequential processing unit and memory means, said computing system being connected to said transducer system so as to be operable in use to produce an electrical output obtained by processing said transducer system output with a predetermined conversion factor or factors in dependence on the programming of said computer system and a display device connected to said computing device and operable to produce a display or read-out indicative of the said computer system output.

With this arrangement it will be appreciated that the use of a transducer system in conjunction with electronic circuitry enables great accuracy and reliability to be achieved with relatively small manufacturing expenditure. Further, it is possible to accommodate ready adjustment of said computing system to allow for changes in said conversion factor or factors in a simple and inexpensive manner.

Said computing system output may be representative of a linear distance. Preferably, said computing system is also operable in use to produce a further output which is obtained by processing an output other than from said transducer system with a further respective conversion factor or factors, said display device also being operable to produce a display or read-out indicative of such further output. In particular, the or one such other output which is processed may constitute the output of timing device, the corresponding output of the computing system being representative of an elapsed time.

The meter system of the invention is particularly suitable for use as a taximeter and for such use the transducer sytem may be mechanically coupled directly or indirectly to a road wheel or wheels of the vehicle or to an appropriate position in the drive transmission and the computing system may be set to operate in accordance with an appropriate conversion factor or factors for converting wheel rotation into a distanceand/or time-based monetary value or fare, the display device being arranged to produce an appropriate display such as a digital readout of said value or fare.

The meter system of the invention is also particularly suitable as a test device for use in calibrating or checking the operation of an existing installed taximeter and in this case the meter system may be arranged as described in the preceding paragraph in parallel with the existing taximeter and preferably with the coupling between the transducer system and the vehicle wheel or wheels being of a temporary, detachable nature. With this arrangement, the read-out of the meter system can be compared with the read-out of the installed taximeter after the taxi has been driven in a predetermined manner through a perdetermined distance.Alternatively, and preferably, however, said read-outs may be compared after such driving of the vehicle has been simulated with the vehicle at a standstill by appropriate rotation of a wheel or wheels of the vehicle whilst such wheel or wheels are in contact with a moving or movable surface such as a roller, endless belt or the like, or are not in contact with any surface. Where a simulated driving procedure is adopted, the transducer system may be applied detachably to a wheel or wheels or drive transmission part of the vehicle, such wheel or wheels or drive transmission part being appropriately modified on a temporary or permanent basis to permit this, or the transducer system may be applied to a movable surface as aforesaid in drive relationship with the wheel or wheels.In a particularly preferred embodiment, the transducer system is applied to rotatably mounted rollers on which wheels of the vehicle can rotate whilst the vehicle is at a standstill.

With regard to the nature of the transducer system of the meter system of the present invention, this may take any suitable form but preferably is of an electromagnetic nature for example involving a transducer for example comprising a coil which is fixed alongside a movable member having portions of magnetic or magnetised material whereby electrical pulses are produced as said portions move past the transducer.

Alternatively, a transducer system which involves a light source and light sensitive device or which involves engagement between electrical contacts or any suitable form of system may be employed.

When used for checking taximeters as described above, the meter system may produce a read-out representative of a fare for comparison with the taximeter read-out.

Alternatively or additionally, the meter system may produce a read-out representative of distance and/or time whereby the distance and/or time intervals at which the taximeter read-out changes can be checked. Most preferably, said computing system is arranged to follow a sequence of test operations at least some of which correspond to production of-outputs by said computing system which are functions of different outputs which are processed and/or different conversion factors. A switch may be provided for advancing the meter system from one said test operation to the next said test operation in the sequence. Such switch may be a hand switch for example in the form of a press-button.

The computer system incorporates a central sequential processing unit such as a microprocessor and this may be programmed with any suitable memory means to allow for the conversion factor or factors. As mentioned above a switch may be provided for controlling the checking procedure. Alternatively, or additionally, however initiation and termination or at least termination of the checking procedure or of an individual test operation of said procedure may be controlled on an automatic basis, for example on a time basis or in synchronism with an appropriate mechanism controlling rotation of the vehicle wheel or wheels.

The display device may be adapted to produce the said display or read-out indicative of the computing system output on a continuous instantaneous basis. Alternatively provision may be made for selecting for production of a pertaining display, the or any one of a plurality of computing system outputs as and when desired. Also, recording means may be provided whereby an output of the computing system can be recorded for subsequent recall and production of a pertaining display.

The display device may comprise one or more digitial read-out devices and/or a printing device and/or any other suitable device.

Whilst the meter system of the invention is particularly suitable for use as a taximeter or for checking taximeters, it is to be understood that the invention is not intended to be restricted to such applications and the meter system may be used alternatively or additionally for any other suitable purpose, for example, for checking vehicle speedometers.

The invention will now be described further by way of example only and with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic representation of one form of a meter system according to the invention; Figs. 2 and 3 are front and rear perspective views of a housing unit of the meter system; and Fig. 4 is a flow diagram illustrating the mode of operation of the system.

The meter system is for use in checking a taxi fare meter and comprises a transducer system 1 applied to two pairs of rollers 2, 3 (the rollers 2 being linked) which are mounted in parallel spaced apart relationship at ground level such that the taxi can be positioned with its rear wheels resting on and between the rollers 2, 3 whereby the rear wheels can be rotated by the taxi engine whilst the taxi is at a standstill. Locking means (not shown) is provided for locking at least one of the pairs of rollers 2, 3 in at least one direction of rotation thereof so that the taxi can be driven off the rollers as and when desired.

One pair of rollers 3 has a disc 4 connected thereto and this disc 4 is arranged to rotate with such pair of rollers 3 as they are rotated by frictional engagement with the driven vehicle wheels.

The disc 4 forms part of said transducer system and has portions of magnetic material disposed at equally spaced positions circumferentially around the disc. Alongside the disc 4 there is fixed an electomagnetic transducer 5 which is connected via an electrical lead 6 to a shaper circuit 7 which produces a series of like equally spaced electrical pulses as the magnetic portions on the disc 4 move past the transducer 5.

The output of the shaper circuit 7 is connected via an interface unit 8 to a central sequential processing unit in the form of a microprocessor device (MPU) 9 which also has connected thereto usual auxiliary devices including a memory means or programming device in the form of a read-only memory (ROM) 10 and a recording means in the form of a random-access memory (RAM) 11 and a clock circuit 12, and a reset switch 13 (via debounce circuitry 18).

Also connected to the interface unit 8 are: a binary to decimal converter (BCD) recall switch 14, a hand switch 15, a 7-segment digital display device 16 and a number of BCD switches 17. The reset and hand switches 13 and 15 are connected to the MPU 9 and interface unit 8 via usual debounce circuitry 18, the display device 16 is connected to the interface unit 8 via usual drive circuitry 19, and the BCD switches 14, 17 are connected to the interface unit 8 via usual multiplexing circuitry 20. The clock 12 which provides timing pulses for the operation of the microprocessor 9 is also connected to a divider 21 to give timing pulses of lower frequency, say at one second intervals, and the output of the divider 21 is connected to the interface unit 8.

As shown in Figures 2 and 3, the electronic circuitry so far described is mounted within a housing 22. The display device 16 which has two portions 16a, 16b is mounted at a front wall 23 of the housing, as also are four of the BCD switches 17a, the recall switch 14, the reset switch 13, and a main power on/off switch 24. Eight other of said BCD switches 17b are mounted at a back wall 25 of the housing, as also is a mains power input socket 26.

The transducer lead 6 can be connected to the circuitry in the housing 22 via engagement of a plug on the end of the lead 6 with a socket 27 at the back wall 25 of the housing.

Similar, the hand switch 15 has a lead 28 terminating in a plug which is engageable with a socket 29 at the front wall of the housing 22.

In use, the rear wheels of the taxi resting on the rollers 2, 3 are set in motion and at the same time the taximeter in the taxi is set in operation and operation of the meter system is initiated by actuation of the hand switch 15.

As the rollers 2, 3 rotate, impulses are fed to the interface unit 8 from the transducer system 1. The microprocessor 9 is programmed by the ROM device 10 so as to be capable of converting a count of such impulses into a linear distance. The microprocessor 9 is also programmed so as to be capable of converting a count of impulses from the divider 21 into a time indication.

Prior to commencement of the checking procedure, the meter system is pre-set with a desired sequence of test operations, such operations being selected from: conversion of impulses counted during one test operation into a linear distance; conversion of impulses counted since initiation of overall checking procedure into a linear distance; conversion of impulses counted during one test operation into an elapsed time; conversion of impulses counted since initiation of overall checking procedure into an elapsed time.

These possible test operations are identified by code numbers 1 to 4 and appropriate ones of the eight BCD switches 17b are adjusted to display the appropriate code numbers in accordance with a desired sequence of up to eight test operations. Any remaining one of the eight BCD switches 17b is adjusted to code "0" which corresponds to termination of the test sequence. If all switches are set to test operations, the sequence terminates after the eighth. Such adjustment of the switches 17b feeds appropriate signals to the interface unti 8 to effect setting of the meter system such that the processor 9 will perform the appropriate time or distance conversion during each test operation. The meter system is advanced from one test operation to the next in the preselected sequence by operation of the hand switch 15.Whenever the hand switch is operated the current test operation ceases and the next successive test operation commences.

The hand switch 15 is operated in synchronism with indexing of the taximeter so that the duration of each test operation coincides with a whole number of fare indexations of the fare meter and so that at any instant the applicable test operation having regard to the pre-selected sequence is of a kind corresponding to the basis used by the fare meter at that instant for computing the fare.

Thus, there may be a speed limit say four m.p.h., below which the taximeter assesses the fare on a time-related basis and accordingly the taxi wheels may be driven at a speed corresponding to a road speed of less than four m.p.h., or may be brought to rest, during a test operation in which the meter system effects a time-based conversion.

Above such lower speed limit the taximeter may assess the fare on a distancerelated basis and accordingly, the meter system may perform a distance-based conversion in a test operation during which the taxi wheels are driven at a speed corresponding to a road speed above such speed limit.

After elapse of a predetermined time and/or a predetermined distance from commencement of a journey the taximeter may assess the fare at a different rate, and accordingly the meter system may perform a time- or distance-based conversion in relation to the commencement of the overall checking procedure whilst the taxi wheels are driven in a manner corresponding to elapse of more than said predetermined time or distance.

During a test operation, a 5-digit part 16a of said display device 16 gives a continually updated display of the time or distance being computed by the meter system. This can be compared with the requirements for the taximeter. That is, indexing of the taximeter is required to occur at specified time or distance intervals and it can be observed as to whether or not the displayed time or distance at indexing of the taximeter is the same as, or within acceptable limits of. the required time or distance.

Operation of the hand switch 15 to change test operations may be effected in synchronism with meter indexing by a person watching the meter. If desired however, in place of the hand switch there may be an automatic switching device which, for example, responds optically to change in the displayed fare on the taximeter, such switching device being detachably mounted, in use, on or adjacent the outside of the meter. It is also possible to incorporate a switching device in the taximeter and to provide the taximeter with a socket whereby such switching device can be connected directly to the meter system.

As the test operation is changed by operation of the hand switch, the time or distance display is cleared and a fresh display produced. A record of such cleared displays is however stored in the RAM device 11 can can be recalled and displayed subsequently by operation of the BCD recall switch 14.

Such switch is set to show a code number (1 to 8) corresponding to the test operation to be recalled. The display device 16 incorporates a further one-digit portion 1 6b on which is displayed a number (1 to 8) identifying which test operation in the predetermined series of test operations is being performed or recalled.

The conversion of rotations of the disc 4 into distance will, of course depend on the diameter of the tyres on the taxi wheels in an operative condition. The meter system may be calibrated prior to commencement of a checking procedure in relation to the kind and state of wear of the tyres on the taxi being checked. In this respect, an appropriate number is pre-selected with the four BCD switches 17a and such number is utilised by the meter system to modify distance-conversion operations. The appropriate number will be selected by an operator for the particular tyres from a chart or table of precalculated such numbers.

A flow chart indicating the mode of operation of the meter system is shown in Fig. 4. As can be seen an interrupt routine is utilised which gives rise to indexing of the display for each interrupting time pulse derived from the divider 21 during a timing operation and for each interrupting unit of distance derived from the transducer system 1 during a distance calculating operation.

The embodiment described above provides a simple, reliable and versatile means of checking the operation of taximeters. Also it will be appreciated that, in so far as the meter system compares with the fare computations of a taximeter with test data obtained from the taxi wheels, the meter system can respond not only to malfunctioning of the meter but also to malfunctioning of the interconnection of the meter with the taxi wheels. Therefore effectively the system tests the entire combination of taximeter and vehicle.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only. Thus, for example, the meter system may additionally or alternatively compute factors other than distance and time, for example the system may compute the fare. Similarly provision may be made for providing data additional or alternative to the tyre data and test operation sequence data, for example fare rates. Furthers if desired, the meter system may be provided with a print-out.

Still further, the meter system is not limited in use to the checking of taximeters but may be used for checking vehicle speedometers or odometers or for any other suitable purpose.

Still further, it is possible to use two meter systems according to the invention respectively as a taximeter and as a meter for checking such taximeter in which case it is also possible to provide an interactive connection between the two meter systems whereby any detected error can be automatically corrected.

WHAT WE CLAIM IS: 1. A meter system for use with a wheeled vehicle, for measuring and displaying information related to rotation of a road wheel or wheels of the vehicle, comprising an electrical transducer system which is adapted to be mechanically coupled to said vehicle wheel or wheels so that in use such system is operable to produce an electrical output in dependence on wheel rotation, an electronic programmed computing system including a central sequential processing unit and memory means, said computing system being connected to said transducer system so as to be operable in use to produce an electrical output obtained by processing said transducer system output with a predetermined conversion factor or factors in dependence on the programming of said computer system, and a display device connected to said computing device and operable to produce a display or read-out indicative of the said computer system output.

2. A meter system according to claim 1, which is a taximeter, said computer system being programmed for conversion of said transducer system output into an output representative of a distance- and/or timebased monetary value or fare.

3. A meter system according to claim 1, for use in calibrating an instrument such as a taximeter of said wheeled vehicle, said computing system being programmed for conversion of said transducer system output into an output representative of a linear distance.

4. A meter system according to claim 1 or 2, for use in calibrating an instrument such as a taximeter of said wheeled vehicle, wherein said computing system is also operable in use to produce a further output which is obtained by processing an output other than from said transducer system with a further respective conversion factor or factors, said display device also being operable to produce a display or read-out indicative of such further output.

5. A meter system according to claim 4, further including a timing device and wherein the or one such other output which is processed constitutes the output of said timing device, the corresponding said further output of the computing system being representative of an elapsed time.

6. A meter system according to claim 4, wherein the timing device is arranged to produce regularly spaced timing pulses and said computing system is programmed for counting same to produce said elapsed time output.

7. A meter system according to any one of claims 1 and 3 to 6, for use in calibrating an instrument such as a taximeter of said wheeled vehicle and wherein said computing system is programmed to follow a sequence of test operations at least some of which correspond to production of outputs by said computing system which are functions of different outputs which are processed and/or different conversion factors.

8. A meter system according to claim 7, wherein a switch is provided for advancing the meter system from one said test operation to the next said test operation in the sequence.

9. A meter system according to claim 8, wherein said switch is a hand switch.

10. A meter system according to any one of claims 7 to 9, wherein recording means is provided for recording the output of the computing system at the end of a test operation, and recall means is provided for subsequently recalling and redisplaying said output.

11. A meter system according to any one of claims 7 to 10, including selection means operable to pre-select said sequence.

12. A meter system according to any one of claims 1 to 11, including adjustable modification means for modifying the output of the computing device in a pre-selectable manner.

13. A meter system according to any one of claims 1 and 3 to 12, for use in calibrating an instrument such as a taximeter of said wheeled vehicle, including a surface movable in contact with said vehicle wheel or wheels, so that said rotation of said wheel or wheels can be effected with said vehicle stationary, said transducer system being drivably connected to said movable surface.

14. A meter system according to claim 13, wherein said movable surface comprises a roller or rollers.

15. A meter system according to claim 7 or any one of claims 10 to 14 when dependent on claim 7, including automatic means for effecting advancement of said meter system for one said test operation to the next said test operation in the sequence.

16. A meter system according to claim 15, in combination with a taximeter to be calibrated, said automatic means comprising a switching device applied to or incorporated in the taximeter.

17. The combination of claim 16 wherein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (21)

**WARNING** start of CLMS field may overlap end of DESC **. fare rates. Furthers if desired, the meter system may be provided with a print-out. Still further, the meter system is not limited in use to the checking of taximeters but may be used for checking vehicle speedometers or odometers or for any other suitable purpose. Still further, it is possible to use two meter systems according to the invention respectively as a taximeter and as a meter for checking such taximeter in which case it is also possible to provide an interactive connection between the two meter systems whereby any detected error can be automatically corrected. WHAT WE CLAIM IS:

1. A meter system for use with a wheeled vehicle, for measuring and displaying information related to rotation of a road wheel or wheels of the vehicle, comprising an electrical transducer system which is adapted to be mechanically coupled to said vehicle wheel or wheels so that in use such system is operable to produce an electrical output in dependence on wheel rotation, an electronic programmed computing system including a central sequential processing unit and memory means, said computing system being connected to said transducer system so as to be operable in use to produce an electrical output obtained by processing said transducer system output with a predetermined conversion factor or factors in dependence on the programming of said computer system, and a display device connected to said computing device and operable to produce a display or read-out indicative of the said computer system output.

2. A meter system according to claim 1, which is a taximeter, said computer system being programmed for conversion of said transducer system output into an output representative of a distance- and/or timebased monetary value or fare.

3. A meter system according to claim 1, for use in calibrating an instrument such as a taximeter of said wheeled vehicle, said computing system being programmed for conversion of said transducer system output into an output representative of a linear distance.

4. A meter system according to claim 1 or 2, for use in calibrating an instrument such as a taximeter of said wheeled vehicle, wherein said computing system is also operable in use to produce a further output which is obtained by processing an output other than from said transducer system with a further respective conversion factor or factors, said display device also being operable to produce a display or read-out indicative of such further output.

5. A meter system according to claim 4, further including a timing device and wherein the or one such other output which is processed constitutes the output of said timing device, the corresponding said further output of the computing system being representative of an elapsed time.

6. A meter system according to claim 4, wherein the timing device is arranged to produce regularly spaced timing pulses and said computing system is programmed for counting same to produce said elapsed time output.

7. A meter system according to any one of claims 1 and 3 to 6, for use in calibrating an instrument such as a taximeter of said wheeled vehicle and wherein said computing system is programmed to follow a sequence of test operations at least some of which correspond to production of outputs by said computing system which are functions of different outputs which are processed and/or different conversion factors.

8. A meter system according to claim 7, wherein a switch is provided for advancing the meter system from one said test operation to the next said test operation in the sequence.

9. A meter system according to claim 8, wherein said switch is a hand switch.

10. A meter system according to any one of claims 7 to 9, wherein recording means is provided for recording the output of the computing system at the end of a test operation, and recall means is provided for subsequently recalling and redisplaying said output.

11. A meter system according to any one of claims 7 to 10, including selection means operable to pre-select said sequence.

12. A meter system according to any one of claims 1 to 11, including adjustable modification means for modifying the output of the computing device in a pre-selectable manner.

13. A meter system according to any one of claims 1 and 3 to 12, for use in calibrating an instrument such as a taximeter of said wheeled vehicle, including a surface movable in contact with said vehicle wheel or wheels, so that said rotation of said wheel or wheels can be effected with said vehicle stationary, said transducer system being drivably connected to said movable surface.

14. A meter system according to claim 13, wherein said movable surface comprises a roller or rollers.

15. A meter system according to claim 7 or any one of claims 10 to 14 when dependent on claim 7, including automatic means for effecting advancement of said meter system for one said test operation to the next said test operation in the sequence.

16. A meter system according to claim 15, in combination with a taximeter to be calibrated, said automatic means comprising a switching device applied to or incorporated in the taximeter.

17. The combination of claim 16 wherein

the switching device is incorporated in the taximeter and is connected to the meter system via a socket of the taximeter.

18. A meter system according to claim 1, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

19. The combination according to claim 16 or 17, or the combination of a meter system according to any one of claims I and 3 to 15 and 18 for use in calibrating a taximeter of said wheeled vehicle with said taximeter wherein the meter system and the taximeter are provided with an interactive connection therebetween whereby any detected etror in the taximeter can be automatically corrected.

20. The combination according to claim 19, wherein the taximeter is as claimed in claim 1 or 2.

21. A meter system according to any one of claims 1 and 3 to 15 and 18 when used to calibrate a taximeter of a wheeled vehicle.