GB2140922A - Carrying out value input and output operation to a trip recorder microprocessor using the recorder display. - Google Patents

Abstract

In an electronic trip recorder a microprocessor 1, via a stepping motor 7, controls display 14 and recording means 13 according to signals received from various transducers, in normal use. A switching means 4 produces pulse sequences which enable the display to be deflected other than in response to the transducer signals. To feed in calibration information e.g. an actual speed, switch 4 is operated until the corresponding deflection at the display has occurred. Corresponding information is stored under control of the microprocessor and used during calibration to produce a constant enabling current conversion between transducer signal and displayed quantity. Such constant may be displayed by appropriate operation of the switching means so that the display is deflected until it automatically stops at a position corresponding to the constant (repeated deflections may be involved, one for each digit of a multi-digit number, in both input and output operations). The pulse sequence from 4 may be briefly interrupted at well defined display positions (10 kph = 1, 20 kph = 2, etc). <IMAGE>

Description

SPECIFICATION Method of and arrangement for carrying out value input and value output operations by using the display and recording means of a trip recorder The invention relates to a method of and an arrangement for carrying out value input and value output operations by using the analogue display and/or recording means of a trip recorder, wherein the measured values representing the motion or engine movement are fed in by means of an electrical "wave" and are processed by means of an electrical measuring mechanism.

In the case of conventional trip recorders driven by a mechanical rotary movement, it was conventional to adapt the instrument to the vehicle or to its engine by using assimilating transmissions constructed as a particular component and consisting of interchangeable gearwheels. It is well-known that the speed of revolution of the gear mechanism or wheels in relation to a specific distance travelled will vary from one type of vehicle to another, while the instruments which record or display the rotary values of the transmission or wheels or even of the engine and which are mounted in these vehicles, such as for example the trip recorder, are calibrated to a uniform input speed at the time of manufacture so that later, when the recording instrument is installed into the vehicle, it is adapted to the vehicle concerned.

Consequently, in the case of conventional trip recorders and tachometers driven by mechanical rotary movement, the fitting of these instruments entailed a not inconsiderable complication and expense, and it should be remembered that the transmission ratios indicated by the manufacturers for the output shaft of the gear mechanism or engine, for connection of the trip recorder, are not the same even with all the vehicles of one type, due to the fact that under certain circumstances, the vehicles may be fitted with different tyres. In prac tice, therefore, it was necessary individually to adapt every measuring instrument to the vehicle after it had been installed, the manufacturer's details concerning output speed of the gearbox or engine being regarded only as an approximate value.

To this end, workshops installed a rolling test bed, with which the already installed instrument could be adjusted by means of complicated diagnostic equipmentto a specific rotary speed or travelling speed set on the rolling test bed.

Where smaller workshops are concerned, adaptation of the trip recorder or speed recorder to the vehicle was undertaken without a rolling test bed in that the vehicle was caused to travel over a measured path, the recorder being adapted to the vehicle with the help of the rotary speeds ascertained in the process.

Of late, trip recorders with an electrical measuring mechanism and an electrical drive "shaft" have been devised which have the advantage of being simpler to install because, on the one hand, the laying of an electrical cable causes fewer problems than the laying of a mechanical drive shaft and because, on the other hand, the electric trip recorder is so conceived that it can be internally adapted to the vehicle and so requires no special assimilating gear mechanism.

However, since the electrical measuring system is an analogue meter and since adaptation to the vehicle takes place by adjusting a potentiometer to a voltage value corresponding to the value to which the instrument is being adapted, it is necessary in order to fix a correct adaptation of the installed trip meter, to use a diagnostic apparatus which furnishes a digital display of the conversion factor in order to be able to establish that the instrument has been correctly adapted to the vehicle.

In the case of motor vehicle instruments which operate digitally, for example taxi meters, adaptation to the vehicle has already been undertaken in that the adaption value is fed in digitally by either externally fed-in series of pulses or by contacts located in the instrument. However, for monitoring the correct input of values, the taxi meter has the advantage that it is also provided with a digital display so that it is possible for the input adaptation value to be displayed digitally on this display medium.

No such procedure can be carried out with a trip recorder which is provided with analogue display and recording means, since there is no possibility of monitoring the adaptation value at input or at any likely further output through an electronic digital display.

The object of the invention, therefore, is to make adaptable to the vehicle a trip recorder having analogue functioning display and recording means where such a vehicle is provided with an electrical measuring mechanism and with an electrical "shaft", dispensing at the same time with the use of a special diagnostic apparatus.

The prerequisite for this is not only the possibility of feeding in the "rotary values" of the vehicle via the normal-drive, but also the possibility of storing the resultant adaptation values and, above all, displaying the adaptation values which are so stored, but also the possibility of being able to feed them in directly. Displaying the stored adaptation values serves to monitor correct adaptation by the workshop staff and possibly some calibrating official. The input of the correct adaptation values serves to accelerate the adaptation process. By feeding in the adaptation values indicated by the manufacturer, it is possible in this way to arrive at a preliminary adaptation and all that is then necessary is to make slight adjustments in order to adapt the trip recorder to the individual vehicle concerned.

The invention therefore envisages on the one hand a method of and an arrangement for carrying out value input operations with the display and/or recording means of a trip recorder, in which the measured values representing the motion or engine movement are processed digitally by a microprocessor, the output values thereof are caused to act through a digital control system of a stepping motor on analogue display and recording means, characterised in that special switching means make it possible to trigger a sequence of special pulses for the stepping motor, by which the display and/or recording means can, independently of the measured values representing vehicle motion, be moved out of the zero starting position into the fully deflected position and back and in that the deflection movement can be interrupted by the special switching means, the extent of the deflection movement being processed by the microprocessor as a value input and the display and/or recording means being returned to the zero position.

Furthermore, the invention provides a method of and an arrangement for carrying out value output operations with the display and/or recording means of the trip recorder, wherein the measured values representing the motion or engine movement are processed digitally by a microprocessor, the output values of which are caused to act through a digital control system of a stepping motor on analogue display and recording means, characterised in that special switching means can trigger a sequence of special pulses forthe stepping motor, by which the display and/or recording means, independently of the measured values representing the motion of the vehicle, can be moved out of the zero starting position and into the fully deflected position and back, and in that the deflecting movement is interrupted by internal control commands from a programme memory controlling the microprocessor and as a function of stored values for the purpose of value output and the display and recording means are returned to the zero position.

Input and output operations are so controlled thereby that for input or output of the digit "5", the display means of the trip recorder is moved into the position 50 kp/h or is arrested in that position, while for the input or output of the digit "7", the display means of the trip recorder is moved into the position 70 kp/h and for example for input or output of the digit "0", it is moved into the position 100 kp/h.

In order not to let the series of special pulses which, via the stepping motor, move the display means into the value input or output position, work at too slow a pulse sequence frequency, the control system is so envisaged that at each input or output position of the display means of, for example 30 kp/h, 40 kp/h, etc., there is a brief stopping of the display means to facilitate reading the output value or the input of the value with the special switching means.

If it is desired to exclude all possibility of movement of the recording means during the operations of input and output monitoring of the adaptation values, then it is possible to provide in the parts of the transmission between the display means and the recording means an electromagnetically engageable and disengageable coupling so that there is no recording of the input and displayed values.

At the start of every adaptation process, the display means of the trip recorder must first be moved once stepwise through all the display positions by the sequence of special pulses so that the operator has an opportunity of indicating to the instrument which operation he wishes to carry out, in other words for example the display of the already set adaptation value for speed or the input of the adaptation value for engine speed, etc.

The invention will now be described in greater detail hereinafter with reference to the accompanying drawings, in which: Figure 1 shows the hardware components of the arrangement by means of which the method according to the invention, while Figures 2 and 2b represent the procedural steps involved.

As Figure 1 shows, the electrical measuring mechanism of the trip recorder is provided with a microprocessor 1 which receives its internal cadence from a clock generator 2. The system also contain a system memory 3 in the form of an ROM orEPROIVI together with input ports 4 and output ports 5. Any desired number of keys T1 toT4 can be connected to the input ports 4, only some of them serving to control the arrangement according to the invention, while other keys are used for other purposes, for example for controlling the working time recorder, etc.

Also connected to the input ports 4 are transmitters Ga, G2 and G3, for example for transmitting the distance travelled, and transmitters for the engine speed, but for example also a transmitter for fuel consumption and the like, if the trip recorder is connected to a fuel consumption meter.

The output ports 5 are connected via drivers 6to a stepping motor 7, the purpose of which is, via its output shaft and a gear mechanism 9 on the one hand to drive display means 10 which takes the form of a pointer, while on the other hand it also drives, through a gearwheel 11 and a rack 12,a recording means which takes the form of a recording stylus 13, which records the measured values on a chart which is not shown here for the sake of clarity. The pointer 10 is the standard speed pointer which on a scale 14 and under normal operation indicates the speed of between, for instance, 0 and 120 Kp/h. There is always a mechanical connection between the gear mechanism 9 and the pointer 10 and the gearwheel 11, indicated by two shafts 15 and 16, although of course this connection may be achieved in any other form using mechanical components.A constituent part of the gear mechanism 9 is also a coupling which can be engaged and disengaged by an electromagnet 17, ensuring that the connection 16 between the gear mechanism 9 and the gearwheel 11 is interrupted so that the stepping motor 7, via the connection 8, the gear mechanism 9 and the connection 10, only drives the pointer 10, so that the stylus 13 remains stationary. The component parts of the electrical measuring mechanism of the trip recorder, comprising the processor i, the system memory 3, the input and output ports 4 and 5 are interconnected via address bus lines B, and data bus lines B2.

In normal use, the transmitters G1 to G2 generate pulses which correspond either to the distance travelled or to the engine speed, etc. These values are received by the processor 1 and are offset against a preset constant, the adaptation value for the vehicle. The result is the relevant desired speed which should be stored in the processor as a desired value. At the same time, during measured value processing in the processor, the displayed or recorded actual speed at any given time, i.e. the position of the pointer 10 and of the stylus 13, is stored as an actual speed. The processor now carries out a comparison between the desired value and the actual value. This comparison then produced a control value for the stepping motor, this value being fed to the stepping motor 7 via the output ports 5 and the drivers 6.The stepping motor adjusts the pointer 10 and the stylus 13 by as many steps as are needed for the actual value and the desired value of the speed to coincide with one another.

For the purposes of the present invention, Figure 1 shows the three keys T1 to T3 which pass through the front panel and which are electrically connected to the input ports 4. In addition to other keys which may possibly be provided for other purposes, the keys T1 to T3 are a constituent part of the arrangement according to the invention and of the method according to the invention for the input and output of values into and from the trip recorder.

The system memory 3 contains not only the control commands for the processing of the ingoing measured values from the transmitters G1, G2, G3 but also a special programme part for carrying out the method according to the invention, for value input and output. The keys T1 to T3 are the so-called special switching means, the key T1 serving to switch over from normal measured value processing to the adaptation process in order to activate the corresponding programme parts in the system memory 3. The key T1 must be switched on and off, i.e. it remains depressed as long as an adaptation process is taking place and must be disengaged again manually afterwards. The key T1 is the key by means of which the value input process is brought about while the key T3 is the key which triggers the measuring process during measured value detection for adaptation purposes.

The way in which the method takes place in detail will be described particularly with reference to Figures 2a and 2b. An important pre-requisite however is that, for the purposes of the method according to the invention, where a trigger command is present, key T1, by means of the microprocessor 1 and the clock generator 2, generates special pulse sequences which are fed to the stepping motor 7 via the output ports 5 and the drivers 6, the pulses being utilised in orderto move the pointer 10 in each case from the zero position into the position of full deflection. As this happens, the stepping motor moves the pointer in ten steps from 0 to 10 kp/h, in a further 10 steps from 10 to 20 kp/h.

In order to facilitate value input and output, the special pulse sequences are however interrupted for a short time after every ten steps of the motor 7 so that the pointer sticks for a short time in each case at 40 kp/h, 80 kp/h, etc.

The method of the invention will now be described particularly with reference to Figures 2a and 2b, a distinction having to be made between three broad categories of detection/output operations: a) the category of automatic detection of the conversion factor for speed, distance and engine speed; b) the category of output operations for the already stored adaptation value for distance and engine speed, and c) the category of input operations for these values.

Associated with each of these operations is a code number for implementing the method according to the invention, for example in the following sequence: 1. Automatic detection of the adaptation factor for travelling speed and distance by means of a rolling test bed.

2. Automatic detection of the adaptation factor for v and s by travelling along a test distance.

3. Automatic engine speed detection by using a stroboscope.

4. Input of travelling speed adaptation factor.

5. Display of travelling speed adaptation factor.

6. Input of engine speed adaptation factor.

7. Display of engine speed adaptation factor.

8 and 9. Reserve code numbers for further function tests.

The above explanations of the code numbers 1 to 9 will provide the above three categories a to c. The code numbers 1 to 3 denote the detection of adaptation values according to a, while code numbers 4 and 6 comprise digital input of the already known adaptation values according to c and code numbers 5 and 7 the output of the adaptation values according to b, set in the instrument. In Figure 2, the system programme 100, as stored in the system memory 3, is the starting point of the method.

Normally, measured value processing is carried out according to 101. When necessary, then, a command can be given via the key T1 (Code "On" 102) that now it is necessary for detection, display or output of adaptation values. As no adaptation value will as yet have been ascertained in the case of a newlyinstalled instrument, it is necessary according to 103 Mode-Code No. ? to ascertain whether a detection operation a (Code No. 1 to 3, see above), an output operation b (Code No. 5 and 7) or an input (Code No.

4 and 6) is to take place. In the case of the newly-installed instrument, there is no code number available, so that Code 0 is recognised, which is equivalent in meaning to an input operation. Now the method takes place as shown in Figure 2b.

According to 105, via the Code No. (in this case 0), a memory in the processor 1 is prepared and is intended to accommodate the code number. The processor now generates the sequence of special pulses according to 106. This special pulse sequence so drives the stepping motor 7 that it runs from 0 to 10, to 20, to 30, etc., kp/h.

Let it be assumed now that the travelling speed and distance values are to be detected by the rolling test bed. Consequently, the operator, when the pointer 10 reaches the display position corresponding to 10 kp/h, presses the button T2 so storing the value "1" in the memory selected according to 105.

The stepping motor 7 is reversed and run back (109) until it has reached the zero position. The special pulse sequence is then triggered once again, the pointer in each case passing through the individual positions of the display until, in a final programme step, it is established that no further digits need to be input (110). A signal is passed back to the system programme to the effect that the first process of code input is concluded.

The vehicle now stands firstly on the rolling test bed. The key T, is pressed and as a code number the digit "1" is stored in the memory to denote automatic recognition ofthe adaptation value by the rolling test bed. The drive roller of the rolling test bed is accelerated to a specific speed of, for example, 60 kp/h which is indicated at the rolling test bed and this speed is then maintained. This is indicated on a speedometer connected to the rolling test bed. Since the key T1 (Code "On") remains depressed, there is no normal processing of the ingoing measured values according to 101 and thus no normal control of the display and recording means of the trip recorder, but it is first of all established from the code number according to 103 which of the operations a to c is to occur.According to 120 (Code No. = Detection Mode), it is established that Code No. "1" (automatic detection of the adaptation values for v and s by means of the rolling test bed) is stored according to 105. When the roller of the rolling test bed has reached a constant speed of 60 kp/h, then the operator presses the button T3, which is recognised according to 121, so that now the detection programme v and s rolling test bed 122 can take place, a programme which is only to be described in broad outlines. This particularly on account of the fact that during detection of the adaptation values, the display and recording means of the trip recorder remain stationary. The processor 1 of the trip recorder counts, controlled by the system memory 3, how many pulses enter the unit in a specific period of time at a travelling speed of 60 kp/h.This value is related to a constant, the constantofthe apparatus, and the processor ascertains therefrom an adaptation value which is then stored in the memory. A similar process takes place for adaptation to distance. In the rolling test bed, after actuation of the key T3 according to 121, the drive roller is driven for a very specific distance and is then stopped. Here, too, the processor counts the pulses generated by the transmitter G1 during this travel, compares the total with a constant and then calculates and stores in its memory the adaptation factor. Separate detection of the distance and travelling speed values is necessary particularly where measured value processing displays and records the distance and travelling speed values by separate display and recording means.After these processes are concluded, key T1 is disengaged because prior to detecting for instance the engine speed values, it is necessary first to feed in a new code number which is done directly by pressing in the key T1.

A similar procedure is adopted if, for detecting the adaptation value S, it is necessary to travel over a test distance according to 123. Instead of the Code No. 1 according to Figure 2b 107, it is necessary for this purpose to input the Code No. 2 according to 111 and store it according to 112. Then the vehicle is caused to travel over the test distance and at the moment when the starter marking is reached, a switch-on signal is given via the key T3 and the process takes place according to 123 in that once again the incoming pulses are counted. Renewed actuation of the key T3 as the vehicle travels over the end marker of the test distance terminates the detection process, the number of pulses received is compared with a constant and the processor 1 of the trip recorder calculates from this adaptation value which is then stored in the memory of the processor.

Instead of actuating the key T3 to detect the adaptation value by using the test distance, it is also possible to provide a photoelectric cell arrangement at the start and finish of the test run.

Part 124 of the procedural apparatus is used for detecting the adaptation values for engine speed n.

In order to trigger this part of the process, it is necessary first of all again to desengagethe key T1, depress it again and then feed in the Code No 3 according to Figure 2b through the key T2 in position 30 kp/h. A marker is provided on a part of the vehicle which rotates in accordance with the engine speed.

A stroboscope establishes when the specific preset number of engine revolutions is reached. For constant engine speed, then, the key T2 is depressed in the detection process so that the pulses received from the engine speed transmitter G2 are counted.

After a certain detection period, the process is concluded, the number of pulses received until that moment, representing revolutions ofthe engine, is compared with a constant and a conversion factor is computed which is stored in the memory of the processor 1 as an adaptation value. It goes without saying that the part 124 of the method need only be carried out if the trip recorder is an instrument which also has facility for recording and displaying engine speed.

For displaying the adaptation values stored in the memory, it is necessary after actuation of the button To, to feed in the Code No. and 6 - according to whether it is intended to display the travelling speed adaptation factor of the engine speed factor. The way in which this happens has already been described hereinabove. After actuation of the key T1, the stepping moves the pointer stepwise from the positions 10 kp/h, 20 kp/h,etc., into the positions 50 kp/h, 70 kp/h. According to Figure 2b, whenever the correct and desired position is reached, the key T2 is depressed, so that further movement of the pointer is prevented and the corresponding digit is stored as a code number.T1 (Code "on") remains depressed and it is now recognised according to 103 that either the code No. 5 or 7 is set so that a part of the process is triggered according to b in that once again a special pulse sequence is fed to the stepping motor according to 130. In every stopped position of the pointer there is a comparison between the actual position of the pointer and the value stored in the first position of the memory (131) which has adopted the adaptation value for travelling speed or engine speed. If there is any discordance, the stepping motor continues to run while in case of uniformity, according to 132 (stop stepping motor), the stepping motor is stopped for a somewhat longer period so that the operator can read off and note the appropriate figure. The stepping motor is then reversed and runs back into the starting position (133 return stepping motor) Until the last position (134) of the adaptation factor is reached, a fresh special pulse sequence (130) is triggered again in the zero position (135) so that the stepping motor again deflects the pointer from the zero position and brings it into the individual display positions until, in comparison with the values stored in the memory for the adaptation factor, the second position is correctly indicated, so that the stepping motor stops (according to 132), runs back (according to 133), until all figures of the displayed value have been displayed one after another.If all the figures are called forward one after another, then according to 134a signal is passed back according to 100 to the system programme to the effect that the display process is concluded. The key T1 must then be disengaged again.

A value input process takes place in a manner similar to that already described for the code number and as shown in Figure 2b. Firstly, the code number for an input process - in other words 4 or 6 has to be fed into the unit. It is then decided according to 103 that an input process c is involved.

According to 105 (Code No. Select Memory), then, the corresponding memory is prepared for selection.

The special pulse sequence causes the pointer to run through the various display positions and the key T2 is depressed at whichever place is required. The value indicated by the pointer in this position is stored in the memory prepared according to 105 (108,112). The pointer runs back into the zero position and until such time as the final digit (110) is fed in, the pointer setting process is repeated, all the digits representing the adaption value being fed in one after another. Once the final digit according to 110 has been fed in, there is another signal fed back to the system programme according to 100. Before the trip recorder can resume its normal measured value processing again, it is of course necessary for the key T1 to be disengaged. Only then is it possible according to 101 to resume normal measured value processing.

The method described and the arrangement described make it possible for adaptation of the trip recorder to the transmitters to bring about input and output of adaptation factors with a negligible extra cost in terms of hardware for the apparatus - a few keys, a little programme storage capacity - while using normal display and recording means.

Claims (8)

1. Method of and arrangementforcarrying out value input operations with the display and/or recording means of a trip recorder, wherein the measured values representing the motion or engine movement are processed digitally by a microprocessor, the output values of which are caused to act through a digital control system of a stepping motor on analogue display and recording means, characte rised in that via special switching means (T1 to T3) it is possible to trigger a series of special pulses for the stepping motor (7), by which the display(10) and/or recording (13) means can be, independently of the measured values representing travel motion, moved out of the zero starting position into the full deflection position and back, and in that the deflecting motion can be interrupted by the special switching means (T2), the extent of deflecting movement being processed by the microprocessor (1) as a value input, while the display and recording means (10,13) are returned to the zero position.

2. Method of and arrangement for carrying out value output operations with the display and/or recording means of a trip recorder, wherein the measured values representing the motion or engine movement are processed digitally by a microprocessor, the output values of which are caused to act through a digital control system of a stepping motor on analogue display and recording means, characterised in that it is possible through special switching means (T1 to T3) to trigger a special pulse sequence for the stepping motor (7), by which independently of the measured values representing the travel motion, the display (10) and/or recording (13) means can be moved out of the zero starting position into the position of full deflection and back, and in that the deflecting movement is interrupted by internal control demands of a programme memory (3) controlling the microprocessor (1) and as a function of stored values, for the purpose of value output, the display (10) and recording (13) means being returned to the zero position.

3. Method and arrangement according to Claim 1 or 2, characterised in that the special switching means (T1 to T3) take the form of manually operable keys.

4. Method and arrangement according to Claim 1 and 3, characterised in that one key (T1) serves to start the full deflection movement of the display and/or recording means while actuation of the other (T2) interrupts the deflecting movement.

5. Method and arrangement according to Claim 1 or 2, characterised in that one key (T1) has a test release function, while a second key (T2) has a value input function.

6. Method and arrangement according to Claim 1 or 2, characterised in that the special pulse sequence is so fed to the stepping motor of the microprocessor that there is a brief stoppage at each intermediate position of the display means (10) corresponding to the full "tens" (20,30,40... kp/h) position.

7. Method and arrangement according to Claim 1 or 2, characterised in that there is disposed between the display (10) and recording (13) means a coupling which can be released for the purposes of value input and output operations, so that only the display means (10) need be driven in the form of value input and output pointers which move over scales.

8. Method of and arrangement for carrying out value input operations with the display and/or recording means of a trip recorder substantially as herein described with reference to the accompanying drawings.