DE3111130A1 - Operating procedure for a vehicle navigation device and arrangements for carrying out the procedure - Google Patents

Abstract

This navigation arrangement contains a displacement sensor for generating signals indicating the vehicle movement, and a course gyro for continuously detecting the alignment of the vehicle compared with a reference direction. To eliminate a course error produced by the drift when the vehicle is stopped, the angular change of the gyro in the angle determination between the alignment of the vehicle and the alignment of the course gyro are not taken into consideration when the displacement signals are missing; however, the system additionally monitors whether this angle changes more quickly than is possible due to the maximum drift plus a safety margin. If this is so, or if displacement sensor signals occur again, vehicle travel is assumed and the angular changes are no longer suppressed. <IMAGE>

Description

Operating procedure for a vehicle navigation

device and arrangements for carrying out the method The invention relates to an operating method for a vehicle navigation system that has a Position transducer, which generates signals corresponding to the vehicle movement, a gyroscope arrangement, which continuously detects the orientation of the vehicle in relation to a reference direction and an evaluation circuit that contains the position sensor and the gyro arrangement The received signals are processed and in the absence of those indicating the vehicle movements Signals from the encoder makes a device effective that the when the Drift of the gyro arrangement occurring in the vehicle is at least largely disregarded - leaves.

Furthermore, arrangements for carrying out this method are the subject matter the invention.

Vehicle navigation systems of the type discussed here have, for example as a gyro arrangement, at least one course gyro or an operating mode "course keeping" on, by means of which the current alignment of the fan tool axis with respect to a Reference direction, e.g. north, is determined. For this purpose, the heading axis shows either even to the north or in any arbitrary, but at a known angle & k Direction deviating from north. In the former case is the measured orientation the vehicle axis compared to the reference value (north) directly the course of the vehicle, while in the case of any orientation of the course gyro itself the course «from the measured value iF of the vehicle axle against the alignment of the course gyro and the angle ROCK according to the relationship: to K O K + from the course angle d and the signals of the encoder can be in the evaluation circuit .current Calculate the location of the vehicle.

As is well known, however, every course top also has a drift component which is known neither by size nor by direction, but one of the quality of the gyro has dependent maximum value. About the resulting falsification Various methods are known to keep the market value small; so the additional Use of a north-pointing roundabout; with which the course gyro alignment of From time to time is redefined, or the approaching of well-known places and one Calculation of the deviation from the determined location error.

Vehicles carrying navigation systems, e.g. military vehicles, tanks, in particular, are used for a large part of the deployment time quiet. The course top also drifts during this downtime. It is known (DE-OS 19 15 477), to suppress the drift while standing by, when absent of signals indicating vehicle movement, the gyro locked, i.e., its Twist axis during the stop in accordance with that at the beginning of the vehicle stop held position.

With this drift suppression when the vehicle is stopped, it can happen when starting again there are considerable angular errors, since the vehicle movements up to the arrival of the vehicle indicating signals that cancel the lock again, already significant changes the alignment of the vehicle axis and because of the lock with it the course top alignment can also come about. This error can occur when starting a wheeled vehicle with a large steering wheel angle, especially in the case of tracked vehicles, di rotary movements can occur on the spot.

The invention is based on the object while maintaining the gyro drift suppression to avoid the occurrence of this angle error when the vehicle is stopped.

This object is achieved by the features specified in claim 1.

The invention also relates to various arrangements for implementation this operating procedure.

If, for example, in a navigation system, the angle XF between the vehicle orientation and the heading of the gyro as a signal corresponding to this angle output from the pick-up of the gyro, according to one embodiment, comparison means provided in which the consecutively determined angles aF (or the dependent angles are compared with each other. As long as the change in the angle a predetermined value A, which is the sum of the maximum possible drift of this gyro plus corresponds to, does not exceed, a safety surcharge, it is assumed that that the vehicle is still standing. Locking means then prevent these changes in angle due to the drift are included in the course calculation and thus cause an error. However, if it is determined that the amount A is exceeded, the blocking means Unlocked immediately, as there must now be a movement of the vehicle. However, since the Alignment of the course gyro during the holding time in relation to the gyro housing and thus has also rotated by iid with respect to the alignment against the reference direction, must the angle N has to be corrected with the correct sign.

There are also gyros where the tap is fixed to the vehicle The gyro housing and the outer gyro frame after twisting each one a lot a small angle of e.g. six angular minutes emits a change impulse.

The direction of rotation results from different impulses Polarity. Here, too, further consideration is given if there are no path impulses these pulses are initially interrupted in the evaluation circuit. According to one embodiment the invention is checked at predetermined small time intervals of e.g. 10 seconds, whether the sum of the change impulses, which were added with the correct sign, is an upper one or lower threshold, which is the maximum drift of the gyro plus a safety margin corresponds to, exceeds or falls below. If this is the case, the journey is assumed and the added change pulses are used to correct the angle NF. If, on the other hand, none of the thresholds is exceeded, the angle is not corrected NFw because then only a drifting of the gyro is assumed. The one at vehicle stop In contrast to the above exemplary embodiment, the accumulated drift value is required here cannot be taken into account for the angles fF and N.

The method according to the invention can also be used with an arrangement perform, in which, if there are no displacement pulses, a on the precession axis attached torque generator is applied with such a current that a precession movement about the azimuth axis comes about that is slightly larger than is the emigration speed at maximum drift. In addition, there are switching means provided, which is then given a predetermined slight change in the gyro alignment - in both directions of rotation - generate a signal that reverses the polarity of the current of the torque transducer is used and thus a precession movement in the opposite direction causes. The gyro alignment thus fluctuates in a small area around the Start of vehicle stop existing alignment. The drift can affect the gyro alignment not Bring out of this area, as the drift movement is definitely greater Precession movement is superimposed. If, on the other hand, there is a change in the direction of the gyro at a rate of rotation that is greater than the precession motion due to it is the moment generator, so can. the precession movement exceeding the Area do not prevent; the changes in the orientation of the gyro go there a blocking did not take place here immediately in the determination of the angle cL F. It is true that the change is somewhat falsified by the opposing precession movement; However, since the precession speed is low, the direction of rotation continues changed. and a displacement pulse is expected within a short time (a few seconds) that switches off the torque sensor is the error caused by this negligible. As there is no misalignment of the gyro due to the drift when stopped runs up, the angles tF and s need not be corrected here either.

The pick-up of the gyro gives impulses for change when the From the azimuth axis, these change pulses cause the current to reverse the polarity.

A particular advantage of this drift detection procedure is that that one does not - as usual - watch the top for a certain time, but rather practically the entire previously unknown idle time of a vehicle as a time base can use, resulting in high accuracy.

Exemplary embodiments of the invention are explained in more detail with the aid of the drawing explained.

There are shown Fig. 1 - an embodiment in which the tap of the The course gyro emits a signal corresponding to angle 4, Fig. 2 and 3 - exemplary embodiments in which the tap supplies change pulses increments, Fig. 4 - an embodiment in which during the vehicle stop the outer frame of the top in a pendulum motion about its alignment at the beginning of the vehicle stop is held.

In Fig. 1 with 1 is a course gyro, with 2 a displacement encoder, which after emits a pulse in certain distance sections of e.g. 1 m and an evaluation circuit with 3 designated.

In the first of the arrangements described above, the during of the vehicle stop due to the drift accumulating gyro rotation determined to with it to determine the new angle. This top rotation is a measure of the Drift of the top. According to a further development of the invention, this is taken into account the holding time is determined in angular degrees per unit of time. You may in the aftermath to correct the falsification of the course - directly or after an assessment can be used with a factor of C 19 due to the gyro drift. Even with the other solutions given is by adding up the increments when the vehicle is stopped a drift determination is possible.

The drift is also determined in the example explained above possible with pendulum swing of the gyro, in that one in each case the duty cycle of a pendulum process determines the corresponding times added up to values T1 and T2.

From the equation T2 - T1 = O ° C p T2 + T1 (oU O and ocp are the Rotational speeds due to drift and Commute, and T2 is the bigger one Time) the drift can be calculated, which is then taken into account as above can.

When driving, the course gyro delivers an angle α F between The vehicle axis and the random heading gyro alignment signal, e.g. as a digital value to the evaluation circuit 3. This is also the angle & K supplied from a block 4; this angle corresponds to the angle between the random orientation of the course top and the north direction. In which form this angle αK is determined from time to time, can be left open here stay. When driving, the course whether the vehicle is in the evaluation device from the relationship Ct = N + «. as well as the location coordinates by evaluating the path impulses with the Sine or cosine of the respective course angle 01 and addition of these evaluated Sizes gained.

A timer 5 is connected to the output of the encoder 2, which if there are no output pulses from encoder 2 after a specified time of e.g. 10 seconds (definition: vehicle is stationary) a control signal is generated. This control signal causes via an AND gate 6 that a gate 7 blocks the line (connection) 8. During the subsequent holding time, changes in the course gyro alignment occur, which can arise due to random gyro drift, not for the evaluation circuit; much more the angle N present before the “vehicle stop” criterion is retained there.

Furthermore, the output signal of the timing element 5 sets a comparator 9 in operation; this saves the first one after the appearance of the output signal of the timing element 5 occurring angle value w 1 and compares this with that of the angle value CtF2 determined in the next measurement. The difference value i \ R 1 becomes a threshold stage 10 and a summing element 11 are supplied. The threshold of the Level 10 is chosen so that the threshold value is due to the gyro drift A cannot be exceeded (corresponding to the maximum drift plus safety margin). Thus, no output signal appears during the actual vehicle stop Threshold level 10. After the comparison, the last measured value P2 is saved and for the next measurement the new measured value AF3 will be saved with the Value compared etc. The sum of the differences of all measurements is in the summing element 11 formed with the correct sign.

If there is again a pulse at the output of position encoder 2 or is the threshold value of threshold value level 10 exceeded, - according to the definition "vehicle runs "means -then the AND gate 6 is blocked and thus the line 8 again permeable. The changes of the angle Ck F caused by the journey arrive back to the evaluation circuit.

After the vehicle has been parked for a long time, the angle between the alignment is of the course gyro and north due to the gyro drift no longer the same as the last one Angle αK, but equal to h + # # α, i.e. the one present in block 4 Angle <must be corrected accordingly. It therefore becomes a gate 12 and with it the line 15 by means of the disappearing output signal of the AND gate 6 below With the help of an inverter 13 made permeable and thus the value tts to the correct sign Correction of the value t is supplied to block 4.

In the exemplary embodiment of FIG. 2, the displacement encoder corresponds to 2 'and the timing element 5 'the corresponding elements 2 and 5 of Fig. 1. The tap of the Heading gyro 1 'gives here (instead of an angle value) when the outer gyro frame to the housing of e.g. every 6 minutes a change impulse, where its polarity depends on the direction depends. The evaluation circuit 3 'determines the angle from the change pulses coming via line 8' s, which is indicated by the sub-block 3a '.

An AND gate 20 is switched into line 8 ', which is activated when the vehicle is stopped is blocked by the output signal of the timing element 5 'for the change pulses.

At the same time, the output signal of the timer 5 'opens the AND gate 21, so that the change pulses of the course gyro to up-down counters 22 and 23 get to know.

The up / down counters 22 and 23 have a preset and count for change pulses of one polarity in one direction and for pulses the other polarity in the other direction.

In addition, the output signal of the timing element 5 'sets a pulse generator 24 is in operation, which now sends a pulse at predetermined time intervals of e.g. 5 seconds generated. This pulse sets the threshold level 25, which is an upper and has lower threshold, in operation. The thresholds S1 and S2 arise once from the presetting Sv of the counter 22 and from the threshold deviation + d S thereof, this value by the selected pulse spacing of the pulse generator 24 as well as the maximum drift and the safety margin is determined.

When the vehicle is stopped, there is no output signal of the threshold level 25. The timing element 26 delaying the pulse from the pulse generator 24 becomes short after the occurrence of the pulse, the counter 22 is reset.

The output signal of the timer 5 'disappears first because of the When a path pulse occurs, the AND gate 20 is switched through again. The disappearing signal of the timer 5 'turns on via an inverter 13' and OR- Gate 12a a gate 12 'and the line 28 permeable, so that now the accumulated during the stop by the drift and in the up / down counter 23 standing change in the orientation of the gyroscopic axis of rotation with respect to north for the measurement the gyro drift in a measuring device 29 can be used. This so determined gyro drift can subsequently be taken into account when determining the course 01.

If the vehicle turns vigorously at the start of the journey, a Distance pulse the upper or lower threshold value of level 25 is exceeded, since a corresponding number of change pulses entered the counter 22 in the pulse pause are. The output signal of this threshold level 25 then makes a gate 27 permeable. Thus, the content of the counter 22, which is at least one by the vehicle rotation that has come about contains, to block 3a 'for the immediate correction of the there stored angle Except for switching the gate 27, the output signal is used the threshold stage 25 for the somewhat delayed resetting of the counter 23 and to reset the timer 5 ', so that this only occurs when again e.g. 10 sec. have passed without a travel pulse appearing again emits a signal. In order to the line 8 'is permeable for further change pulses.

A signal at the output of the threshold stage 25 also closes the gate 12 ', so that a drift determination is initiated by this signal and the Drift can be taken into account when determining oC.

In the embodiment of Fig. 3, the displacement encoder is again with 2 ', the course gyro, which should also issue change impulses here, with 1 ', the evaluation circuit with 3 'and a sub-block thereof in which the angle F is formed from the change pulses is denoted by 3a 'and the block over which the angle OCK is supplied is denoted by 4'. The timing element that, if no path impulses are received, after a specified time span supplies a signal is again denoted by 5 '.

As long as the timer 5 'has not responded, it is a bistable Member 30 in a position in which the AND gate 31 is permeable to the change pulses is held.

When the vehicle is stopped, i.e. after a specified time after the last The path pulse becomes the bistable element 30 through the output signal of the timing element 5 ' tilted and thus the supply of the change pulses to sub-block 3a 'is blocked.

By the element formed from the timer 32a and the AND gate 32b 32, the size of the intervals between the change pulses is monitored, the timer 32a prolongs the change impulse and is dimensioned so that it is even at maximum Drift has expired when the next change pulse occurs, i.e. no signal gives more. If, on the other hand, the next change impulse appears so early (earlier than through the maximum drift plub safety margin is taken into account in the timer) that the Time constant of the timer 32a has not yet expired, then the AND gate is 32b from a signal that tilts back the bistable element 30 and thus the supply of the Change impulses to sub-block 3a 'again allows. A disappearance of the output signal of the timer 5 'when a new path pulse occurs, is set via the inverter 33 the bistable member also back.

An up / down counter 34 is provided here for drift measurement, that, as long as the bistable element 30 is toggled by the signal of the timing element 5 ', through the AND gate 35, the change pulses are supplied. The accrued The sum of the change pulses is when the bistable member 30 is tilted back by opening of a gate 36 with the help of the RücXkippimpulses on the drift measuring device 37 for later Transfer correction of the gyro's drift behavior.

The embodiment of FIG. 4 takes a slightly different approach Achieving the same result. The course top is again with 1 ', the encoder with 2', the evaluation circuit with 3 ', the sub-block for the formation of the angle N F from the change pulses with 3a ', the element for entering the angle CL K with 4 'and the timing element for generating a signal in the absence of travel impulses denoted by 5 'for a predetermined time. By the output of the timer 5 'the gate 40 is made permeable. This makes the DC power source 41 placed via the member 42 to a torque generator 43. This is on the precession axis of the course top 1 'attached so that a moment exerted by it precession of the top around its vertical axis, which is indicated by 44 in the diagram of block 1 'of the drawing is designated, causes. Link 42 is a pole changer, i.e. a link that is in a Control signal reverses the voltage applied to the torque sensor 42 and thus a Precession caused in the opposite direction. The control input of this pole changer will be the change impulses of the course gyro supplied.

This results in the following mode of action: At the beginning of the vehicle stop the vehicle's longitudinal axis should lie in the direction of arrow 45, the twist axis of the The gyro should point in the direction of the arrow 46 and North should point in the direction of the arrow 47 lying. The absence of the travel impulses generates an output signal after a certain time of the timer 5 ', whereby the torque generator is connected to the power source. The current which is fed to the torque transmitter 43 is dimensioned so that it has a precession-des The gyro about the vertical axis 44 triggers at a rotational speed that is the maximum Drift plus corresponds to a safety margin. When the vehicle is stationary, through this precession movement in one direction is superimposed by the drift a (small) Rotation of the gyro up to the point where the pick-up of the course gyro gives a Change impuis gives causes. This change pulse switches the pole inverter 42 um, so that one of the momentary drifts was superimposed Precession movement takes place in the opposite direction until the pole changer 42 at the next change pulse is switched again. This results in a pendulum movement of the twist axis 46 of the top with a small stop, which is indicated by the double arrow 48. The twist axis is here as long as the vehicle is stationary, and no matter how big the drift is kept in a range that is determined by the resolution of the gyro tap is determined.

At the start of the journey, indicated by the occurrence of travel impulses, the precession movement is immediately suppressed. However, if the journey begins with a turn, so this speed of rotation will be greater than the speed of precession. The switching of the pole changer 42 can now also cause the gyro 1 'to migrate. not prevent. The change impulses that occur, however, immediately reach the block part 3a ', are therefore taken into account immediately. The next travel impulse switches the oscillation away.

Assuming that the journey begins with a right turn, if the pendulum motion just turns to the left, then the existing one becomes Position with the differential speed until the next change pulse occurs turned. Then the rotational speeds add up to the next change pulse etc. As a result, the already minor possible errors are largely averaged out.

Here is an example. It is assumed that the maximum drift is 1 ° / h and the precession rate was chosen to be 1.50 / h. Then it would be the mistake F, if one assumes that the next travel impulse comes after 10 seconds and in the the entire time the direction of the precession was not changed: F = 50 3,606 '10 sec.

Because of the constantly reversing polarity, the error is However still far less; it goes to zero.

Incidentally, the angle for the pendulum area can be, for example, a few angular minutes be.

Finally, it should be noted that in the examples mentioned only the non-compensable drift was taken into account. The one from the geographical Breit.e dependent, constant drift component, the so-called "apparent drift", was as compensated in another known way. Blank page

Claims (1)

P a t e n t a n s P r ü c h e 1. Operating procedure for a vehicle navigation arrangement, the one encoder that generates signals corresponding to the vehicle movement, a Gyro arrangement that continuously adjusts the orientation of the vehicle with respect to a Detected reference direction and contains an evaluation circuit, which from the encoder and the gyro arrangement received signals processed and in the absence of the Vehicle movement indicating signals from the encoder makes a device effective, at least the drift of the gyro arrangement that occurs when the vehicle is at a standstill largely disregarded, characterized in that, in addition, the change the size of the angle oCF between the gyro orientation and the vehicle orientation is monitored and that the angle changes in the absence of vehicle movement indicating signals only as a change in the orientation of the vehicle of the reference direction for the purpose of calculating the course, if they have a value that is slightly larger than the maximum possible drift. 9. Arrangement for performing the method according to claim 1 when used of a course top whose tapping the respective angle X F as this angle outputs a corresponding signal, characterized in that the feed (8) the output values of the gyro tap to the evaluation circuit (3) blocking means (7) are switched on, the output signals indicating movement while there is no movement of the transducer (2) block the feed (8) and that a comparator (9, 10) is provided which is the values obtained at the gyro tap for the angle OC F in each case in predetermined Compares time intervals and emits a signal if the deviation is a result of the maximum drift of the course top (1) plus a security surcharge The resulting value A exceeds that of this signal when the feed is blocked (8) is used to unlock them and that switching means (12, 13) are provided which the angle changes measured during the blocking and added up with the correct sign (in 11) to correct the angle X K between the heading gyro alignment and the Forward reference direction (north). 3. Arrangement for performing the method according to claim 1 when used of a course gyro, the tapping of which becomes more predetermined with every change in the angle CtF Size emits a change impulse (increment), the direction of change in each case is indicated by different polarities, characterized in that in the supply (8 ') of these pulses to the evaluation circuit (3') for the purpose of determining the The instantaneous angle W locking means (20) are switched on, which in the event of failure of the vehicle movement indicating output output signals of the displacement sensor (2 ') blocked be that a summing element (22) is provided during the blocking of this Feed (8 ') the change pulses occurring during predetermined time intervals adds up with the correct sign and emits a signal if one of the selected Time interval, the maximum drift of the course gyro (1 ') and a safety margin dependent sum of change pulses is exceeded, and that this signal for Unlocking the locking means (20) and for transmitting one of the contents of the summing element (22) corresponding value is used to correct the angle d F. 4. 'Arrangement for performing the method according to claim 1 at Use of a course gyro, the tapping of which every time the angle changes «F given size a change impulse (increment), whereby the change direction is indicated by different polarities, characterized in that that in the feed (8 ') of these pulses to the evaluation circuit (3') for the purpose of determination of the instantaneous angle tC F locking means (31) are switched on, which in the absence of any are blocked by the signals of the position sensor (2 ') indicating the vehicle movement, that a member (32) is provided which the time intervals between the change pulses of the course gyro (1 ') and generates a control signal when the measured Time intervals one through the maximum drift of the gyro and plus a safety surcharge fall below the given time interval and that switching means (36) are provided, when the signal of the element (32) occurs and when the vehicle movement occurs signals indicating that the feed (8 ') is blocked. 5. Arrangement for performing the method according to claim 1, characterized characterized in that on the precession axis of the course gyro (1) a torque transmitter (43) is attached in the absence of signals indicating the vehicle's movement of the transducer (2 ') is applied with a current (i) dimensioned such that thereby a precession speed around the azimuth axis (44) somewhat greater than the emigration speed is reached at maximum drift that switching means (in 1 ') are provided, which in the event of a predetermined change in the orientation of the Heading gyro (1 ') generate a control signal in each of the two directions of rotation, that a pole changer (42) is switched into the power supply of the torque transmitter (43) the polarity of which is reversed by each control signal and thereby leads to precession caused in the opposite direction, and that switching means (5 ', 40) are provided, the current (i) when a signal indicating vehicle movement occurs interrupt the displacement encoder (2 ') again. 6. Arrangement according to one of claims 1 - 4, characterized in that that measuring and calculating means are provided in order to determine from the drift values by which the angle & K is to be corrected and the holding time in which this angle change accrued is to determine the unknown drift fraction in angular degrees / per unit of time in order to Subsequently, directly or after evaluation with an evaluation factor z 1 to take into account the course determination. 7. Arrangement according to claim 5, characterized in that measuring and Computing means are provided to make up the occurred during the vehicle stop Duty cycle through the ratio of the times of the pendulum in the one and the other direction of rotation is given, the unknown gyro drift in angular degrees to be determined per unit of time in order to follow this up directly or after evaluation to be taken into account with an evaluation factor <1 when determining the course.