JPH0418776B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a traveling distance/turning angle detection device. More specifically, the present invention relates to a traveling distance/turning angle detection device, and more specifically, it is capable of accurately measuring the traveling distance and turning angle of a vehicle even if the wheels and road surface slip. The present invention relates to a travel distance/turning angle detection device that can detect travel distance and turning angle.

[Conventional technology]

In recent years, with the rapid development of electronic technology, various devices have been developed to assist vehicle driving, one of which is a travel trajectory display device.

This travel trajectory display device provides road guidance by displaying the vehicle travel trajectory on a display map. The traveling trajectory of the vehicle is determined by aligning the current position display spot with the corresponding position on the display map at the start of traveling, and then determining the vehicle's trajectory based on the relationship between the traveling distance from the starting point and the turning angle of the vehicle. This is done by finding the current position and displaying it sequentially. The inventor of the present application has recently developed a running distance/turning angle detection device that can accurately detect the running distance and turning angle of this running trajectory display device with a simple configuration. Since the present invention mainly relates to the improvement of this traveling distance/turning angle detecting device, first, its specific structure and operation will be explained with reference to FIG. 2.

In the figure, wheels 3a and 3b are fixed to the tips of axles 2a and 2b at the rear of the vehicle that extend from a differential gear 1 in both directions. The conventional travel distance/turn angle detection device includes rotation detection sections 4a and 4b that generate rotation angle pulses every time a unit rotation angle of wheels 3a and 3b is detected, and rotation detection sections 4a and 4.
waveform shaping circuits 5a, 5b that adjust the waveform of the rotation angle pulse output from b; and waveform shaping circuits 5a, 5
A counter 6 that counts the number of rotation angle pulses whose output waveforms have been shaped from b and outputs a cumulative count signal.
a, 6b, and the cumulative count signals output from the counters 6a, 6b, and perform calculation processing on the traveling distance data and traveling direction data, and output ports P1,
Output from P2 and counter 6 in the initial state
A microcomputer 7 outputs from an output port P3 a reset signal for clearing the count values of a and 6b.

The rotation detecting parts 4a, 4b are provided with gear-like pulsers 8a, 8b having N teeth mounted on the axles 2a, 2b, respectively, and placed close to the peripheral surfaces of the pulsers 8a, 8b to magnetically prevent the passage of the toothed parts. Magnetic sensor 9 to detect
a and 9b.

In the conventional traveling distance/turning angle detecting device having the above structure, the microcomputer 7 generates a reset signal during initial operation to clear the counts of the counters 6a and 6b. Next, when the vehicle starts traveling straight, the pulsar 8 rotates simultaneously with the rotation of the wheels 3a and 3b.
a and 8b also rotate. And this Pulsar 8
When a and 8b rotate, the teeth provided on their peripheral surfaces pass just in front of the magnetic sensors 9a and 9b, so the magnetic characteristics change and a rotation angle pulse is generated. Then, this double rotation detection section 4
After the rotation angle pulses generated from a and 4b are waveform-shaped in waveform shaping circuits 5a and 5b,
The signals are supplied to counters 6a and 6b and counted.

Here, when the vehicle is traveling straight, the cycles of the rotation angle pulses generated from the rotation detection units 4a and 4b are the same, but when the vehicle turns, the difference between the inner and outer wheels of the wheels 3a and 3b Therefore, the amount of rotation of the wheels located on the inside is reduced. For example, since the amount of rotation of the wheel 3a decreases, the period of the rotation angle pulse generated from the rotation detection section 4a that detects the rotation of the wheel 3a becomes the period of the rotation angle pulse generated from the other rotation detection section 4b. It will be longer than Therefore, the amount of turning of the vehicle is expressed as the difference between the cumulative counts of the counters 6a and 6b.

[Problem to be solved]

As described above, the conventional traveling distance/turning angle detection device calculates the traveling distance and the turning angle by counting the rotation angle pulses generated in response to the rotation of both the left and right wheels.

The determined travel distance and turning angle are supplied to, for example, the display section of a travel distance display device to sequentially determine the current position, and the current position display spot on the display map is moved in accordance with this current position information. As a result, the traveling trajectory was displayed accurately, and a traveling distance/turning angle detection device of a traveling trajectory display device with a simpler configuration was obtained, but there were still some technical issues to be improved. One of them is described below.

That is, even if the wheels and the road surface slip, rotation angle pulses are counted, which naturally causes errors in travel distance data and turning angle data, and errors are naturally included in current position information, so it is difficult to accurately detect the current position. There was a problem that it was not possible.

This invention has been made to solve the above problems, and provides a travel distance/turn angle detection device that can accurately detect the travel distance and turning angle of a vehicle even if the wheels and the road surface slip. The purpose is to provide the following.

[Means for solving problems]

In order to achieve the above object, the traveling distance/turning angle detecting device of the present invention detects the rotational speed of each of the left and right wheels and the rotational speed difference between them in a vehicle having both left and right wheels that are not fixedly connected to a single shaft. A travel distance/turning angle detection device that cumulatively displays the travel distance and travel direction of the vehicle, a slip detection unit that detects slip on one and/or the other of both left and right wheels and outputs a slip signal, and a slip detection unit that outputs a slip signal from the slip detection unit. The present invention has a structure that includes a holding section that receives a slip signal and holds the vehicle traveling direction and vehicle traveling distance immediately before the slip.

[Effect]

As described above, in the traveling distance/turning angle detecting device of the present invention, the slip detection section detects a slip between one or both of the right and left wheels and the road surface and outputs a slip detection signal, and the holding section detects a slip between the left and right wheels or both wheels and the road surface. In response to the slip signal output from the slip detection section, the vehicle running direction immediately before the slip is maintained.

〔Example〕

Next, embodiments of the invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the traveling distance/turning angle detecting device of the present invention. In the figures, the same reference numerals or symbols as those described above represent the same or equivalent parts, and explanations of the configuration and operation will be omitted as appropriate.

Numeral 8 is a slip detection section, and numeral 9 is a holding section, which are newly added to the conventional traveling distance/turning angle detection device (Fig. 2).The configuration of the other parts is the same as that explained in Fig. 2. It's the same. However, the present invention is not limited to this, and can be applied to all systems that detect changes in wheel rotation.

The slip detection section 8 includes waveform shaping circuits 5a and 5b.
It is comprised of slip detection circuits 8a and 8b which receive rotation angle pulses outputted from the rotation angle pulses, detect slips, and output slip signals.

The holding unit 9 is an OR circuit 9a that receives the slip signals output from the slip detection circuits 8a and 8b and logically adds both signals.When one or both wheels slip at the same time, the holding unit 9 holds the slip signal and outputs the slip signal to the microcomputer 7. Input to port P4. When the microcomputer 7 receives the slip signal, it interrupts the calculation process and outputs the result of the calculation process immediately before receiving the slip signal.

Therefore, in the traveling distance/turning angle detection device of the above embodiment, the difference between the inner and outer wheels due to the turning angle is calculated from the cumulative count value of the cumulative count value obtained by counting the rotation angle pulses generated in response to the rotation of both the left and right wheels. The travel distance and turning angle of the vehicle will be determined with high precision. Furthermore, if one or both of the wheels slips on the road surface while driving, the slip detection unit detects the slip, and the holding unit maintains the travel distance and turning angle just before the slip. Even if this occurs, the travel distance and turning angle can be accurately detected.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the traveling distance/turning angle detection device of the present invention, and FIG. 2 is a construction block diagram of a conventional traveling distance/turning angle detection device. 3a, 3b...Both left and right wheels, 8...Slip detection section, 9...Holding section.

Claims (1)

[Scope of Claims] 1. In a vehicle having left and right wheels that are not fixedly connected to a single shaft, a travel distance that cumulatively displays the travel distance and travel direction of the vehicle from the respective rotational speeds of the left and right wheels and the rotational speed difference between them. - a turning angle detection device, a slip detection section that detects slip on one and/or the other of the left and right wheels and outputs a slip signal, and receives the slip signal output from the slip detection section and determines the vehicle running direction immediately before the slip. A travel distance/turning angle detection device comprising: and a holding portion that holds a vehicle travel distance.