JPH11241926A - Traveling distance correcting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traveling distance correcting device capable of precisely and successively correcting the detection error of the traveling distance detecting means of a vehicle. SOLUTION: The polarity pattern of magnetic nails N arranged at prescribed intervals within a correcting section having a prescribed length provided on a road is different from the polarity pattern of magnetic nails N arranged in the other section, and the magnetic nails N are detected by a magnetic sensor 6, whereby the correcting section is discriminated from the other section. While a vehicle is passing the correcting section, a traveling distance detecting means 43 detects a traveling distance D on the basis of the pulse outputted by a wheel pulse sensor 8. A correcting means 44 compares the traveling distance D with the known length of the correcting section, and corrects the traveling distance D on the basis of the length of the correcting section when an error is present between the both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling distance correcting device for a vehicle for correcting an error of a traveling distance detecting means for detecting a traveling distance based on the number of rotations of a wheel.

[0002]

2. Description of the Related Art A traveling distance of a vehicle is detected by detecting a plurality of detected protrusions provided on an outer periphery of a rotor rotating integrally with wheels and a plurality of detected protrusions provided on an outer periphery of a rotor arranged in a power transmission system from an engine to wheels. The detection is carried out by detecting the detected projections with a magnetic pickup. That is, one pulse output from the magnetic pickup corresponds to rotation of the wheel at a predetermined angle,
The traveling distance of the vehicle can be calculated by knowing the integrated value of the output pulse and the circumference of the wheel.

[0003]

Since the circumference of the wheel changes depending on the tire pressure and the degree of wear of the tire, the traveling distance detected by the conventional traveling distance detecting means may have an error. Moreover, since the air pressure of the tire and the degree of wear of the tire change over time, it is necessary to sequentially correct the detection error of the traveling distance detecting means.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a vehicle traveling distance correction device capable of accurately and sequentially correcting a detection error of a vehicle traveling distance detecting means. I do.

[0005]

In order to achieve the above object, an invention according to claim 1 is provided with a plurality of magnetic sources arranged at a predetermined interval on a traveling route of a vehicle, and provided on the vehicle. Magnetic detecting means for detecting the magnetic source, a traveling distance detecting means provided in the vehicle for detecting a traveling distance based on the number of rotations of wheels, and a correction for correcting the traveling distance detected by the traveling distance detecting means. Means, the polarity pattern of the magnetic source arranged in the correction section of a predetermined length provided on the traveling route of the vehicle is different from the polarity pattern of the magnetic source arranged in another section. The correction means detects the correction section based on the output of the magnetic detection means, and the correction means detects the travel distance detected by the travel distance detection means while the vehicle travels in the correction section. The predetermined Compared To be and corrects the traveling distance.

According to the above arrangement, when the magnetic detecting means detects a plurality of magnetic sources arranged at a predetermined interval on the traveling route, the magnetic detecting means disposed within the correction section of a predetermined length on the traveling route. Since the polarity pattern of the source is different from the polarity pattern of the magnetic source arranged in the other section, the correcting means can identify the correction section from the other section. Then, the correction means compares the traveling distance detected by the traveling distance detection means based on the number of rotations of the wheels with a predetermined length of the known correction section while the vehicle passes through the correction section, and an error between the two is obtained. If so, the traveling distance is corrected based on the predetermined length.

In this manner, by making the polarity patterns of the magnetic sources arranged on the traveling route at predetermined intervals different in the correction section of the predetermined length, it is detected that the vehicle is traveling in the correction section, Since the traveling distance detected by the traveling distance detecting means based on the number of rotations of the wheels is compared with the known predetermined length, the detection error of the traveling distance detecting means can be accurately corrected. Moreover, it is possible to sequentially correct the detection error of the traveling distance detecting means only by providing a correction section at an arbitrary position on the traveling route of the vehicle.

The predetermined interval at which a plurality of magnetic sources are arranged is 1 m in the embodiment, but the predetermined interval is a value that can be arbitrarily set as required. The predetermined length of the correction section is 500 m in the embodiment, but can be set arbitrarily as long as the polarity pattern of the plurality of magnetic sources arranged therein can be identified.

Further, since the traveling distance per unit time is synonymous with the traveling speed, the vehicle traveling distance correction device of the present invention detects the traveling speed based on the number of rotations of the wheels per unit time, and determines the traveling speed. It includes a vehicle traveling speed correction device for correcting the speed.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the traveling distance detecting means detects a traveling distance by counting pulses output with rotation of the wheels. The correction means corrects a distance conversion value per unit pulse by comparing the travel distance with the predetermined length.

According to the above configuration, not only can the traveling distance be detected with a simple configuration that only counts the pulses output as the wheels rotate, but also the distance conversion value per unit pulse is corrected. The traveling distance can be easily and reliably corrected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 5 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a vehicle, FIG. 2 is an explanatory diagram of a magnetic nail and a magnetic sensor, FIG. 3 is a block diagram of a control system, FIG.
FIG. 5 is a block diagram of a vehicle mileage correction device, and FIG. 5 is a diagram showing an arrangement pattern of magnetic nails in a correction section.

The present embodiment is intended for a vehicle that runs automatically on a road for automatic driving in which magnetic nails N as magnetic sources are embedded at predetermined intervals (for example, at intervals of 1 m) along the center of the lane. Things.

FIG. 1 shows the overall structure of the preceding vehicle V 'and the host vehicle V. Since the configuration of the preceding vehicle V 'and the configuration of the own vehicle V are substantially the same, the following description will be made using the own vehicle V as an example.

The own vehicle V includes a communication signal processing means 1, a control plan processing means 2, a steering control means 3, and a vehicle speed control means 4 as modules each having a signal processing device (CPU) mounted thereon. I have.

The communication signal processing means 1 performs inter-vehicle communication between the vehicle V and the preceding vehicle V ', transmission and reception between the vehicle and the leaky coaxial cable C provided along the road, The calculation of the own vehicle position is performed. The road data consists of data of magnetic nail rows (traveling lines) on the map.
This may be stored in a storage device in advance, or may be received from outside for each predetermined traveling area by communication.

The control plan processing means 2 creates information for automatic traveling by operating the automatic traveling start switch 12. Specifically, based on the speed command received from the leaky coaxial cable C, a vehicle speed plan is created along the magnetic nail array, and the current position deviation (error) and the direction deviation (error) with respect to the magnetic nails N immediately below the vehicle V are determined. ), And a positional deviation (error) and a direction deviation (error) of the predicted arrival point after a predetermined time T seconds from the magnetic nails N. This calculation result is used for steering control of the own vehicle V, and
Is used to correct the acceleration / deceleration of the vehicle. In the present embodiment, the predetermined time is set to 1.5 seconds, but it is preferable to set the time between 1 second and 2 seconds. In the case of a following vehicle that follows the preceding vehicle V ′, the inter-vehicle distance and the inter-vehicle speed difference between the expected arrival point T seconds after the own vehicle and the expected arrival point T seconds after the preceding vehicle V ′ are also calculated. The calculation result is used for correcting the acceleration / deceleration of the vehicle V.

Further, in the case of a following vehicle, the control plan processing means 2 displays data such as the speed of the own vehicle and the speed of the preceding vehicle, the inter-vehicle distance to the preceding vehicle, the shape of the road ahead, the shape of the lane, and the like. 17 is output. In the case of the preceding vehicle, data such as the own vehicle speed and the speed of the following vehicle, the inter-vehicle distance to the following vehicle, the shape of the road ahead and the shape of the lane are output to the display 18 and the speaker 17.

The steering control means 3 calculates a steering angle instruction signal based on the output result of the control plan processing means 2 and controls the actuator 14 provided in the steering operation transmission system. The steering is automatically controlled by the actuator 14, and the vehicle travels along the magnetic nail array.

The vehicle speed control means 4 calculates an acceleration instruction signal based on the vehicle speed plan of the control plan processing means 2 and a sensor signal described later, and controls an actuator 15 provided on the throttle and an actuator 16 provided on the brake. I do. By these two actuators 15, 16,
The throttle and the brake are driven to accelerate and decelerate the vehicle V. A brake pedal switch 13 is connected to the vehicle speed control means 4. When it is detected that the brake pedal 13 is depressed, the vehicle speed control is released.

The own vehicle V has a yaw rate sensor 5
A magnetic sensor 6 for detecting magnetic nails N embedded in the road surface, a wheel pulse sensor 8, a longitudinal acceleration sensor 9, a laser radar 10, and a communication means 7 for transmitting and receiving to and from the leaky coaxial cable C. , An inter-vehicle communication unit 11.

Speed command information, road curvature information, traffic congestion information, an emergency message and the like are received from the leaky coaxial cable C, and the ID number of the own vehicle V is transmitted from the own vehicle V side. From the ID number, the traveling position of each vehicle is grasped on the leaky coaxial cable C side.

In the vehicle-to-vehicle communication, travel distance, vehicle speed and longitudinal acceleration data (control plan data) are transmitted and received. In the case of a following vehicle, the position and running state (speed and acceleration) of the preceding vehicle are detected by this inter-vehicle communication, and are used for creating correction data for following control.

The yaw rate sensor 5 detects the lateral angular velocity of the vehicle, and outputs a detection signal to the communication signal processing means 1, the control plan processing means 2, and the steering control means 3.

The magnetic sensor 6 as a magnetism detecting means is provided below the front bumper and the rear bumper of the vehicle.
The sensor position (vehicle position) with respect to the magnetic nails N provided on the lane of the road at intervals of 1 m is measured within a range of about 45 cm left and right from the center of the magnetic nails N. In the present embodiment, as shown in FIG. 2, a magnetic sensor 6 is provided at a lower part of a front bumper and a lower part of a rear bumper of a vehicle. The angle (error angle) with the vehicle V is also detected. The traveling distance D of the vehicle is detected by counting the output of the magnetic sensor 6, and the vehicle speed is detected by counting the output of the magnetic sensor 6 per unit time or by differentiating the traveling distance D with time. You.

The wheel pulse sensor 8 is used for detecting the traveling distance D and the vehicle speed of the vehicle. It is assumed that magnetic detection cannot be performed only by detecting the traveling distance D and the vehicle speed by the magnetic sensor 6, for example, when the vehicle greatly deviates from the planned traveling lane. In such a case, the wheel pulse sensor 8 is used. The traveling distance D and the vehicle speed detected by the wheel pulse sensor 8 are inevitably generated due to a change in the diameter due to, for example, the air pressure of the wheel. It is corrected using the output. The details will be described later.

The longitudinal acceleration sensor 9 is used for detecting the longitudinal acceleration of the vehicle. Although the longitudinal acceleration of the vehicle can be obtained from the output signal of the magnetic sensor 6, the longitudinal acceleration is used for detecting the longitudinal acceleration when, for example, the vehicle deviates greatly from the planned lane and the magnetic field cannot be detected.

The laser radar 10 detects the preceding vehicle V 'and the obstacle ahead, calculates the distance to those objects, and outputs the distance to the vehicle speed control means 4. Based on this output, the vehicle speed control means 4 controls the brake amount according to the situation. Although the position of the preceding vehicle V 'can be obtained from the inter-vehicle information, the mounting of the laser radar 10 can more reliably detect the preceding vehicle V' and calculate the inter-vehicle distance.

Next, the operation of the embodiment of the present invention will be described with reference to the block diagram of FIG.

First, the target acceleration of the vehicle V is calculated as follows. That is, the control plan processing means 2 controls the vehicle position X based on the detection signal from the magnetic sensor 6.
_i (0) 21 and own vehicle speed (first order differential value of own vehicle position) V
_i (0) 22 and own vehicle acceleration (second order differential value of own vehicle position)
A _i (0) 23 is calculated and output to the first processing unit 24 of the vehicle speed control means 4 for predicting the state of the vehicle V after T seconds.

The first processing unit 24 calculates a predicted position X _i (T) after T seconds and a predicted speed V _i (T) after T seconds by the following equations.

X _i (T) = X _i (0) + V _i (0) × T
+ 1/2 × A _i (0) × T ² V _i (T) = V _i (0) + A _i (0) × T On the other hand, the control plan processing unit 25 of the control plan processing means 2 Based on the speed command, a vehicle speed plan along the magnetic nail array is created, and the target position X _i ′ after T seconds has elapsed.
(T) and the target speed V _i ′ (T).

In the deviation calculating means 50, the control plan processing unit 2
From the target position X _i ′ (T) and the target speed V _i ′ (T) calculated in step 5, the distance X _i (T) and the speed V _{i are obtained.}
By subtracting (T), a position error and a speed error are calculated respectively.

The position error and the speed error are added after being multiplied by the acceleration control gains Kx and Ku in the control plan data converter 26, and are output to the comparator 27 as the target acceleration. That is, the target acceleration is given by the following equation.

Target acceleration = Kx × ｛X _i '(T) -X _i
(T)｝ + Ku × {V _i '(T) -V _i (T)} On the other hand, the position data X _{i-1 of the} preceding vehicle V' by the inter-vehicle communication.
(0) 28, speed data (differential value of preceding vehicle position) Vi _-1
(0) 29 and acceleration data (second-order differential value of the position of the preceding vehicle) A _i-1 (0) 30 are output to the second processing unit 31 for predicting the state of the preceding vehicle V ′ after T seconds. .

In the second processing unit 31, the first processing unit 2
4, the predicted position X _i-1 (T) of the preceding vehicle V ′ after T seconds and the predicted speed V after T seconds
_i-1 (T) is calculated. The deviation calculating means 40 calculates a predicted position X of the subject vehicle V after T seconds from the predicted position X _i-1 (T) and the predicted speed V _i-1 (T) of the preceding vehicle V '.
By subtracting _i (T) and the predicted speed V _i (T), an inter-vehicle distance as a distance deviation and an inter-vehicle speed as a speed deviation are calculated.

A target inter-vehicle distance adjusting means 32 is provided to correct the inter-vehicle distance according to the own vehicle speed V _i (0) 22. This is used for adjusting the speed during the initial period of driving or during the period of ending the driving. When the inter-vehicle distance is set to a proportional value of the speed, it corrects for the approaching at low speed. Depending on how you set the following distance,
This target inter-vehicle distance adjusting means 32 becomes unnecessary.

The calculated inter-vehicle distance and inter-vehicle speed are converted into acceleration control gains Kx ₁ , Kx
After being multiplied by u ₁ , the sum is added and the target acceleration is calculated as in the following equation.

Target acceleration = Kx ₁ × ｛X _i-1 (T) -X
_i (T)｝ + Ku ₁ × {V _i-1 (T) -V _i (T)} The target acceleration is output to the comparison unit 27. Comparison section 27
Then, the target acceleration based on the predicted deviation of the self-vehicle V after T seconds is compared with the target acceleration based on the inter-vehicle distance and the inter-vehicle speed with the preceding vehicle V ′. Is selected and output to the throttle-side integrator 41 and the brake-side integrator 42 as correction data. The integrated value of the corrected data is output to the throttle control amount conversion means 34 and the brake control amount conversion means 35, and the throttle control unit 36 and the brake control unit 37 output the instruction duty to the throttle actuator 15 and the brake actuator 16, respectively. To perform feedforward control.

In the comparison section 27, for example, on the preceding vehicle V 'side, the correction data on the conversion means 26 side is output, and the own vehicle (following vehicle) is output.
On the V side, the correction data of the conversion means 33 may be output.

The steering control means 3 (see FIG. 1) calculates the displacement of the vehicle position from the magnetic nails N and the displacement angle in the vehicle traveling direction with respect to the tangent to the line to be traveled based on the current position reception curvature signal from the leaky coaxial cable C. And the position error between the target point and the predicted arrival point at a predetermined distance ahead calculated from the road shape (road curvature) data in the front of the route data, and the displacement angle in the vehicle traveling direction from the planned traveling line. Based on the calculated values, the actuator 14 of the steering device is driven to cause the vehicle V to travel along the magnetic nail array (traveling line).

Next, the correction of the traveling distance D of the vehicle detected by the wheel pulse sensor 8 will be described.

As shown in FIG. 4, a plurality of (for example, eight) rotors 41 are arranged at equal intervals on the outer periphery of the rotor 41 which rotates integrally with the wheels W.
Are provided, and the wheel pulse sensor 8 is provided so as to face the detected protrusions 42. The traveling distance detection means 43 detects the traveling distance D of the vehicle based on the number of pulses input from the wheel pulse sensor 8. Since eight pulses are detected for one rotation of the wheel W, if the circumference of the wheel W is 2 m, the traveling distance D of the vehicle per pulse is 0.25 m.

As shown in FIG. 5, a predetermined length L
Correction sections (for example, 500 m) are provided at appropriate intervals. The magnetic nails N arranged at 1 m intervals on the road have polarities of N pole and S pole, respectively. The polarity pattern of the magnetic nails N arranged in the correction section is the same as the polarity pattern of another section. By making them different, it is possible to detect whether or not the vehicle V is currently traveling in the correction section based on the output of the magnetic sensor 6.

Returning to FIG. 4, the correction means 44 connected to the magnetic sensor 6 and the wheel pulse sensor 8
The number of pulses input from the wheel pulse sensor 8 is counted while the own vehicle V is traveling in the correction section according to the signal from. If the circumference of the wheel W is correctly 2 m, the number of pulses detected while the vehicle travels in the correction section of 500 m is 2
If the circumference is 2 m or more due to the air pressure or the degree of wear of the wheel W, the number of detected pulses becomes 2000 pulses or less, and the travel distance detecting means 4
3 is less than the actual traveling distance. Conversely, if the circumference of the wheel W is 2 m or less, the number of detected pulses is more than 2000 pulses and is detected by the traveling distance detecting means 43. The traveling distance D is equal to or longer than the actual traveling distance.

That is, assuming that the traveling distance per pulse is A and the number of pulses detected during traveling in the correction section is P, A × P = L holds, so that the traveling distance A per pulse is A = L / P. In the embodiment, if the traveling distance A per pulse is 0.25 m, the traveling distance D detected by the traveling distance detecting means 43 is accurate and does not need to be corrected. If it is deviated from 0.25 m, the traveling distance D detected by the traveling distance detecting means 43 is corrected by the correcting means 44 according to the ratio. This makes it possible to correct a detection error of the traveling distance detecting means 43 caused by a change in the circumference of the wheel W, and to detect a correct traveling distance D. Moreover, it is possible to sequentially correct the detection error of the traveling distance detecting means 43 only by providing correction sections on the road at appropriate intervals.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, the detected protrusions 42 provided on the rotor 41 rotating integrally with the wheel W are detected. However, the detected protrusions 42 are provided on a rotating member such as a gear provided on a power transmission system from the engine to the wheels. It is also possible to detect the detection protrusions 42. In addition, the mileage correction device of the present invention is used for
That is, the present invention can be applied to an inertial navigation device or the like of a navigation system.

[0050]

As described above, according to the first aspect of the present invention, the polarity patterns of the magnetic sources arranged at predetermined intervals on the traveling route are made different in the correction section of the predetermined length to thereby provide the vehicle with the vehicle. Detects that the vehicle is traveling in the correction section, and compares the traveling distance detected by the traveling distance detecting means based on the number of rotations of the wheels with the known predetermined length. Can be accurately corrected. Moreover, it is possible to sequentially correct the detection error of the traveling distance detecting means only by providing the correction section at a predetermined position on the traveling route of the vehicle.

According to the second aspect of the present invention,
Not only can the running distance be detected with a simple configuration that only counts the pulses output with the rotation of the wheels, but also the distance conversion value per unit pulse is corrected, so the running distance can be corrected easily and reliably. It can be carried out.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle.

FIG. 2 is an explanatory diagram of a magnetic nail and a magnetic sensor.

FIG. 3 is a block diagram of a control system.

FIG. 4 is a block diagram of a vehicle mileage correction device.

FIG. 5 is a diagram showing an arrangement pattern of magnetic nails in a correction section.

[Explanation of symbols]

 D Travel distance L Predetermined length N Magnetic nail (magnetic source) V Own vehicle (vehicle) W Wheel 6 Magnetic sensor (magnetic detection means) 43 Travel distance detection means 44 Correction means

Claims (2)

[Claims] 1. A plurality of magnetic sources (N) arranged at predetermined intervals on a traveling route of a vehicle (V), and magnets provided on the vehicle (V) for detecting the magnetic sources (N). Detecting means (43) provided on the vehicle (V) for detecting the running distance (D) based on the number of rotations of the wheels (W);
And a correcting means (44) for correcting the running distance (D) detected by the running distance detecting means (43), wherein a predetermined length (L) provided on the running route of the vehicle (V) is provided. By making the polarity pattern of the magnetic source (N) arranged in the correction section of the first section different from the polarity pattern of the magnetic source (N) arranged in the other section, the correction means (44)
Detects the correction section based on the output of the magnetism detection means (6), and the correction means (44) controls the travel distance detection means (43) while the vehicle (V) travels in the correction section. A travel distance correcting device for a vehicle, wherein the travel distance (D) detected in step (D) is compared with the predetermined length (L) to correct the travel distance (D). 2. The traveling distance detection means (43) detects a traveling distance (D) by counting pulses output with rotation of a wheel (W), and the correction means (44) The travel distance correction device for a vehicle according to claim 1, wherein the distance conversion value per unit pulse is corrected by comparing the travel distance (D) with the predetermined length (L).