JP2002196819A - Autonomous straight advance device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the autonomous straight advance device of an autonomous traveling vehicle capable of highly precisely operating target azimuth setting in teaching traveling in a real work. SOLUTION: The block diagram of a target azimuth setting part in an autonomous straight advance device in a teaching mode is indicated in a figure 1. The calculation of a target azimuth ψtgt to be operated by a teaching managing part 41 in this figure 1 adopts a method for integrating the detected vehicle azimuth by the movement distance increment in the detection period of the azimuth, and for dividing the integrated value by a teaching distance St being the total movement distance. Thus, even when the vehicle stops during the teaching traveling, the vehicle azimuth data when the vehicle stops being the factor of an error can be removed from the basic data of the target azimuth calculation, and the calculation of the target azimuth can be highly precisely operated. Also, this device is provided with a speed sensor 8 and a steering angle sensor 11, and the steering state in which the vehicle azimuth being the factor of the error of the target azimuth calculation is detected can be judged from information obtained by those sensors, and the vehicle azimuth data in the improper steering state can be removed from the basic data of the target azimuth calculation. Thus, it is possible to highly precisely operate the calculation of the target azimuth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an azimuth sensor for detecting the azimuth of a vehicle, and arithmetic means for receiving the azimuth of the vehicle, calculating the sum of the azimuths of the vehicle, and converting the sum to a target azimuth. It relates to an autonomous straight-ahead device. As an application field of the present invention, a target direction setting function in an autonomous straight-ahead device of an autonomous vehicle using a direction sensor, for example, an agricultural tractor that autonomously performs cultivated land maintenance and rice planting work and a transportation that transports building materials at a construction site. A target azimuth setting function in an autonomous straight-ahead device such as a car is exemplified.

[0002]

2. Description of the Related Art A general configuration of a portion related to the traveling of an autonomous vehicle is a drive system for driving wheels, a steering system for changing the direction of wheels, and a steering direction sequentially changed according to a target direction under the control of a CPU. And an autonomous straight-ahead device to be controlled. This autonomous vehicle has three main driving modes. The vehicle is autonomously controlled while controlling the steering direction based on the mode in which the user performs teaching traveling by steering to determine the target direction (so-called teaching mode), and the target direction obtained in the teaching mode and the current direction of the vehicle. Autonomous traveling mode, and a standby mode in which the teaching traveling of the autonomous traveling vehicle and the autonomous traveling are not performed.

The details of the teaching mode will be described. The teaching mode refers to a mode in which a test run is performed by the user's steering, data used as a basis for calculating a target direction is acquired at that time, and a target direction is calculated based on the data. The target direction setting unit captures the data, calculates and holds the target direction, and provides the target direction and vehicle direction to the autonomous straight-ahead device during autonomous driving, and generally forms part of the autonomous straight-ahead device. It is. An example of a conventional target direction setting unit will be described with reference to FIG. FIG. 6 is a block diagram showing a configuration in a teaching mode in a conventional autonomous straight-ahead device including a target direction setting unit. In FIG. 6, a target direction setting unit includes a geomagnetic sensor 1 for detecting geomagnetism around a vehicle, an AD conversion circuit 2 for digitally converting a detection value of the geomagnetic sensor 1, and a digital signal output from the AD conversion circuit 2 in a predetermined manner. A direction calculation unit 3 for calculating and converting to a signal (hereinafter, referred to as a vehicle direction signal), and a teaching management unit 4 for calculating, storing and holding a target direction based on the vehicle direction signal calculated and converted at regular intervals and the number of the signals. Consists of A method of calculating the target direction in the teaching management unit 4 will be described. The vehicle azimuth signal transmitted to the teaching management unit 4 is integrated at regular intervals from the start of the teaching mode, and an average value obtained by dividing the obtained azimuth integrated value by the number of times of integration of the vehicle azimuth signal is used as the target azimuth. When the predetermined target direction can be acquired, the teaching mode shifts to the standby mode.

FIGS. 7 and 8 show an autonomous driving mode.
This will be described with reference to FIG. FIG. 7 is a diagram showing a relationship among various elements in the autonomous vehicle, and FIG. 8 is a block diagram showing a configuration in the autonomous traveling mode in the above-described autonomous straight traveling device.
The vehicle azimuth 16 in FIG. 7 represents an angle formed with the longitudinal axis of the vehicle 19 based on the magnetic north N. The terrestrial magnetism around the vehicle sequentially detected by the terrestrial magnetism sensor 1 in FIG. The magnetic azimuth calculated by the arithmetic unit 3 is transmitted to the steering control arithmetic unit 5 as the vehicle azimuth 16. The steering angle 15 is an angle formed between the longitudinal axis of the vehicle and the rotation surface of the wheel 7, and is a steering angle changing device 6 provided in the steering system.
Is set freely by the user. Steering angle changing device 6
Is a manual control unit that normally changes the direction of the wheels 7 under the control of the user, and a steering control command 17 from the autonomous straight-ahead device.
The automatic control unit changes the direction of the wheels 7 according to the following. The automatic control unit of the steering angle changing device 6 operates the hydraulic actuator by controlling the flow rate of pressure oil supplied from a hydraulic source (not shown) by a steering control valve. This operation corresponds to the direction of the wheels 7, that is, the steering angle 15 via the steering mechanism in the steering angle changing device. The target direction 18 is represented by an angle based on magnetic north N similarly to the vehicle direction 16, and is acquired in the teaching mode.

[0005] The mechanism of autonomous traveling will be described. When the user presses the autonomous traveling switch 102 prior to the start of the autonomous traveling, the traveling mode is switched from the standby mode to the autonomous traveling mode, and the block configuration and the data flow are changed as shown in FIGS. That is, the vehicle azimuth 16 output from the azimuth calculation unit 3 in FIG. 6 and transmitted to the teaching management unit 4 is transmitted to the steering control calculation unit 5 at the same time as switching to the autonomous driving mode. At the same time, the target azimuth 18 stored in the teaching management unit 4 is also transmitted to the steering control calculation unit 5 as a set value.
FIG. 7 shows a state in which the vehicle direction 16 is shifted from the target direction 18 during autonomous traveling. The steering control calculation unit 5 determines that the azimuth to be advanced from the transmitted vehicle azimuth 16 and the set target azimuth 18 is deviated, and transmits a steering control command 17 which is a command for correcting the deviation to a predetermined control algorithm. And transmits it to the actuator drive amount calculation unit 22. As a control algorithm for calculating the steering control command 17, there is, for example, one utilizing PID control. The actuator drive amount calculation unit 22 includes a steering angle (FIG. 7) detected by the steering angle sensor 11 attached to the steering angle changing device of the steering system.
(Corresponding to the steering angle 15) is sequentially input as a digital signal through the AD conversion circuit 21. The actuator drive amount calculation unit 22 calculates an actuator drive amount. That is, the actuator drive amount corresponds to the steering change amount from the current steering angle in order to cause the steering angle to follow the input steering control command, and thus the steering control valve (not shown) constituting the steering angle changing device 6. It corresponds to the opening amount. Actuator drive amount is
It is input to the DA conversion circuit 23 from the CPU. DA conversion circuit 23
Converts the input actuator drive amount into an analog electric signal and transmits it to the actuator control circuit 24. The actuator control circuit 24 controls the steering control command 17 of the PWM signal so that the analogized actuator drive amount corresponds to the interface of the steering angle changing device 6.
And outputs it to the steering angle changing device 6. Steering angle changing device 6
Automatically controls the steering angle 15 indicated by the wheels 7 according to the steering control command 17 converted into the actuator drive amount, and causes the vehicle direction 16 to follow the target direction 18.

A description will be given of a traveling operation in the teaching mode and an input configuration for selecting the teaching mode and the autonomous traveling. The teaching switch 101 has a function of inputting that a teaching mode has been selected by a user operation, that is, a function of inputting start and end of teaching travel. The autonomous traveling switch 102 has a function of inputting selection of the autonomous traveling mode by a user operation, that is, a function of inputting start and end of autonomous traveling. The discrete input circuit 103 generates a binary signal (hereinafter referred to as an ON / OFF signal) for distinguishing between a state in which both switches are pressed (ON) and a state in which the switches are returned (OFF), and transmits the signal to the following processing blocks. It has the function of an output interface. The switch determination unit 104 monitors the state change before and after the switch is pressed and the change time of the ON / OFF signal of the teaching switch or the autonomous traveling switch transmitted from the discrete input circuit 103, and detects the chattering phenomenon specific to the switch. It has a function of removing, and alternately determining the switch state as shown by the chart K in FIG. 10 and the chart L in FIG. 11 (processing to make a transition to OFF if ON and to ON if OFF). The determination result is transmitted to the mode switching processing unit 105. In the mode switching processing unit 105, a signal for discriminating between the teaching mode, the autonomous driving mode and the standby mode based on the switch judgment result transmitted from the switch judgment unit 104 (hereinafter, a signal for discriminating each mode is sequentially referred to as a teaching mode signal, an autonomous driving mode signal) And a standby mode signal, which will be referred to as an internal mode signal when these are collectively described) and transmitted to the teaching management unit 4 and the steering control calculation unit 5. In addition, in order to smoothly perform the teaching mode and the autonomous driving mode, and to collectively manage inputs for switching between the two modes, a part of the target azimuth setting unit, a part of the input configuration, and the steering control calculation unit 5 include: C
It is configured in the PU. In addition, for safety reasons, the operation of the autonomous traveling switch 102 is not determined by the switch determination unit 104 until the target direction is calculated.

Referring to FIGS. 9, 10 and 11, an example of a traveling pattern in the teaching mode and the autonomous traveling mode, and the state of each switch and the state of the internal mode signal at that time will be described. FIG. 9 is a schematic diagram of a traveling pattern of an autonomous traveling vehicle, which is a pattern assuming reciprocating traveling on farmland.
The first reciprocating stroke is a teaching traveling section, and the second reciprocating stroke is an autonomous traveling section. FIG. 10 is a time chart showing an example of the state of the teaching switch and the transition state of the teaching mode signal corresponding to the teaching travel in FIG. Chart F shows ON of the teaching switch 101 input from the discrete input circuit 103.
/ OFF state. Chart K represents the state of the teaching switch determined by the switch determination unit 104. Chart G shows the state of the signal from the start to the end of traveling on the outward route and return route in the mode switching processing unit 105 in synchronization with the ON / OFF state of the chart K. The mode switching processing unit 105 performs a first ON / OFF operation for a series of ON / OFF (corresponding to the chart K) of the teaching switch 101 determined by the switch determining unit 104 according to a determination rule provided therein.
OFF is judged as the state from the start to the end of the outbound traveling, and 2
The second ON / OFF is determined to be a state from the start to the end of the return travel. Each of the determined strokes is added to the internal mode signal as additional information and transmitted to the teaching management unit 4 and the steering control calculation unit 5. FIG. 10 shows a case where the internal mode is the teaching mode, and the teaching mode signal on the outward path and the teaching mode signal on the return path are distinguished. As a result, the teaching management section 4 can store and hold the target direction 18 calculated in the teaching mode as a target direction on the outward path or a target direction on the return path.

FIG. 11 is a time chart showing an example of a transition state of the internal mode in the mode switching processing section 105. A chart H shows the ON / OFF state of the teaching switch 101 input from the discrete input circuit 103, and corresponds to the chart F in FIG. Chart I shows the ON / OFF state of the autonomous traveling switch 102 input from the discrete input circuit 103. Chart L represents the state of the autonomous traveling switch 102 determined by the switch determination unit 104. Chart J shows the state of the internal mode signal generated in synchronization with the ON / OFF state of both switches in the mode switching processing unit 105. Initially, ON / OFF signals corresponding to the forward path and the return path from the teaching switch 101 are input (chart H). In response to this, the mode switching processing unit 105 generates a signal (corresponding to the above-described teaching mode signal) for determining that the internal mode is the teaching mode, and transmits the signal to the teaching management unit 4 and the steering control calculation unit 5. Upon receiving the signal, the teaching management unit 4 recognizes that the internal mode is the teaching mode, and periodically reads the azimuth data, calculates the target azimuth 18 after the reading is completed, and stores and holds the target azimuth 18 on the outward path. Perform for each return trip. The steering control calculation unit 5 recognizes that the driving mode is the driving mode by the user's steering, and maintains a state in which the steering control command 17 is not output, that is, a standby state.

At time K, upon receiving the ON determination of the autonomous traveling switch 102, the internal mode shifts from the standby mode to the autonomous traveling mode. The mode switching processing unit 105 generates a signal indicating that the internal mode is the autonomous driving mode (corresponding to the above-described autonomous driving mode signal), and transmits the signal to the teaching management unit 4 and the steering control calculation unit 5. In response to the transmission of the signal, the teaching management unit 4 recognizes that the internal mode is the autonomous driving mode, and sets the stored target direction in each of the outward and return routes, and transmits it to the steering control calculation unit 5. The steering control calculation unit 5 calculates a steering control command 17 based on the target azimuth 18 and the vehicle azimuth 16 transmitted as the processing in the autonomous driving mode.
Is generated, and thereafter, predetermined steering control is performed.

[0010]

In the above-described method of calculating the target azimuth, a target azimuth error may occur as described below. That is, when the vehicle stops during the teaching travel, the stopped vehicle direction is also sequentially added as target direction calculation target data, and this may cause a target direction error. In addition, even when the moving speed changes due to acceleration or deceleration during traveling, unevenness occurs in the moving distance with respect to the vehicle azimuth detection cycle, and the vehicle azimuth detection points become uneven, which is likely to cause a target azimuth error. . In addition, when moving the vehicle to the teaching start point, the course needs to be modified by the user,
At this time, the steering angle is temporarily swung right and left by the steering of the user, and the steering angle and the vehicle azimuth may not be straight for a while to adjust the vehicle traveling direction even after reaching the teaching traveling start point. In this case as well, a vehicle azimuth greatly deviating from the target azimuth is detected, which causes a target azimuth error.

If these cases are applied to the case where the user performs the teaching mode at the same time as the planting operation with the rice transplanter, the following problems are assumed. In the planting work of rice planting, the vehicle is often stopped for machine adjustment, and the vehicle direction in the stopped state may be detected. In addition, since the speed of the vehicle is slower in the vicinity of the teaching mode start point and the end point than in the steady driving, the number of detected vehicle azimuths is larger than in the section where the vehicle is steadily driven, and the weight as the azimuth data is different in the section. . As a countermeasure, it is conceivable to oblige the user to travel at a constant speed including the prohibition of stopping the travel and to pass the vehicle at the steady speed even when reaching the target point as a constraint during operation so as to strictly perform the teaching travel. However, although this measure improves the accuracy of detecting the direction of the vehicle, it is difficult to plant seedlings easily and cannot be adopted in view of the necessity of replanting work later. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an autonomous vehicle that can accurately set a target direction in a teaching operation in actual work.

[0012]

The gist of the present invention to achieve the above object lies in the following inventions. [1] An orientation sensor (1) for periodically detecting the orientation (16) of a vehicle and an orientation (16) of the vehicle are transmitted, and a target orientation (18) is calculated based on the orientation (16) of the vehicle. A moving distance detecting means for detecting a moving distance in each detection cycle of the azimuth (16) of the vehicle, wherein the calculating means (41) comprises:
Receiving the travel distance, the azimuth (16) of the vehicle is integrated with the travel distance from the teaching travel start point to the end point to calculate an azimuth integral value, and from the teaching travel start point to the end point based on the travel distance. The autonomous straight-ahead device, wherein the target azimuth (18) is obtained by calculating the total travel distance of the target azimuth and dividing the azimuth integral value by the total travel distance.

[2] mounted on a vehicle having a steering mechanism,
An azimuth sensor (1) for periodically detecting the azimuth (16) of the vehicle, and an operation for receiving the azimuth (16) of the vehicle and calculating a target azimuth (18) based on the azimuth (16) of the vehicle. A moving distance detecting means for detecting a moving distance in each detection cycle of the azimuth of the vehicle, and a steering angle for detecting a steering angle according to steering by the steering mechanism. A sensor (11), wherein the calculating means (41) receives the movement distance and the steering angle, and integrates the azimuth (16) of the vehicle with the movement distance from a teaching travel start point to an end point. Calculate the azimuth integral value by integral operation, calculate the sum of the travel distances by adding the travel distances from the teaching travel start point to the end point, and divide the azimuth integral value by the total sum of the travel distances. As the target direction (18) And determining whether or not the steering angle exists in a predetermined range, and interrupting the integration operation and the addition of the moving distance during a period in which it is determined that the steering angle does not exist in the predetermined range. And an autonomous straight-ahead device.

[3] The arithmetic means (41) holds a value immediately before the interruption in the integration operation as an integral value, holds a value immediately before the interruption in the addition as an addition value, and When it is determined that is within a predetermined range, restart the integration operation and the addition of the moving distance,
The moving distance after the restart is added to the added value immediately before the interruption to obtain a new added value, and the azimuth (16) of the vehicle after the restart is added to the integrated value immediately before the interruption. Adding a value obtained by partially integrating the moving distance to form a new integral value, the latest new integral value as the azimuth integral value,
The autonomous straight-ahead device according to [2], wherein the latest new added value is the sum of the moving distances.

[4] mounted on a vehicle having a steering mechanism,
An azimuth sensor (1) for periodically detecting the azimuth (16) of the vehicle, and an operation for receiving the azimuth (16) of the vehicle and calculating a target azimuth (18) based on the azimuth (16) of the vehicle. A moving distance detecting means for detecting a moving distance in each detection cycle of the azimuth of the vehicle, and a steering angle for detecting a steering angle according to steering by the steering mechanism. A sensor (11), wherein the calculating means (41) receives the movement distance and the steering angle, and integrates the azimuth (16) of the vehicle with the movement distance from a teaching travel start point to an end point. Calculate the azimuth integral value by integral operation, calculate the sum of the travel distances by adding the travel distances from the teaching travel start point to the end point, and divide the azimuth integral value by the total sum of the travel distances. As the target direction (18) The calculating means (41) determines whether or not the steering angle is within a predetermined range for a predetermined period, and determines that the steering angle is not within the predetermined range over the predetermined period. The autonomous straight-ahead device, wherein the integration operation and the addition of the moving distance are interrupted during a period.

[5] The arithmetic means (41) holds a value immediately before the interruption in the integration operation as an integral value, holds a value immediately before the interruption in the addition as an addition value, and When the calculating means (41) determines that the value is within the predetermined range beyond the predetermined period, the integration operation and the addition of the moving distance are restarted, and the added value immediately before the interruption is returned. Is added to the moving distance after the restart to obtain a new added value, and a value obtained by partially integrating the integral (16) of the vehicle after the restart with the moving distance after the restart to the integral value just before the interruption. [4], wherein a new integral value is added by adding a new integral value, the latest new integral value is used as the azimuth integral value, and the latest new added value is the sum of the moving distances. Autonomous straight-ahead device.

[6] The moving distance detecting means detects a rotation angle of a wheel of the vehicle at a predetermined resolution and converts the rotation angle into a pulse signal, and a pulse number of the pulse signal. A counter circuit (81) for counting and converting the accumulated pulse signal into an integrated pulse signal, a vehicle speed calculating section (9) for periodically reading out the integrated pulse signal and converting it into a vehicle speed signal, and a readout by the vehicle speed calculating section (9). The autonomous straight-line device according to any one of [1] to [5], further including: a moving distance calculating unit (10) that receives the integrated pulse signal and converts the integrated pulse signal into the moving distance.

[7] An azimuth sensor (1) for periodically detecting the azimuth (16) of the vehicle and the azimuth (16) of the vehicle are transmitted, and the target azimuth (1) is determined based on the azimuth (16) of the vehicle.
A vehicle speed sensor (8) for detecting a rotation angle of a wheel of the vehicle with a predetermined resolution and converting the rotation angle into a pulse signal; A counter circuit (81) for counting the number of pulses of the pulse signal and converting the integrated pulse signal into an integrated pulse signal; a vehicle speed calculating unit (9) for periodically reading the integrated pulse signal and converting the integrated pulse signal into a vehicle speed signal; A moving distance calculating unit (10) for transmitting the integrated pulse signal read in 9) and converting the integrated pulse signal into the moving distance;
Receives the vehicle speed signal and the travel distance, calculates an azimuth integral value by an integral operation of integrating the azimuth (16) of the vehicle with the travel distance from the teaching travel start point to the end point,
The sum of the travel distances is calculated by adding the travel distances from the teaching traveling start point to the end point, and a value obtained by dividing the azimuth integral value by the total sum of the travel distances is the target azimuth (18).
It is determined whether or not the vehicle speed has reached a predetermined speed, and during the period in which it is determined that the vehicle speed has not reached the predetermined speed, the integration calculation and the addition of the moving distance are interrupted. And an autonomous straight-ahead device.

[8] The arithmetic means (41) holds the value immediately before the interruption in the integration operation as an integral value, holds the value immediately before the interruption in the addition as an added value, and When the calculating means (41) determines that the predetermined speed has been reached, the integral calculation and the addition of the moving distance are restarted, and the moving distance after the restart is added to the added value immediately before the interruption. To a new added value, and to the integrated value immediately before the interruption,
A value obtained by partially integrating the azimuth (16) of the vehicle with the moving distance after the restart is added to obtain a new integrated value, the latest new integrated value is used as the azimuth integrated value, and the latest new added value is used. Is the sum of the moving distances, the autonomous straight-ahead device according to [7].

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a block diagram of a target direction setting unit in a teaching mode according to the present embodiment. The overall configuration of the vehicle equipped with the autonomous straight-ahead device assumes that the target azimuth setting unit in the configuration of the conventional example shown in FIG. 6 is replaced by the target azimuth setting unit in FIG. The configuration and operation of the autonomous traveling mode, and the configuration and operation of the input for switching between the teaching mode and the autonomous traveling mode are the same as those of the above-described conventional example. The configuration of the embodiment will be described with reference to FIG. The target azimuth setting unit of the present embodiment detects, converts, and transmits the respective data using the vehicle speed, the moving distance, and the steering angle in addition to the conventional vehicle azimuth as data on which the target azimuth is calculated. Are provided in parallel. The configuration for detecting, converting and transmitting the vehicle direction is the same as that in FIG. The configuration for detecting, converting, and transmitting the steering angle is the same as that in FIG.

The structure for detecting, converting and transmitting the vehicle speed is mounted near the wheel 7 shown in FIGS. 6 and 8, detects the rotation angle of the wheel 7 at a predetermined resolution, and outputs the rotation angle as a pulse signal. Vehicle speed sensor 8 and vehicle speed sensor 8
A counter circuit 81 that counts the number of pulses of the pulse signal output from the CPU and converts the pulse signal into an integrated pulse signal; and a vehicle speed signal (hereinafter referred to as a vehicle speed signal V) that is periodically read out from the integrated pulse signal and can be used by a processing unit of the CPU. ), And the converted vehicle speed signal V is transmitted to the teaching management unit 41, the integrated pulse signal is transmitted to the moving distance calculation unit 10, and the vehicle speed calculation unit 9 is transmitted based on the transmitted integrated pulse signal. An increment of the moving distance (hereinafter, referred to as a distance increment ΔS) is calculated, and the calculated distance increment ΔS is used as the teaching management unit 41.
And a moving distance calculating unit 10 for transmitting the moving distance to the moving object. The distance increment ΔS is calculated by multiplying the integrated pulse signal read for each detection cycle by a distance scale factor. The configuration for detecting, converting and transmitting the steering angle is attached to the steering angle changing device 6 shown in FIGS. 6 and 8, and the steering angle sensor 1 for detecting the steering angle is used.
1 and AD for digitally converting the detection value of the steering angle sensor 11
The output of the conversion circuit 21 and the AD conversion circuit 21 is a predetermined signal (hereinafter, referred to as a steering angle signal δ) that can be used in the following processing unit.
The steering angle calculator 12 is configured to calculate the actuator drive amount and transmit it to the teaching manager 41. In FIG. 8, for convenience of explanation of input / output, the AD conversion circuit is configured as a transmission path of the vehicle azimuth and a transmission path of the steering angle. A configuration in which a time difference is provided and the AD conversion of the vehicle azimuth and the steering angle is covered by one AD conversion circuit may be adopted.

The teaching management section 41 of this embodiment is different from the processing of the teaching management section 4 of the conventional example. A method of calculating the target direction by the teaching management unit 41 will be described. The teaching management unit 41 calculates the vehicle azimuth signal (hereinafter referred to as azimuth signal さ れ る) input at regular intervals and the calculation of 値 (ψ · ΔS), which is a value obtained by integrating the distance increment ΔS, in the data detection during teaching travel ( Sampling).
Since the calculation of the integral value Σ (ψ · ΔS) is distance integration, the distance increment ΔS during the vehicle stop period is 0 (zero), and the integral value does not increase during the stop period in which the same azimuth is continuously detected. Further, in order to calculate the total traveling distance in the teaching mode (hereinafter referred to as the teaching distance St), the distance increment ΔS is periodically added during traveling, and St = Σ
It is calculated as ΔS. When the teaching mode ends, the integral value Σ (ψ · ΔS) and the teaching distance St are stored and held in the teaching management unit 41. The teaching management unit 41 performs these arithmetic processing and storage and storage separately in the forward and return teaching modes.
At the end of the teaching run, that is, the integral value Σ
At the time when the calculation of (積分 · ΔS) and the teaching distance St is completed, the integrated value Σ (ψ · ΔS) and the teaching distance St stored and held are read out, and the target azimuth (hereinafter, referred to as “target azimuth (hereinafter, referred to as
As the calculation of the target direction ψtgt), ψtgt = Σ (ψ · Δ
S) / St.

The calculation of the integral value Σ (ψ · ΔS) and the teaching distance St described above is based on the case where the vehicle travels in a state suitable for data detection from the start to the end of the travel. The target azimuth setting unit in the autonomous straight-ahead device according to the present embodiment is in a state where the steering is not stabilized and the steering angle is not converged within a certain width around the straight-ahead position as described in the problem to be solved by the invention. Also, when the vehicle speed has not reached the specified speed or more, the direction data and travel distance data during those periods are excluded from the target direction calculation data to improve the accuracy of the target direction. is there. This will be specifically described below. In the state where the accuracy is reduced as described above, the calculation of the integral value Δ (ψ · ΔS) and the teaching distance St is interrupted, and these calculated values are set to the values immediately before the interruption (hereinafter, Σ (ψ · ΔS) immediately before the interruption). Σ ′, St immediately before interruption is referred to as St ′). When the teaching management unit 41 determines from the output of each sensor that the vehicle has escaped from the above-described state in which the cause of the accuracy reduction has occurred, the calculation of the integral value Σ (ψ · ΔS) and the teaching distance St is restarted. The azimuth signal ψ and the distance increment ΔS detected after the restart are added to the integral Σ ′ and the teaching distance St ′ immediately before the interruption, and Σ (ψ · ΔS) = Σ ′ +
(Ψ · ΔS) and St = St ′ + ΔS.

Referring to FIG. 2, a processing procedure in the autonomous straight traveling apparatus according to one embodiment of the present invention will be described. Figure 2 shows the CPU
FIG. 5 is a flowchart showing a series of processes from a teaching mode to an autonomous driving mode in FIG. The initialization of the system means not only the initial setting of the CPU peripheral device at the time of starting the program, but also the initial setting and reset processing of each data stored and held in the teaching management unit 41. The switch determination means removal of the chattering phenomenon in the switch determination unit 104 and alternate determination processing of the switch state. The azimuth calculation means the azimuth signal 方位 in the azimuth calculation unit 3.
And transmission processing of the azimuth signal へ to the teaching management unit 41. The vehicle speed calculation means a vehicle speed calculation unit 9
Conversion to vehicle speed signal V and teaching management unit 4
1 and a process of transmitting an integrated pulse signal to the moving distance calculation unit 10. The moving distance calculation means a process of converting the distance increment ΔS by the moving distance calculation unit 10 and a process of transmitting the distance increment ΔS to the teaching management unit 41. The steering angle calculation means a process of calculating the steering angle signal δ in the steering angle calculation unit 12 and a process of transmitting the steering angle signal δ to the teaching management unit 41 and the actuator drive amount calculation unit 22. The mode switching is the mode switching processing unit 1 described above.
05 means transition processing of the internal mode signal. The teaching management means a process of calculating an intermediate value, which will be described later, from the azimuth data and the moving distance data, and calculating a target azimuth when the teaching mode ends. The steering control calculation means a process of generating the above-described steering control command 17 using the target direction set by the teaching management unit 41 and the vehicle direction detected during traveling. Actuator drive amount calculation means calculating a signal (actuator drive amount) for driving a steering system in order to optimize the steering angle in accordance with the steering control command 17,
3 means a process of outputting the data. The CPU periodically executes processing from switch determination to actuator drive amount calculation in the order shown in FIG.

Details of the teaching management in FIG. 2 will be described with reference to FIGS. 3, 4, and 5. FIG. 3 and FIG. 4 are flowcharts showing processing in the teaching management in FIG. FIG. 5 shows an example of a traveling pattern of the autonomous traveling vehicle. The steering angle, the vehicle direction, the vehicle speed, the calculation state of an intermediate value described later, and the moving distance in the case of the teaching travel on the outward path, which is the first stroke in FIG. It is a time chart. The teaching management shown in FIG. 3 is roughly divided into two flows. The flow on the left is a flow for executing calculation and storage of the target direction after the teaching travel is completed, and when the teaching is not performed in the standby mode. (Hereinafter referred to as flow 1). The flow branched to the right toward the right side calculates and stores and stores the integrated value Σ (ψ · ΔS) of the vehicle direction and the teaching distance St (hereinafter, collectively referred to as an intermediate value) calculated during the teaching travel. This is a flow of execution, and a flow of resetting data before starting the calculation of the intermediate value and initializing the internal mode (hereinafter, referred to as flow 2).

A series of processes for starting or interrupting the calculation of the intermediate value from the process p to the process α among the processes shown in the flow 2 will be described. Processing p to processing r in FIG. 4 is performed in such a manner that the absolute value of the steering angle is a predetermined standard value (the determination condition δst of processing r).
/ 2) (equivalent to / 2). That is, it is determined whether or not the steering is stable at a certain steering angle or less, and if it is determined that the steering is stable, the process proceeds to the next determination process. In FIG. 5, the steering angle is stabilized after the point G in the chart A, and the determination condition of the processing r is satisfied. Processing s to processing u in FIG. 4 is a predetermined standard value (corresponding to the determination condition Tst of the processing u) in which the settling time of the steering angle is predetermined.
This is a process of determining whether or not the above has elapsed. That is, the elapsed time from the last time when the steering is determined and the value falls below the standard value is measured, and when the elapsed time exceeds the steering angle stabilization time Tst and is determined to be equal to or less than the standard value, the process proceeds to the next determination process. It is a thing. In FIG. 5, the steering angle is settled after the time point H of the chart A, and the determination condition of the processing u is satisfied.

Processes v to x in FIG. 4 are processes for determining whether or not the vehicle speed is equal to or higher than a predetermined standard value (corresponding to the determination condition Vst of the process x). That is,
This is for determining whether or not the vehicle speed has reached a minimum speed suitable for calculating the intermediate value. In FIG. 5, the vehicle speed reaches a speed suitable for calculation of the intermediate value for the first time after the time point I of the chart C, and satisfies the determination condition of the process x.

If it is determined that the vehicle speed has reached the standard value or more from the processing v to the processing x in FIG. 4, the processing proceeds sequentially from the processing y to the processing α, and the integration value Σ (ψ · ΔS) as the intermediate value and the teaching The calculation of the distance St and the storage and holding of the calculation result in the teaching management unit 41 are executed. In addition, when it is determined that even one of the three determination processes described above does not satisfy the condition as before the time point H of the chart A in FIG.
In this process, the process proceeds to the process 1 via the flow 3 without calculating the intermediate value. In the process 1, the internal mode signal read out in the process a and used in the determination of the process b is read out in the next process c or process m and stored and held in the teaching management unit 41 for use as the previous internal mode signal. You. Thereafter, the process returns to the processing procedure of the CPU in FIG. That is, it is determined that the teaching management processing in FIG. 2 has been completed, and the processing following the steering control calculation is started.

The case where the calculation of the intermediate value is restarted will be described by taking, as an example, the case where the vehicle stops during the teaching traveling shown in the chart C in FIG. When the vehicle stops, the vehicle speed does not satisfy the determination condition in the process x in FIG. 4, and the calculation of the intermediate value is interrupted as shown in the chart D. The intermediate value is stored and held in the teaching management unit 41 immediately before the interruption. Even during the stop, the mode switching process 105 maintains the internal mode signal in the teaching mode. Also, when the running of the vehicle is resumed, the mode switching processing unit 10
The internal mode 5 remains in the teaching mode. Since the internal mode signal indicates the teaching mode when the vehicle is stopped, the teaching management unit selects flow 2 by the process b in FIG. In the process m, the previous internal mode signal, that is, the teaching mode in the interrupted state is read. In the process n, it is determined whether the calculation of the intermediate value is continued using the previous internal mode signal or whether it is about to be started. In this case, since the calculation is being continued, the process o is passed, and the flow moves to the process p and thereafter in FIG. Here, it is assumed that the vehicle restarts running from a stopped state and the vehicle speed increases from zero speed. Then, in the teaching management flow, since each determination is performed based on the determination conditions from the processing p to the processing x,
When the steering angle determination and the steering angle stabilization time determination are Yes, the vehicle speed signal V read out in the process v corresponds to the lowest vehicle speed determination condition Vst read out in the process w (corresponding to the determination condition Vst of the chart C in FIG. 5). At this point, the flow moves to the processing y and thereafter. Here, the teaching distance St (process z) and the integrated value Σ (ψ · ΔS) are calculated using the intermediate value before the interruption (process α), and the storage and holding in the teaching management unit 41 is resumed. Thereafter, the processing procedure of the CPU returned from the teaching management in the execution of the processing 1 shifts to the steering control calculation of FIG. 2, but since the internal mode signal is the teaching mode, no processing is performed and the loop of FIG. , And once again makes a round to return to the teaching management processing. This is continued until the user presses the teaching switch 101 to end the teaching travel.

A description will be given of a process of calculating the target direction after the end of the teaching travel. When the user presses the teaching switch 101 in the teaching mode, the teaching mode is canceled as shown in a chart J in FIG. (However, the previous internal mode signal at this time remains in the teaching mode state.) In the teaching management processing of FIG. 2, in response to the mode transition described above, the flow immediately below the standby mode side is performed by processing b in FIG. Is selected. The previous internal mode signal read in the next process c still indicates the teaching mode state. In the process d, the end of the calculation of the intermediate value is selected, and the flow branches to the flow 1 after the process e. (Here, if the previous internal mode signal is the standby mode, the system has not transitioned to the teaching mode after the start-up, that is, the intermediate value has not been calculated, or the target direction has been acquired by teaching travel. Indicates that the flow is already completed.In both of the above-mentioned two states, the flow 4 is selectively branched in the processing d, and the internal mode signal used for the current determination is stored and held in the next processing l. ) In processing e and processing f, the latest integral value Σ (ψ · ΔS) and teaching distance S
t is read. In process g, the target direction ψtgt is calculated. In the processing h, the teaching mode (forward path) or the teaching mode (return path), which is the teaching mode signal determined by the mode switching processing unit 105, is read.
In the process i, it is determined whether the calculated target direction is for the outward route or for the return route.
1 (processing j or processing k). In process l, the internal mode signal used for the current determination is read out in the next process c or process m, and is stored and held in the teaching management unit 41 for use as the previous internal mode signal.

A description will be given of a case where the data such as the intermediate value acquired during the teaching travel and the calculated target direction are reset and the teaching travel itself is abandoned on the way. When the user performs the above processing, the teaching switch 101
And the autonomous traveling switch 102 are simultaneously pressed. Thus, the states of both switches are transmitted to the mode switching processing unit 105 via the switch determination unit 104. Since the mode switching processing unit 105 collectively manages the transition state of the internal mode, a function for detecting a state in which both switches are pressed simultaneously, which is not a normal operation, is added. By executing a series of processes from the initialization of the system shown in FIG. 2, the same procedure as when the autonomous straight-ahead device is started can be realized.

[0032]

As described above, the autonomous straight-running apparatus according to the present invention has the target azimuth ψ in the teaching mode.
The calculation of tgt employs a method of integrating the detected vehicle azimuth で with the movement distance increment ΔS in the azimuth detection cycle, and dividing the integrated value by the total movement distance (teaching distance St). Therefore, even if the vehicle stops during the teaching travel, the vehicle direction data at the time of stop, which is an error factor, can be excluded from the basic data for calculating the target direction,
The calculation of the target direction can be performed with high accuracy. Further, the autonomous straight-running device according to the present invention includes a steering angle sensor for detecting a steering angle and a vehicle speed sensor for detecting a vehicle speed. The steering state in which the vehicle azimuth which is an error factor of the target azimuth calculation is detected is determined from the information obtained by these sensors, and the vehicle azimuth data in the inappropriate steering state is excluded from the basic data of the target azimuth calculation. is there. With this operation, the target azimuth can be calculated with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram of a target direction setting unit in a teaching mode according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a series of processes from a teaching mode to an autonomous driving mode in a CPU according to the embodiment of FIG. 1;

FIG. 3 is a flowchart showing processing in teaching management in FIG. 2;

FIG. 4 is a flowchart showing processing in teaching management in FIG. 2; It represents a part that could not be shown in FIG.

FIG. 5 is a traveling pattern of the autonomous traveling vehicle according to the embodiment of FIG. 1;

FIG. 6 is a block diagram showing a configuration in a teaching mode in a conventional autonomous straight-ahead device including a target direction setting unit.

FIG. 7 is a diagram showing a relationship among various elements in a conventional autonomous vehicle.

FIG. 8 is a block diagram illustrating a configuration in an autonomous traveling mode in an autonomous straight-ahead device including a target direction setting unit according to a conventional example.

FIG. 9 is a schematic diagram of a traveling pattern of a conventional example and an autonomous traveling vehicle according to the present invention.

FIG. 10 is a time chart showing an example of a state of a teaching switch and a transition state of a teaching mode signal corresponding to teaching traveling in FIG. 9;

FIG. 11 is a time chart illustrating an example of a transition state of an internal mode in a conventional example and a mode switching processing unit according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Geomagnetic sensor 2, 21 ... AD conversion circuit 3 ... Azimuth calculation part 4, 41 ... Teaching management part 5 ... Steering control calculation part 6 ... Steering angle change device 7 ... Wheels 8 ... Vehicle speed sensor 9 ... Vehicle speed calculation part 10 ... Moving distance calculation unit 11: steering angle sensor 12 ... steering angle calculation unit 15 ... steering angle 16 ... vehicle direction 17 ... steering control command 18 ... target direction 19 ... vehicle 22 ... actuator drive amount calculation unit 23 ... DA conversion circuit 24 ... Actuator control circuit 81: Counter circuit 101: Teaching switch 102: Autonomous traveling switch 103: Discrete input circuit 104: Switch determining unit 105: Mode switching processing unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Osamu Yukimoto, Inventor 1-40-2, Nisshin-cho, Omiya-shi, Saitama Prefecture Within the Research Institute for Biological Sciences (72) Inventor, Satoshi Yamamoto 1-chome, Nisshin-cho, Omiya-shi, Saitama 40 No. 2 F-term in the Biological Sciences Research Institute (Reference) 3D032 CC20 DA03 DA23 DC02 DD09 EB01 EC34 GG12 GG13 5H301 AA03 BB01 BB02 CC03 DD02 GG14 GG16 GG19

Claims (8)

[Claims] 1. An autonomous straight-running device comprising: an azimuth sensor for periodically detecting an azimuth of a vehicle; and an arithmetic unit receiving the azimuth of the vehicle and calculating a target azimuth based on the azimuth of the vehicle. Moving distance detecting means for detecting a moving distance for each detection cycle of the azimuth, the calculating means receives the moving distance, and integrates the azimuth of the vehicle with the moving distance from the teaching travel start point to the end point. Calculating the azimuth integral value, calculating the total travel distance from the teaching travel start point to the end point based on the travel distance, and setting the value obtained by dividing the azimuth integral value by the total travel distance as the target azimuth. Characteristic autonomous straight-ahead device. 2. An azimuth sensor mounted on a vehicle having a steering mechanism, for periodically detecting the azimuth of the vehicle, and a calculating means for receiving the azimuth of the vehicle and calculating a target azimuth based on the azimuth of the vehicle. An autonomous straight-ahead device, comprising: a moving distance detecting unit that detects a moving distance of the azimuth of the vehicle for each detection cycle; and a steering angle sensor that detects a steering angle according to steering by the steering mechanism. The means receives the travel distance and the steering angle, calculates an azimuth integral value by an integral operation of integrating the azimuth of the vehicle with the travel distance from the teaching travel start point to the end point, and ends from the teaching travel start point. A sum of the travel distances is calculated by adding the travel distances to a point, a value obtained by dividing the azimuth integral value by a sum of the travel distances is calculated as the target azimuth, and whether the steering angle exists in a predetermined range. Or it determines, wherein the period during which the steering angle is determined not resides in a predetermined range, the autonomous straight device, characterized in that the interruption of the integral calculation and the addition of the moving distance. 3. The arithmetic unit holds a value immediately before the interruption in the integration operation as an integration value, holds a value immediately before the interruption in the addition as an addition value, and sets the steering angle within a predetermined range. When it is determined that the distance has entered, the integration operation and the addition of the moving distance are restarted, and the moving distance after the restart is added to the added value immediately before the interruption as a new added value, and the added value immediately before the interruption is obtained. A new integral value is obtained by adding a value obtained by partially integrating the azimuth of the vehicle after the restart with the moving distance after the restart to the integral value, and the latest new integral value is used as the azimuth integral value. The autonomous straight-ahead device according to claim 2, wherein the new added value is a sum of the moving distances. 4. An azimuth sensor mounted on a vehicle having a steering mechanism, for periodically detecting the azimuth of the vehicle, and calculating means for receiving the azimuth of the vehicle and calculating a target azimuth based on the azimuth of the vehicle. An autonomous straight-ahead device, comprising: a moving distance detecting unit that detects a moving distance of the azimuth of the vehicle for each detection cycle; and a steering angle sensor that detects a steering angle according to steering by the steering mechanism. The means receives the travel distance and the steering angle, calculates an azimuth integral value by an integral operation of integrating the azimuth of the vehicle with the travel distance from the teaching travel start point to the end point, and ends from the teaching travel start point. The sum of the travel distances is calculated by adding the travel distances to a point, and a value obtained by dividing the azimuth integral value by the total sum of the travel distances is calculated as the target azimuth. And determining whether or not the steering angle is within the predetermined range. During the period when the steering angle is determined not to be within the predetermined range over the predetermined period, the interruption of the integration operation and the addition of the moving distance is interrupted. An autonomous straight-ahead device. 5. The arithmetic unit holds a value immediately before the interruption in the integration operation as an integrated value, holds a value immediately before the interruption in the addition as an added value, and sets the steering angle to the predetermined value. When the calculating means determines that the distance is within the predetermined range over a period, the integration operation and the addition of the movement distance are restarted, and the movement after the restart is added to the added value immediately before the interruption. Adding a distance to a new added value, adding a value obtained by partially integrating the azimuth of the vehicle after the restart with the moving distance after the restart to the integrated value immediately before the interruption as a new integrated value, The autonomous straight-ahead device according to claim 4, wherein the latest new integral value is the azimuth integral value, and the latest new addition value is the sum of the moving distances. 6. The moving distance detecting means detects a rotation angle of a wheel of the vehicle at a predetermined resolution and converts the rotation angle into a pulse signal, and counts the number of pulses of the pulse signal. A counter circuit for converting the integrated pulse signal, a vehicle speed calculating unit for periodically reading the integrated pulse signal and converting the signal into a vehicle speed signal, and transmitting the integrated pulse signal read by the vehicle speed calculating unit to convert the signal into the travel distance The autonomous straight-ahead device according to claim 1, further comprising a moving distance calculation unit. 7. An autonomous straight-ahead device, comprising: an azimuth sensor for periodically detecting the azimuth of a vehicle; and an arithmetic unit receiving the azimuth of the vehicle and calculating a target azimuth based on the azimuth of the vehicle. A vehicle speed sensor that detects the rotation angle of the wheel at a predetermined resolution and converts the rotation angle into a pulse signal; a counter circuit that counts the number of pulses of the pulse signal and converts the pulse number into an integrated pulse signal; A vehicle speed calculator that periodically reads out and converts the signal into a vehicle speed signal; and a movement distance calculator that receives the integrated pulse signal read by the vehicle speed calculator and converts the integrated pulse signal into the movement distance. A direction integration value is calculated by an integration operation of receiving the vehicle speed signal and the travel distance and integrating the azimuth of the vehicle with the travel distance from the teaching travel start point to the end point, and calculating the azimuth integration value. To the end point to calculate the sum of the travel distances, calculate the value obtained by dividing the azimuth integral value by the sum of the travel distances as the target azimuth, and determine whether the vehicle speed has reached a predetermined speed. Determining whether or not the vehicle speed has not reached a predetermined speed, the integration operation and the addition of the moving distance are interrupted. 8. The arithmetic means holds a value immediately before the interruption in the integration operation as an integral value, holds a value immediately before the interruption in the addition as an addition value, and sets the vehicle speed to a predetermined speed. When the calculating means determines that the time has been reached, the integration operation and the addition of the moving distance are restarted, and the moving distance after the restart is added to the added value immediately before the interruption as a new added value, A new integral value is obtained by adding a value obtained by partially integrating the azimuth of the vehicle after the resumption with the moving distance after the resumption to the integral value immediately before the interruption to obtain a new integral value. The autonomous straight-ahead device according to claim 7, wherein a value of the new addition value is a sum of the moving distances.