JPS62221707A - Gyro-guide type unmanned carrier - Google Patents

Abstract

PURPOSE:To minimize the arithmetic error for the position of an unmanned carrier despite a large steering angle and to improve the stopping accuracy, by calculating the real shift amount between the center position of the carrier and the rotational center of a wheel of the carrier based on the information on the rotational frequency of an optional one or plural ones of wheels of the carrier as well as the wheel steering angles. CONSTITUTION:A rotary sensor 3 counts the distance pulses of the wheels diagonal with each other to obtain a distance traveled for a unit time. Then a steering angle rotary sensor 41 obtains an angle between a wheel and the carrier body. A traveled distance correcting part 42 calculates the average traveled distance per unit time of each of both sensors 3 and 41 to define a distance traveled per unit time. This obtained distance is set at DELTAl approximately equal to the shifted distance at the center part of the carrier. As a result, no error is produced with calculation of the carrier position despite a large steering angle and therefore the stopping accuracy is improved for the carrier.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention uses a gyro to detect the azimuth of the vehicle and calculates the position of the vehicle from this and the rotation speed of the wheels. The present invention relates to a gyro-guided automatic guided vehicle that automatically travels along a predetermined route.

(Prior technology) Trackless vehicles used for transporting goods within factories have a guide wire laid on the road surface along the travel route, and an alternating current applied to the guide wire causes a coil on the top of the vehicle to receive an electric current of 11 induction wires. There is an electromagnetic induction method that generates an output and guides the vehicle, and an optical reflective tape guidance method that uses optical reflective tape on the road surface and detects this from the vehicle while driving. There is a drawback in that when changing the running route due to a change in the process route, it is necessary to rearrange the above-mentioned guide lines and ground-side guide lines such as optical reflective tape. Therefore, in order to easily cope with the above-mentioned changes, in recent years, gyro-guided guided vehicles that can easily change travel routes have come into wide use.

FIG. 4 shows the configuration of this gyro-guided transport vehicle. Fourth
In the figure, 1 is a gyro unit, which uses a mechanical gyro or a gas rate gyro to detect the horizontal rotation of the trackless vehicle and determine the vehicle's deflection angle (attitude angle). It detects and outputs θ. Reference numeral 2 is a wheel of the trackless vehicle, and reference numeral 3 is a rotation sensor that outputs a distance pulse at every predetermined rotation angle in conjunction with the wheel 2. Reference numeral 4 denotes a trackless vehicle existence position calculation circuit (hereinafter simply referred to as calculation circuit), which calculates the deviation angle (attitude angle) from the above-mentioned position 11.
From θ and the distance Δ1 traveled per unit time determined by the distance pulse from the rotation sensor 3, the X-axis movement distance within the unit time ΔX−ΔJ! , CO3θ.

Y-axis movement distance ΔY=Δ, 1. By calculating sin θ and adding and subtracting these ΔX and ΔY from the starting point, the current position X, Y and displacement angle θ of the trackless vehicle can be determined.

Reference numeral 5 denotes a running control circuit, which controls the trackless vehicle every unit time based on the current position It gives speed commands and steering commands to both the upper and lower sides of the vehicle.

With such a structure ij3, when the trackless vehicle is traveling straight, the output of the gyro unit 1, that is, the angle, does not change, but if it swings even slightly to the left or right, an angular velocity is generated and the angle changes. This angle signal from the gyro unit 1 is input to the calculation circuit 4 as a deviation angle. Then, in the arithmetic circuit 4, the X-axis movement distance △X within unit time, Y within unit time
Calculate the axis movement distance △Y, add this distance ΔX and ΔY,
The trackless vehicle's current position In comparison, the trackless vehicle travels by controlling the steering and speed of the travel motor so that it stays on the road.

In this way, it is normally controlled by data from the gyro unit 1, so there is no need to install any sensing object such as a continuous electromagnetic induction wire or optical reflective tape for guidance.
The vehicle will be an automated guided vehicle that can handle even complex routes.

(Problem to be solved by the invention) By the way, when this automatic guided vehicle travels on a curved section as shown in Fig. 5, the steering angle of each wheel 31, 32, 33° 34 is in the perpendicular direction as shown in the figure. with a large angle from At this time, the pulses input from the rotation sensor in response to the rotation of the wheel 31 are pulses corresponding to the distance traveled in the direction of the arrow 36. This value is calculated using the above formula ΔX−Δjjcosθ, ΔY−Δ/si
When calculated using nθ, the pulse for the travel valve (corresponding to arrow 37 in the diagram) for turning the vehicle body is included in the pulse for traveling in the direction the vehicle body is facing (corresponding to arrow 38 in the diagram). I end up. From another point of view, the wheel 310 rotation pulse is the amount by which the vehicle body portion of the wheel 31 moves, and this distance is greater than the amount of movement of the vehicle body center position used for travel control. As a result, this is good when the steering angle of the wheels is small, such as when making a large curve, but when the steering angle of the wheels becomes large, the above-mentioned error becomes large, and there is a problem in that it affects stopping accuracy.

Therefore, this invention is a gyro-guided trackless guided vehicle that can reduce the calculation error of the vehicle position even when the steering angle becomes large when traveling on a curved section with a small radius, and can improve stopping accuracy. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention includes a gyro attached to the vehicle body to detect the running azimuth of the vehicle, and a gyro for counting the number of rotations of the wheels. A rotation sensor is provided to obtain the movement amount information of the vehicle from the measured value of this rotation sensor, and the current vehicle position is determined by the existing position calculation circuit based on this movement amount information and the above-mentioned traveling azimuth information. In order to make the vehicle travel along the determined course, a gyro-guided travel control device that controls each motor for travel and steering, which controls the steering angle of the wheels, based on the current vehicle position information obtained. In an automated guided vehicle, in order to determine the steering angle of each wheel and the amount of vehicle body movement from the actual rotation center when traveling on a curved road, information on the rotation speed of one or more arbitrary wheels and the steering angle of that wheel is obtained, and these The present invention is constructed by providing a correction means for obtaining the rotation radius from the rotation center of the vehicle to the wheels from the information, calculating the actual movement amount of the vehicle center position with respect to the rotation center, and using it as the movement amount information of the vehicle.

(Function) In such a configuration, the rotation speed of one or more arbitrary wheels and the steering angle of the wheels are detected, and based on these, the correction means adjusts the rotational distance between the center of rotation of the vehicle and the wheels. The radius is determined, and the actual amount of movement of the vehicle center position relative to the rotation center is calculated to obtain information on the amount of movement of the vehicle. Then, the obtained movement amount information is given to the existence position calculation circuit. Thereby, the existing position calculation circuit calculates the current vehicle position based on this movement amount information and the traveling azimuth information. In order to make the vehicle travel along a preset course, the travel control device operates each motor for travel and steering, which controls the steering angle of the wheels, based on the current vehicle position information obtained by the existing position calculation circuit. Control. As a result, when driving on curved roads, the steering angle of each wheel and the amount of vehicle body movement from the actual center of rotation can always be accurately determined, maintaining positional accuracy on sharp curves, and dramatically improving stopping position accuracy. Be able to do things.

(Example) Examples of the present invention will be described below. FIG. 1 is a block diagram showing the configuration of a gyro-guided automatic guided vehicle according to an embodiment of the present invention. 4
This is different from the case shown in the figure.

The travel distance correction unit 42 uses the rotation sensor 3 to calculate the distances ΔJ131 and ΔJ traveled in a unit time by multiplying the distance pulses of the diagonal wheels in FIG.
l:! Find 2.

Furthermore, angles α31 and α33 of the wheels relative to the vehicle body are determined by the steering angle rotation sensor 41.

Using this value, the existence position calculation circuit 4 calculates the moving distance per unit time ΔX=ΔJ4 cosθ.

ΔY=ΔJ! , 81. to find sin θ. That is,
It is necessary to determine the distance pulse in the forward direction of the vehicle (corresponding to arrow 38 in FIG. 5). At this time, the distance pulse in the lateral direction of the vehicle body (corresponding to arrow 37 in FIG. 5) is
and the vehicle 33 are in opposite directions, so they cancel each other out and are irrelevant to the calculations of ΔX and ΔY.

Here, in order to find the above Δ1, the above Δ131°△13
3. α31. The mileage correction unit 42 calculates α33 as shown below, and corrects the distance pulses of the diagonal wheels 31 and 33 by taking into account the angles the wheels make with the vehicle body. Then, the average value of these values is taken to determine the Δ1 color which is the average value of the inner and outer rings, and this is given to the existence position calculation circuit 4. Then, in the existence position calculation circuit, this average value Δ1 is used instead of the conventional one to calculate the X-axis movement distance per unit time.

The configuration is such that the Y-axis movement distance is determined and the current position of the automatic guided vehicle is output to the travel control circuit 5.

In this way, the mileage correction section 42 is provided to calculate the mileage per unit time of each of the diagonal wheels in an angularly corrected form, and then average the distances traveled per unit time for both of these calculated wheels. Since the distance traveled per unit time can be set to △1, which is approximately equal to the distance traveled by the center of the car, there is no error in calculating the position when the steering angle is large, and the stopping accuracy can be improved. You will be able to improve it.

Furthermore, the steering angle rotation sensor 41 can be a steering angle sensor used in the travel control circuit 5. In this example, rotation pulses are obtained from two wheels in four-wheel steering, but the same applies to the case where rotation pulses are obtained from one or four wheels.

FIG. 2 is a block diagram showing a modification of the present invention. The difference from the case shown in FIG. 1 is that the azimuth angle from the gyro section 1 is inputted to the travel distance correction section 42 instead of the rotation sensor 41 for steering angle.

When calculating Δ1 per unit time, the mileage correction unit 42 calculates how many times the azimuth angle of the vehicle body changes per unit time, instead of detecting the steering angle α, and uses this result to calculate the Δ1. demand.

The operation of this arithmetic unit will be explained with reference to FIG.

If the distance between the front and rear wheels of the car is W, 52.53 is the distance pulse, the azimuth that changes per unit time is Δθ, 54°55 is the forward distance component, and 56.57 is the lateral distance component, then the vehicle per unit time is When the azimuth angle is displaced by Δθ, the wheel 31.
Since 56.57, which is the moving distance of wheel 33 in the inner and outer center directions, is used for this displacement of 80, the distance traveled per unit time of wheel 31.33 is now 52. .53 is ΔJ131°8133. Therefore, by calculating this equation (2), it is possible to perform a Δ1 correction that is almost equivalent to the case of the J configuration shown in FIG. A gyro-guided automated guided vehicle with similar effects can be obtained.

[Effects of the Invention] As described in detail above, according to the present invention, the gyro has excellent features such as being able to always obtain an accurate current position even when driving on a sharp curve, and therefore having an accurate stopping position. A guided automatic guided vehicle can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a modified example, FIG. 3 is a diagram for explaining the principle of FIG. 2, and FIGS. FIG. 5 is a diagram for explaining a conventional example. 1... Rate gyro section, 2, 31.32, 33°3
4...Wheel, 3...Rotation sensor, 4...Existence position calculation circuit, 5...Traveling control circuit, 41...Rotation sensor for steering angle, 42...Distance correction unit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A gyro is attached to the vehicle body to detect the running azimuth of the vehicle, and a rotation sensor is installed to count the number of rotations of the wheels, and information on the amount of movement of the vehicle is obtained from the measurement value of this rotation sensor.
The current position of the vehicle is determined by the vehicle location calculation circuit based on this movement amount information and the above-mentioned travel azimuth information, and the vehicle is driven based on the determined current vehicle position information in order to run the vehicle according to a preset course. In a gyro-guided automated guided vehicle, which is composed of a steering wheel and a travel control device that controls each steering motor that controls the steering angle of the wheels, the steering angle of each wheel and the vehicle body from the actual center of rotation are determined when traveling on a curved road. In order to calculate the amount of movement, information on the rotation speed of one or more arbitrary wheels and the steering angle of that wheel is obtained, and from this information, the rotation center of the vehicle and the rotation radius from the wheel are determined, and the rotation of the vehicle center position is calculated. A gyro-guided automatic guided vehicle, characterized in that a correction means is provided for calculating an actual amount of movement with respect to the center and using it as movement amount information of the vehicle.