JPH03135609A - Precise stop method for omnidirectional mobile vehicle - Google Patents

Abstract

PURPOSE:To precisely stop an omnidirectional mobile vehicle at the stations, etc., by starting newly an auxiliary program to calculate an error between a target stop position and an actual stop position and to correct the error. CONSTITUTION:The distance measuring devices X1 - X8 are provided at the front and back parts and at both sides of a body 1A of an ominidirectional mobile vehicle 1. When it is regarded that the vehicle 1 reached its target stop position, an error between the target stop position and an actual stop position is calculated via the devices X1 - X8. At the same time, a 2nd auxiliary program is newly started for correction of the error. Thus it is possible to precisely and quickly stop the vehicle 1 at the stations, etc., even if an accurate distance actually traveled is not obtained owing to a mechanical error and a manufacturing error caused by the wear of wheels, etc., or the inferior resolution of each detector.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is an omnidirectional moving vehicle that performs automatic steering without a guide, and which corrects deviations from a predetermined traveling route to accurately move to a station or the like. This invention relates to a precision stopping method when stopping the machine.

(Prior art) An omnidirectional vehicle stores a planned travel route in a central processing unit installed in the vehicle body, measures the actual travel distance based on the number of rotations of its wheels, etc., and calculates the actual travel distance based on a program stored inside the vehicle body. Then, control is performed to guide the vehicle along the planned travel route.

For example, when an omnidirectional vehicle is driven straight ahead.

The distance from the travel start position to the target stop position is stored in a central processing unit installed in the vehicle body, and the omnidirectional vehicle will stop when the actual travel distance calculated from the number of rotations of the wheels, etc. falls short of the distance. is under program control.

(Problem to be Solved by the Invention) With such a configuration, it is not possible to obtain an accurate actual travel distance due to mechanical errors due to wheel wear, etc., or manufacturing errors, and it is difficult to precisely stop the vehicle at a station, etc. The problem was that it was not possible to do so.

(Means for Solving the Problem) The present invention is an omnidirectional vehicle that travels on a travel route predetermined by a central processing unit provided inside the vehicle body based on a first main program. A rotation speed detector that detects the rotation speed of the wheels of a directional vehicle.

A steering angle detector is installed to detect the steering angle of the steering wheels.

In an omnidirectional vehicle that travels on the traveling path by correcting deviation from the traveling path.

Distance measuring devices are installed at the front, rear, and both sides of the omnidirectional vehicle.

When the omnidirectional vehicle is deemed to have reached the target stop position, calculate the deviation between the target stop position and the actual stop position,
The present invention is based on a configuration including a second auxiliary program that is newly started to correct the deviation, and is intended to precisely stop an omnidirectional vehicle at a station or the like.

(Example and operation) The operation and one embodiment of the present invention will be explained below based on the drawings.

FIG. 1 illustrates a schematic configuration of an omnidirectional vehicle.

1 is an omnidirectional vehicle that transports the workpiece, IA is the body of the omnidirectional vehicle, DPI, DF2. DF3 and DF4 are steerable wheels, and steering electric motors 4, . . . are respectively provided.

The steered wheel DPI, DF2. DF3. DPI of DF4
and DF4 also serves as the driving wheel, and the driving electric motor 5.5
is installed.

Also, each wheel has a rotation speed detector 2 to detect the rotation speed.
and a steering angle detector 3 for detecting the steering angle.

Xl-X8 indicates distance measuring devices disposed two each on the front, rear, and both sides of the vehicle body IA. In this embodiment, a well-known optical distance measuring device is used, but the present invention is not limited to this. Not 1
For example, a distance measuring device such as an orange sound wave can also be used. or,
As described below, the front and sides, or the rear and sides, total 3
If one range finder can perform measurements, the other five range finders become unnecessary, so it is possible to change the mounting position of the range finder in various ways depending on the usage environment of the omnidirectional vehicle.

6 is a control device, which includes a central processing device (not shown).
and the rotation speed detector 2° and the steering angle detector 3.
．． and the data from the distance measuring devices X1 to X8 as input signals, and based on this data, a first main program stored in advance in an internal memory (not shown), and a second program to be described later.
Execute the auxiliary program of 5. Controls the steering electric motor 4.

Next, the operation of the present invention will be explained with reference to the flowchart of FIG. 5.

First, it is determined whether the omnidirectional vehicle l has received a travel command (5TEPI), and if there is a travel command (STEPI
Y) Execute the first main program (STEP 2),
The vehicle travels on a predetermined travel route (STEP 3).

Next, the omnidirectional vehicle 1 moves to a predetermined target stop position M1.
5TEP4).

If the first main program has finished (Y in STEP 4)
), execute the second auxiliary program (STEP 5),
Correct the deviation between the target stop position and the actual stop position (S
TEP6).

I will clarify.

FIG. 2 is a diagram for explaining how to use the distance measuring devices X1 to X8, and FIG. 3 is a plan view macroscopically illustrating the case where the target stopping position M1 is one corner of the wall surfaces 7 and 8 orthogonal to each other.
FIG. 4 is a flowchart showing the processing procedure of the second auxiliary program.
Let the origin of the coordinate axis representing A be the actual stopping position Ql,
The vertical axis of the coordinate system is the X axis, the horizontal axis is the Y axis, and the target stopping position, which is the position where the motor should stop, is Ml.

First, the actual stopping position Q with a deviation from the target stopping position
1, the distance measuring device X2°X3. Distances DI, D2. D3 respectively (5TEP51), and from this distance measurement data, determine the actual stop position Q1.

The deviation from the target stopping position Ml, which is stored in advance in the control device, is calculated using a well-known triangulation method (STE
P52). In addition, the final value is distance IDI.

) D.2. D3 is TI, T2. It became T3. H So, precision stop is completed.

In addition, in Fig. 3, in the above X-Y coordinates, the target stopping position Ml is (x, y) from the actual stopping position Q1, resulting in an angular deviation θ, and hereinafter, this deviation will be expressed as (x, y, θ). That's it. Also, in this state, the turning center point for correcting the vehicle body position is C, the distance between Ql and Ml is m, the midpoint of Ql-Ml is E, the distance of QiC is n, and the angle created by Ql and C-E is Za, the angle made by the X axis and the line segment Q1・Ml is zb
shall be.

Next, a distance m connecting the target stop position M1 and the actual stop position Q1 with a straight line is determined.

(STEP 53) m = J171 7 Furthermore, find the angle la created by Ql・C−E (STE
P54).

la=θ/2 Find zb (STEPs 55-59).

here When m=o b=.

When other than m=o and when y≧0, b=co s-'(x/m)y<
0, b=-cos-' (x/m).

Next, virtual steering wheels representing the steering and running of each wheel are set at arbitrary positions on the vehicle body. This virtual steering wheel is an arm 9 having a length l from a representative point of the vehicle body, and a steering wheel 10 rotatably arranged (virtually) at the tip of the arm 9. Therefore, the arm 9 (imaginary) can be rotated 360 degrees around the representative point of the vehicle body, and the steering wheel 10 (imaginary) itself can also be steered 360 degrees independently of the arm 9. Therefore, the turning center of the vehicle body can be located at any position. The arm 9 is always positioned perpendicular to the straight line n connecting the turning center point C for turning the vehicle body and the vehicle body representative point Q1, and the steering wheel 10 is positioned perpendicularly to the straight line nA connecting the turning center point C and one end 9A of the arm 9. Once the virtual steering angle α and (, z) are determined, each wheel is steered based on this.

You can decide to run.

As a process, a virtual advancing angle β is determined.

Here, β is positive when rotating 2 counterclockwise with the X axis as a reference.

(STEP 60) β=-(b+a) Find the distance of line segment n.

(STEP61~63) When θ=0 n=0 When θ≠O n=m/2sin2θ Next, a virtual steering angle α is determined (STEPs 64 to 68).

When m=o, and When θ=0 α=0 When θ〈0　 α=π/2 When θ〉0 α=-π/2 When other than the above conditions (n≠0) α-mu an-’ (1/n) Find the moving distance γ of the virtual steering wheel.

(STEP 69) r=lθXf/sinα Here, calculate the steering angle of each wheel using the virtual traveling angle β and virtual steering angle α obtained by the above calculation, and output this to the steering electric motor 4 of each wheel. 5TEP70-71), each steering electric motor 4 performs steering (STEP72).

Here, check whether the steering angle of each wheel is approximate to the calculated value obtained in 5TEP70 (5TEP73), if it is an approximate value (y in STEP73) - output a constant driving force (5TEP74), if not , 5 returns the procedure to the processing of TEP51.

5TEP75), and if γ = very small amount tolerance (
(Y in STEP 75), the output of the steering angle and driving force is stopped (STEP 76). If T is not a very small amount permissible value (N in STEP 75), the procedure returns to the process in 5TEP 51.

In addition, in the above embodiment, the target stopping position was near the perpendicular wall, but in the case where the target stopping position is set, for example, in the center of the traveling area of the omnidirectional vehicle, as shown in FIG. As illustrated in FIG. 7, a wall member W exclusively for precision stopping may be provided along the outer edge of the target stopping position. Namely.

This wall member W may have a size that can be measured by the distance measuring device of the omnidirectional moving vehicle, and may be modified in two ways, such as those that intersect at right angles, or those that intersect at any predetermined angle. can do.

(Effects of the Invention) The present invention calculates the deviation between the target stopping position and the actual stopping position using a distance measuring device when it is assumed that the omnidirectional vehicle has reached the target stopping position, and calculates the deviation between the target stopping position and the actual stopping position. Since the configuration includes a second auxiliary program that is newly started for correction, mechanical errors due to wheel wear, manufacturing errors, etc.
Alternatively, even if it is not possible to obtain an accurate actual travel distance due to the decomposition ability of each detector, etc., it is possible to accurately and quickly stop the vehicle at a station or the like.

This effect is particularly significant in environments such as unmanned warehouses or clean rooms that require precision in stopping positions.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the schematic configuration of the present invention, Fig. 2 is a plan view illustrating the use of the distance measuring device, and Fig. 3 is a macroscopic view showing the case where the target stopping position is one corner of a mutually orthogonal wall surface. FIG. 4 is a flowchart showing the processing procedure of the second auxiliary program, and FIG. 5 is a flowchart for explaining the main routine for driving the omnidirectional vehicle of the present invention. FIGS. 6 and 7 are plan views showing other embodiments. 1----Omnidirectional vehicle 4- Steering electric motor IA-
Vehicle body 5- Travel electric motor 2- Rotation speed detector 6- Control device No. 2 y Fig. 5

Claims (3)

[Claims] (1) An omnidirectional vehicle that travels on a travel path predetermined by a central processing unit installed inside the vehicle body based on a first main program, and the rotation speed of the wheels of the omnidirectional vehicle is detected. An omnidirectional vehicle that is provided with a rotation speed detector that detects a steering angle of a steered wheel, and a steering angle detector that detects a steering angle of a steered wheel, and that travels on the traveling path while correcting a deviation from the traveling path. Distance measuring devices are installed in the front, rear, and both sides of the vehicle body, and when the omnidirectional moving vehicle is deemed to have reached the target stopping position, the deviation between the target stopping position and the actual stopping position is calculated,
A method for precisely stopping an omnidirectional vehicle, comprising: a second auxiliary program that is newly started to correct the deviation. (2) In the above claim (1), an arbitrary wall member having two mutually orthogonal surfaces serving as a reference is provided along the outer edge of the target stopping position of the omnidirectional moving vehicle on the traveling path. Precise stopping method for omnidirectional moving vehicles. (3) A precision stopping method for an omnidirectional vehicle according to claim (2), characterized in that arbitrary wall members having two mutually orthogonal surfaces intersect at an arbitrary predetermined angle. .