JPH08115127A - Travel control method for traveling object - Google Patents

Abstract

PURPOSE: To perform exact travel by detecting the amounts of deviations from a guide line at two fixed points before and behind a traveling object with the passage of time, calculating manipulated variables by calculating a deviation angle, deviation angular velocity and offset correction amount, and controlling the amount of deviation to '0' by applying velocity difference between left and right traveling motors using these manipulated variables. CONSTITUTION: The traveling motors are provided to respectively drive left and right axles, and the traveling object travels along the guide line drawn on the surface of a road. Amounts x1 and x2 of deviations from the guide line at two fixed points before and behind the traveling object are detected every moment. A deviation angle θ to the guide line, deviation angular velocity θ' and offset correction amount are calculated while using the detected values x1 and x2 on condition of x=x1 , x=x2 or x=(x1 +x2 )/2. Based on these results, a manipulated variable Δ' is calculated by an expression and the velocity of the left side or right side traveling motor is respectively controlled by using this manipulated variable Δ'. Thus, the deviation amount is controlled to x1 =x2 =0 by applying the velocity difference between the left and right traveling motors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control method for a traveling body traveling on a trackless road surface.

[0002]

A traveling crane is one of the traveling bodies traveling on a road surface having no track.

The traveling control in such traveling crane is
Conventionally, the rotational speed V ₁ of the right wheel and the rotational speed V ₂ of the left wheel of the traveling crane are detected along a guideline drawn on the traveling road surface, and ΔV = (V ₁ −V ₂ ) / 2.
Was used as the operation amount, and the running motor on the delayed side was accelerated to control the amount of deviation from the guideline.

Further, in this method, as shown in FIG.
Detecting the deviations x ₁ and x ₂ with respect to the guideline 6 at _two locations a and b in front and rear of the traveling crane,
The shift angle θ and the shift angular velocity are calculated based on this shift amount,
Further, the speed operation amount is obtained based on these, and the left and right traveling motors are controlled based on the speed operation amount to correct the deviation.

However, in such a conventional method, in the case where the traveling body is loaded with a suspender hung by wires such as a crane and travels, a right wheel and a left wheel are used. The load applied to the wheel may be unbalanced. In that case, a difference in diameter occurs between the tires of the left and right wheels, and as shown in FIG. 8, the deviation amount between the front and rear two fixed points a and b in the speed control is Although it can be corrected, the vehicle travels while maintaining the amount of deviation (offset amount) from the guideline 6. This offset amount changes depending on the diameter difference of the tire, and if it is significant, there is a concern that the traveling body itself may interfere with the container or the like in the yard.

It is an object of the present invention to eliminate a difference in diameter between right and left tires, a front and rear inclination of a road surface, and a deviation angle and an offset due to a left and right inclination of a road surface, which is called a rain gradient, in a traveling body traveling along a guideline. The object of the present invention is to provide a traveling control method in which a traveling body can always travel accurately on a guideline.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and the first method thereof is to provide a traveling motor for individually driving the left and right wheels and to follow a guideline drawn on the road surface. A traveling control method for a trackless traveling body that is traveled by means of detecting the deviations x ₁ and x ₂ from the guideline at two fixed points before and after the traveling body, and detecting the detected values x ₁ and x ₂ . Using x = x ₁ or x = x ₂ or x =
As (x ₁ + x ₂ ) / 2, the shift angle θ, the shift angular velocity θ ′ and the offset correction amount with respect to the guideline are calculated, and based on these, the manipulated variable ΔV ′ is calculated by the following equation (3).
Is calculated and the left or right traveling motors are individually speed-controlled using this manipulated variable ΔV ′ to give a difference in speed to the left and right traveling motors so that the deviation amount is x ₁ = x ₂ = 0.
It is characterized by controlling so that

[0008]

(Equation 3)

According to the first method, when the deviation amounts x ₁ and x ₂ with respect to the guideline at two fixed points in the front and rear of the running body are detected every moment, the deviation angle θ, the deviation angular velocity θ ′ and The offset correction amount is calculated, and the manipulated variable ΔV ′ is calculated from these in accordance with the above equation (2), and the traveling motors on the left side and the right side of the traveling body are individually subjected to the speed difference based on the calculated manipulated variable ΔV ′. And is controlled moment by moment so that the shift amount becomes x ₁ = x ₂ = 0,
As a result, the offset amount with respect to the guideline is corrected to 0, and the traveling body travels straight on the guideline accurately.

A second method of the present invention is a further improvement of the first method, which is provided with a traveling motor for individually driving the left and right wheels, and which follows a guideline drawn on the road surface. A travel control method for a trackless traveling body that is traveled as follows, wherein the deviation amounts x ₁ and x ₂ from the guideline at two front and rear fixed points of the traveling object are detected every moment, and the average value of the deviation amount x _m = The command speed difference ΔV of the left and right traveling motors is calculated so that (x ₁ + x ₂ ) / 2 is set to 0 and the deviation angle θ is set to the target value θ _S calculated from the road surface inclination measured in advance. It is characterized in that the left and right traveling motors are individually controlled in speed by applying the speed difference to allow straight traveling according to the guideline.

The third method is a more specific version of the second method, and is characterized in that the command speed difference ΔV is calculated by the following equation (4).

[0012]

[Equation 4]

According to the second and third methods, by introducing the target value θ _S of the deviation angle and performing the proportional and integral operations, the deviation angle which is inevitably generated when the left and right road surface inclinations exist. The responsiveness to θ can be improved.

In particular, when the traveling body is a traveling crane, the crane is required to have a target deviation angle θ when changing the traveling direction.
By rotating to _S fast, it is possible to prevent transiently exceeding the allowable range from the guideline.

Further, the average value of the deviation amount x _m = (x ₁ +
By controlling x ₂ ) / 2, it becomes possible to increase the control margin with respect to the allowable range from the guideline. Further, the average value of the deviation amount x _m = (x ₁ +
An integral term of x ₂ ) / 2 can be introduced to remove the offset from the guideline during steady running.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a schematic perspective view of a traveling crane according to an embodiment of the present invention.

In FIG. 1, the crane 1 is constructed by connecting the upper portions of the left and right leg structures 2a and 2b with a connecting member 7. Wheels 3a and 3b are provided at the lower ends of the front and rear portions of the left and right leg structures 2a and 2b, respectively. These wheels 3a and 3b are individually driven by the traveling motors provided in the wheels. The wheels 3a and 3b have tires.

Inside the left and right leg structures 2a and 2b, a suspending tool 4 is suspended via a wire 5, and a load is placed on or suspended from the suspending tool 4. Has become.

When the crane 1 travels, the following measures are taken to prevent the crane from traveling outside the guideline 6 due to actual tire diameter differences, changes in road surface conditions, and the like.

At the two points a and b on the front side and the rear side of the leg structure 2a on the right side in the traveling direction, the overhanging members 9 are respectively provided.
a and 9b are provided, and the overhang members 9a and 9b are provided with displacement detectors 8a and 8b that detect a displacement from the guide line 6 drawn on the road surface. These deviation detectors 8
The amount of deviation from the guideline 6 is detected momentarily by a and 8b, and the speed of the right wheel 3a or the left wheel 3b, that is, the right or left traveling motor is controlled based on the detected value.

FIG. 2 shows a control block diagram of the crane 1. In FIG. 2, 11 is a notch operated by an operator, 8a and 8b are the deviation detectors, 1
2 is a running track control device, 13a and 13b are left and right running speed control devices, 14a and 14b are left and right running motors, and 1
Reference numerals 5a and 15b denote rotation speed detectors that detect the rotation speeds of the left and right traveling motors 14a and 14b, and the command value V ₀ is input from the notch 11 to the traveling trajectory control device 12 at the beginning of traveling.

(First Embodiment) Next, a first embodiment of a traveling control method using the apparatus shown in FIGS. 1 and 2 will be described. When the crane 1 traveling along the guideline 6 based on the initial command value V ₀ is caused to travel with a certain inclination with respect to the guideline 6 as shown in FIG. Assuming that the amounts of deviation from the guideline 6 detected by the deviation detectors 8a and 8b provided at are x ₁ and x ₂ , the deviation angle θ,
The deviation angular velocity θ ′ is expressed as follows. θ = 1 / L (x ₁ −x ₂ ) (5) θ ′ = dθ / dt (6) where L: distance between fixed points a and b

From this, x = x ₁ or x = x ₂ , or x
= (X ₁ ÷ x ₂ ) / 2, the speed operation ΔV ′ is calculated by the following equation.

[0024]

(Equation 5)

Further, the velocity command values V ₁ and V _{2 of} the left and right traveling motors are calculated by using the ΔV 'by the following equations (8) and (9). V ₁ = V ₀ + ΔV ′ (8) V ₂ = V ₀ −ΔV ′ (9)

Alternatively, when the initial command value V ₀ is the maximum speed, V ₁ = V ₀ + ΔV '(as ΔV> 0) cannot be established, so that it is only necessary to slow down either the left or right acceleration. Good. That is, when ΔV ′> 0, V ₁ = V ₀ − | ΔV ′ | V ₂ = V ₀ (10) When ΔV ′ <, V ₁ = V ₀ V ₂ = V ₀ − | ΔV ′ | (11) Become.

The traveling control is performed according to the procedure shown in the flow chart of FIG. In other words, first the traveling crane 1
Runs based on the initial command value V ₀ (step (1)). When the traveling crane 1 is displaced from the guideline 6, the displacement detectors 8a and 8b detect displacement amounts x ₁ and x.
₂ is measured (step (2)), and these deviations x ₁ ,
Based on x ₂ , the travel trajectory control device 12 calculates the deviation angle θ, the deviation angular velocity θ ′, and the offset correction amount S (step (3)).

Based on the above calculation result, the manipulated variable Δ'is calculated (step (4)), and the manipulated variable ΔV 'is input to the traveling speed control devices 13a and 13b, so that the left and right motors 14 are driven.
a and 14b are controlled. Left and right motors 14a, 14b
Are individually controlled as described above, the deviation angle and the offset amount of the traveling crane 1 from the guide line 6 are gradually corrected, and the crane 1 travels on the guide line 6 accurately.

For example, when there is an unknown left / right tire diameter difference, x = 0, θ = 0, θ ′ = 0, and the left and right tire speeds ΔV ′ are

[0030]

(Equation 6)

Then, the vehicle runs straight ahead. The constant C may be [0]. Further, the constants a to d are calculated by simulation in advance, or adjusted by an actual machine test so as to be more stable.

(Second Embodiment) This embodiment is a modification of the first embodiment. In the first embodiment, the shift detector 8 provided on the crane 1
Assuming that the shift amounts from the guide line 6 detected by a and 8b are x ₁ and x ₂ , the shift angle θ can also be expressed by the following equation (13). θ = (x ₁ −x ₂ / L) + Cd (13) where L: between the fixed points a and b (that is, the deviation detectors 8a and 8b)
Distance) (see FIG. 1) Cd: when traveling direction (V ₁ , V ₂ ) as shown in FIG. 1 =
1.0 When traveling in the direction opposite to that in FIG.

The speed operation amount ΔV is calculated from the deviation amount x and the deviation angle θ by the following equation (14). ΔV = Ax + Bθ (14) where x: deviation amount (usually the deviation amount detection value on the front side in the traveling direction, x = x _{1 in} the case of FIG. ₁ ) A, B: constants (> 0)

ΔV is a command speed difference between the left and right traveling motors, and the actual speed commands for the left and right motors 14a and 14b are given by the following expressions (15) to (18).

(1) When ΔV > 0 V ₁ = V ₀ − | ΔV | (15) V ₂ = V ₀ (16) (2) When ΔV <0, V ₁ = V ₀ (17) V ₂ = V ₀ − | ΔV | (18) where V _{1 is} the speed command value for the right motor, V _{2 is} the speed command value for the left motor, and V _{0 is} the speed command value from notch 11.

That is, by feedback control of the shift amount x ₁ and the shift angle θ, x = 0, θ = 0, that is, x ₁ = x ₂ =
The traveling control is set to 0.

On the traveling road surface, however, there is an inclination generally called a rain gradient (η) in the lateral direction of the crane.
For example, in FIG. 1, when there is a constant rain gradient η that descends from left to right in the traveling direction, the crane is as shown in FIG. It runs with a certain running deviation. Here, θ ₀ is theoretically determined by the following equation (19). θ ₀ = (Sin · η) / Kc (19) where Kc: a constant determined by the side slip characteristics of the tire (usually 1.0 to 3.0)

That is, according to the conventional control equation (14), during steady traveling, the vehicle travels straight in a traveling state where ax ₁ + bθ ₀ = 0. (Where a, b>
Since 0, θ ₀ > 0, x ₁ <0). When the rain gradient η becomes large, the deviation amount x _{2 in} FIG. 5 exceeds the allowable range, and traveling control may become impossible.

Further, even in the steady state, the shift amount x ₂
Even if the rain gradient η does not exceed the permissible range, the following problems may occur during a transition. That is, the steady value when the crane 1 stops in the state of FIG. 5 and travels in the reverse direction is theoretically as shown in the figure for the same reason as above.

During the transition period from the state of FIG. 5 to the state of FIG. 6, the crane must always rotate clockwise, and at that time, the deviation x ₁ deviates from the guideline 6 beyond the allowable range. There is. If the amount of deviation exceeds the allowable range, there is a risk of collision with the traveling crane in the adjacent lane, so in practical use it will automatically stop when it exceeds the allowable range.If such a situation occurs frequently, work efficiency will increase. Inevitably lowers.

The second embodiment provides the following traveling control method in consideration of the rain gradient (the inclination of the crane in the left-right direction) as described above.

If the crane 1 is inclined to the left and right in the traveling direction, the crane 1 always travels in a state in which the crane 1 is inclined toward the traveling direction due to the balance of forces. Therefore, in this embodiment, the deviation surface target value θ _s corresponding to the road surface inclination is introduced, and the actual deviation surface θ is controlled so as to match the above θ _s . Specifically, the procedure is as follows.

(1) The shift amount x is set to the front and rear shift amounts x ₁ and x _2.
The average value of and is taken as x = (x ₁ + x ₂ ) / 2 (20).

(2) In order to eliminate the offset of the shift amount (x) and the shift angle (θ) as described above, the following integral value is introduced.

[0045]

(Equation 7)

(3) Substituting each of the above equations into the equation (14), the speed operation amount ΔV is calculated.

[0047]

(Equation 8)

FIG. 4 shows a flowchart for performing the above-mentioned arithmetic control in this embodiment. In FIG. 4, first, the shift amounts x ₁ and x ₂ are detected from the left and right shift detectors 8a and 8b at a constant cycle (step (3
1)).

The shift amount x and the shift angle θ are obtained, and then (2
The integral terms of the equations (1) to (22) are calculated (step (3
2)).

The speed operation amount ΔV is calculated by the equation (23) (step (33)). At this time, the deviation angle target value θ _s is obtained in advance as follows. The left and right road surface inclinations are actually measured for each traveling lane, and the deviation angle target value table for each lane is created from the average value in the lane by the equation (19). When the traveling lane of the crane is determined, the corresponding deviation angle target value θ _s is extracted from the table.

Further, the gains a, b, and
c and d are calculated in advance by simulation, or
The actual machine test is used to make adjustments to ensure stable driving.

Let ΔV be the command speed difference between the left and right traveling motors, and the respective motor speed command values V ₁ and V ₂ are expressed by equations (15)-
The calculation is performed at (18) and the result is output (step 34). By performing the above control, the crane 1 can be moved straight along the guide line 6 even if the traveling road has a left or right inclination.

[0053]

The present invention is configured as described above.
According to the invention of claim 1, it is possible to perform the control to set the displacement angle and the offset amount to 0 due to the longitudinal inclination of the traveling path and the tire diameter difference only by detecting the displacement amount at the two front and rear fixed points of the traveling body, The traveling body can accurately travel on the guideline.

Further, according to the inventions of claims 2 and 3, even when the road surface has a left and right slope called a rain gradient,
By introducing the target value of the deviation angle and performing the proportional and integral operations, the deviation angle and the offset amount due to the left and right tilts are set to 0
The control can be performed, and the traveling body can accurately travel on the guideline.

In short, according to the present invention, whether there is an inclination in the front or rear or the left or right due to the difference in tire diameter, the inclination of the traveling path, etc., these can be corrected promptly and the traveling body can be moved on the guideline. Can be run accurately.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a crane to which a traveling control method according to the present invention is applied.

FIG. 2 is a travel control block diagram of the crane.

FIG. 3 is a flowchart according to the first embodiment of the present invention.

FIG. 4 is a flowchart according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram regarding a deviation angle of a traveling body and an offset amount.

FIG. 6 is an explanatory diagram regarding a deviation angle of a traveling body and an offset amount.

FIG. 7 is an explanatory diagram regarding a deviation angle of a traveling body and an offset amount (both deviation angle and offset exist).

FIG. 8 is an explanatory diagram regarding a shift angle and an offset amount of the traveling body (after the shift angle is corrected).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Crane, 3a, 3b ... Wheel, 8a, 8b ... Deviation detector, 11 ... Notch, 12 ... Running track control device, 13
a, 13b ... Travel speed control device, 14a, 14b ... Travel motor, 15a, 15b ... Rotation speed detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Gou Murata 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (72) Inventor Masaki Nishioka 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd.

Claims (3)

[Claims] 1. A travel control method for a trackless traveling body, comprising a traveling motor for individually driving left and right wheels, and traveling along a guide line drawn on a road surface. The deviation amounts x ₁ and x ₂ from the guideline at the fixed point are detected moment by moment, and x = x ₁ or x = x ₂ or x = (x ₁ + x ₂ ) / 2 is set by using the detected values x ₁ and x _2. , The deviation angle θ with respect to the guideline, the deviation angular velocity θ ′, and the offset correction amount are calculated, and the manipulated variable ΔV ′ is calculated based on these, and the manipulated variable ΔV ′ is used on the left side or the right side. _2. The traveling control method for a traveling body, characterized in that the traveling motors are individually controlled in speed so that the traveling motors on the left and right are made to have a speed difference so that the deviation amount becomes x ₁ = x ₂ = 0. [Equation 1] 2. A traveling control method for a trackless traveling body which comprises traveling motors for individually driving left and right wheels, and which travels along a guide line drawn on a road surface. The deviation amounts x ₁ and x ₂ from the guideline at a fixed point are detected every moment, and the average value of the deviation amounts x _m =
The command speed difference ΔV of the left and right traveling motors is calculated so that (x ₁ + x ₂ ) / 2 is set to 0 and the deviation angle θ is set to the target value θ _S calculated from the road surface inclination measured in advance. A traveling control method for a traveling body, characterized in that the traveling motors on the right and left sides are speed-controlled individually with the speed difference, so that the traveling vehicle travels straight along the guideline. 3. The traveling control method for a traveling body according to claim 2, wherein the commanded speed difference ΔV is calculated by the following equation (2). [Equation 2]