JPH0635316B2 - Automated guided vehicle guidance device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for guiding an unmanned transport vehicle having a load on its front part by means of lateral guide surfaces.

2. Description of the Related Art In recent years, unmanned forklifts and unmanned carriers have been developed for the purpose of labor saving in on-site transportation vehicles such as forklift trucks (hereinafter referred to as forklifts).
In order to guide such an unmanned transport vehicle, in the present application, a guide member (including a side wall of a container, etc.) installed on the ground, and a vehicle provided on the side of the vehicle are provided. A guide device including a guide surface detecting means for detecting the guide surface of the guide member and causing the vehicle to travel along the guide surface is proposed.

Problems to be Solved by the Invention According to such a guide surface follow-up type guiding device, a high guiding accuracy such as straightness can be obtained, but a portion where the distance to the vehicle suddenly changes for some reason in the middle of the guide surface. (Steps, etc.) may occur. For example, in order to load a load from the platform into the container sequentially, a side wall of the container is attached to a fixed guide wall installed on the platform, and an unmanned forklift or the like is installed along the guide surface formed by the guide wall and the side wall of the container. When attempting to run the unmanned vehicle, there may be a case where a step is generated between the container side wall and the guide wall due to the shift of the stop position of the container. In this way, if there is a portion where the distance to the vehicle changes abruptly in the middle of the guide surface, it is difficult to properly guide the vehicle because the detection capability of the guide surface detection means and the following ability of the vehicle are limited. If
The trailer must be cut back many times to accurately position the container until the side wall of the container is aligned with the guide wall, which requires a considerable amount of time.

Therefore, it is conceivable to gradually eliminate a staggered portion such as a step formed in the middle of the guide surface by a relatively long inclined portion such as a rotating wall. This would allow the vehicle to follow the guide surface and eliminate all the problems. However, since the distance between the load on the front part of the vehicle and the guide surface is usually short, and the guide surface detecting means of the vehicle is located behind the load, the guide surface detecting means detects the inclined portion of the guide surface. Another problem arises in that the cargo comes into contact with that part, and unless this problem is resolved, the problem as a whole cannot be resolved.

Means for Solving the Problems The present invention has been made to solve the problem of the device for guiding the automatic guided vehicle having the load on the front portion by the side guide surfaces as described above. The tilting device according to the present invention includes the following prefectures.

(a) A movable guide member that is rotatably connected to an end of a fixed guide member provided on the ground around a vertical line and forms the guide surface together with the fixed guide member. (b) Provided on the unmanned guided vehicle. The guide surface detecting means for detecting the guide surfaces of the two guide members (c) The angle detecting means for detecting the rotation angle of the movable guide member with respect to the fixed guide member (d) The angle detected by the angle detecting means. Accordingly, the position of the load in the left-right direction is changed, and the load position control means for avoiding contact between the load and the guide surface of the movable guide member. In the case of a forklift equipped with a side shift attachment for side-shifting the fork and the vehicle in the left-right direction of the vehicle, the load position control means is set to the site shift. Attachment, aspects that make up the side shift of its attachment as including a side shifting amount detecting means for determining in accordance with the detected value of the angle detection means is preferred.

EFFECTS OF THE INVENTION In the guiding device configured as described above, the movable guide member that is rotatable around the vertical line eliminates discontinuities such as the steps and disagreements that cannot keep the vehicle following ability as they are. Thus, for example, by connecting the free end of the movable guide member to the side wall of the container, it is possible to absorb the shift in the post-installed position of the container.

Moreover, the position of the load in the left-right direction is changed according to the rotation angle of the movable guide member with respect to the fixed guide member so as to avoid contact between the load and the guide surface of the movable guide member. Despite the inclination of the guide member, the load of the vehicle does not contact the guide surface of the movable guide member, and it is possible to insulate the vehicle along the angled guide surface while protecting the load. It will be.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

1 and 2 show an example in which the present invention is applied to a guide device for a counterbalance type forklift. In the figure, reference numeral 2 is a vehicle body, in which the front wheels are drive theory 4 and the rear wheels are steering shafts 6. A balance weight 8 is provided on the vehicle body 2 thereafter, and a head guard 10 is provided above the balance weight 8. As well known, a cargo handling device including a fork 12, an outer mass 14, and an inner mast 16 is provided in front of the vehicle body 2. The inner mast 16 is guided in the vertical direction by the outer mast 14 via rollers, and the inner mast 16 further guides the lift bracket 18. A finger bar 20 is attached to the lift bracket 18 via a side shift attachment 19, and a pair of forks 12 is attached to the finger bar 20. Then, when the inner mast 16 is lifted by the operation of the lift cylinder 22, the lift bracket 18, the finger bar 20, and the fork 12 are integrally lifted by a chain (not shown).
The lower end portion of the outer mast 14 is rotatably attached to the vehicle body 2 around one axis, and the tilt cylinder 24 operates to tilt the cargo handling device starting the outer mast 14 forward or backward. Further, the operation of the side shift cylinder 26 causes the finger bar 20 and the fork 12 to be side-shifted with respect to the lift bracket 18 in the left-right direction of the vehicle body 2.

The forklift 28 can be manned by maneuvering a driver's vehicle, but can also be manned by guidance using a guide wall 30 as shown in FIG.

Lateral displacement sensors 32 and 34, which come into contact with the guide wall 30 and detect the distance and running posture of the vehicle body 2 with respect to the guide wall 30, are attached to the side portions of the vehicle body 2 as guide surface detection means. The lateral displacement sensor 32 includes a box 36 fixed to the vehicle body 2 as shown in FIG. 3, and an entrance / exit member 38 is provided in the box 36. The entrance / exit member 38 is fixed to the elongated main body 40, the crossbars 42 and 43 fixed at right angles to one end and the upper surface of the intermediate portion of the main body 40, and the lower surface of the intermediate portion of the main body 40. A slider 44, and a slider 44
Is supported by a guide rail 45 fixed to the box 32 so as to be movable in a direction perpendicular to a wall surface 46 of the guide wall 30 (hereinafter referred to as a guide wall surface 46 because this wall surface 46 functions as a guide surface). This access member 3
8 is constantly urged toward the guide wall surface 46 by two springs 47, and the amount of coming in and out of the box 36 is detected by a linear potentiometer 48. A contact plate 52 having a U-shaped cross-section is attached to the tip of the main body 40 of the entrance / exit member 38 so as to be rotatable about the axis of the vertical shaft 50 in the middle. The contact plate 52 is held in a neutral position, which is normally perpendicular to the body 40, by two symmetrically arranged springs 54. Both ends of the contact plate 52 are curved in a direction away from the guide wall surface 46, and as shown in FIG. 4, the rollers 56 are located at positions slightly exposed to the outside from the respective curved surfaces through the notches. Is rotatably mounted, and when there are obstacles such as protrusions on the guide wall surface 46, the contact plate 52 is rotated around the axis of the shaft 50 to help get over it. If a crawler belt (circling belt) made of a flexible material such as rubber is wound around the rollers 56 and the crawler belt is brought into contact with the guide wall surface 46 to move around, the friction with the guide wall surface 46 is prevented. Avoidance is improved and followability and durability are improved.

The other lateral displacement sensor 34 has a similar configuration, and the output signals of the linear potentiometers 48 of the lateral displacement sensors 32 and 34 of both of them provide the vehicle body 2 and the guide wall surface 46.
The distance between the load W supported by the pair of forks 12 and the guide wall surface 46 is detected. In addition, due to the output difference of both linear potentiometers 48, the vehicle body 2
The inclination (running posture) around the vertical line with respect to the guide wall surface 46 is detected.

The forklift 28 as described above is shown in FIGS.
As shown in the figure, it is used for sequentially loading the load W sent by the chain conveyor 62 installed on the platform 60 into the container 66 that is retrofitted to the platform 60 via the transfer plate 64. is there. The chain conveyor 62 is embedded in the platform 60 so that the chain slightly projects from the floor surface of the platform 60, and the forklift 28 can travel across the chain conveyor 62.

The platform 60 is provided with the guide wall 30. The guide wall 30 is formed by connecting a fixed guide wall 68 that functions as a fixed guide member and a movable guide wall 70 that functions as a movable guide member. . Each of the guide walls 68 and 70 is a strip-shaped plate member and extends horizontally at the height of the lateral displacement sensors 32 and 34 in a posture perpendicular to the platform 60. The fixed guide wall 68 is fixedly installed on the platform 60, but the movable guide wall 70 is
The fixed guide wall 68 is rotatably connected to one end of the fixed guide wall 68 about the axis of the shaft 72, and its free end is connected to the rear end of the side wall 74 of the container 66.
8 and the guide wall surface 46. Also, after the forklift 28 enters the container 66,
The wall surface of the container side wall 74 continuous with the movable guide wall 70 functions as a guide surface for guiding the forklift 28.

As is clear from FIGS. 7 and 8, the movable guide wall 70 is integrally provided with the vertical shaft 72 at the base end thereof, and the lower portion of the shaft 72 is a small diameter portion 76. , The small diameter portion 76 is fitted into the cylindrical post 78 that is erected on the platform 60, so that the shaft 72
Is rotatably supported around the axis of the. The front end of the fixed guide wall 68 is butted so as to come very close to the shaft 72.

Further, a small diameter portion 80 is integrally formed on the upper portion of the shaft 72, and a rotary potentiometer 84 is connected to the small diameter portion 80 via a coupling 82, and its main body is fixed to the fixed guide wall 68 by a bracket 86. It is fixed. The rotary potentiometer 84 is used for the movable guide wall 7
It serves as an angle detecting means for detecting a rotation angle of the fixed guide wall 68 of 0 with respect to the reference position where the fixed guide wall 68 and the movable guide wall 70 are aligned in a straight line, and is clockwise (clockwise) and counterclockwise. As is well known, the (counterclockwise) angle is detected by utilizing the change in the electric resistance value corresponding to the rotation angle.

The rotary potentiometer 84 is the ground station 88 shown in FIG.
9 is connected to a microprocessor (CPU: central processing unit) 90 shown in FIG. 9 via an I / O interface 92, and the side shift cylinder according to the angle signal of the rotary potentiometer 84. The side shift amount by 26 is determined. That is, a memory 94 is connected to the CPU 90, and the rotary potentiometer 84 is connected to the memory 94.
Of a plurality of types of shift data representing stepwise different side shift amounts according to the angle signal of
The U 90 is adapted to read from the memory 94 one of the shift data suitable for the U 90 according to the angle signal from the rotary potentiometer 84. In this example, the CPU 90 constitutes a side shift amount determining means together with the memory 94.

As is apparent from FIG. 1, the fixed guide wall 68 has four light projectors 96, 98, 1 arranged in the front-rear direction.
00 and 102 are fixed at positions deviated from the movement loci of the lateral displacement sensors 32 and 34, and are connected to the I / O interface 92 shown in FIG. on the other hand,
On the side of the vehicle body 2 of the forklift 28, the bracket 1
04, the four light receivers 106, 108, 110 and 112 are fixed to the fixed guide wall 68 at positions where the optical axes of the light receivers 106, 108, 110 and 112 can coincide with each other. It is connected to an on-vehicle microprocessor (CPU) 120 provided in the vehicle 28 via an I / O interface 124.

Emitters 96, 98, 100 and light receivers 106, 108, 1
One set out of three sets of 10 and 10 is for transmitting information on which of the left and right sides the movable guide wall 70 is to the fixed guide wall 68 by an ON / OFF signal by light, The remaining two sets are for transmitting shift data representing the side shift amount according to the angle of the movable guide wall 70 with respect to the fixed guide wall 68 by a combination of ON / OFF signals by light. In this case, 2
It is possible to transmit four different types of shift data by combining a set of light emitters and light receivers.

The light projector 102 and the light receiver 112 are for detecting that all three sets of the light emitter and the light receiver are aligned on the same optical axis.
The position where 00 and the light receivers 106, 108, 110 coincide with each other is the loading position in this example,
The light projector 102 and the light receiver 112 are provided by the forklift 28.
It also serves as an optical sensor for detecting that the fork insertion into the load W has been completed.

In FIG. 1, 114 is a drive motor for driving the drive wheels 4, and the drive motor 114 has
A travel distance sensor 116 is provided for calculating the number of revolutions of the output shaft and detecting the travel distance from the loading position of the forklift 28. The travel distance sensor 116 is provided.
Is also connected to the I / O interface 124 on the vehicle. As described above, the CPU 120 is connected to the I / O interface 124 together with the memory 122.
Various sensors necessary for unmanned control of the forklift 28, including the linear potentiometer 48 of the lateral displacement sensors 32 and 34, are connected.

The I / O interface 124 further includes the travel control circuit 1
40, a steering control circuit 142, a brake control circuit 144 and a cargo handling control circuit 146 are connected, and the drive motor 114 for driving the drive wheels 4 is connected to the traveling control circuit 140, and the steering control circuit 142 is connected.
Steering motor 150 for steering the steering wheel 6
Are connected. The brake control circuit 144 also includes
An electromagnetic brake 152 that controls the motor shaft of the drive motor 114 is connected, and an electromagnetic valve 156 that controls the hydraulic pressure to the hydraulic brake 154 that brakes each drive shaft 4 is connected. In the cargo handling control circuit 146,
An electromagnetic valve 158 that controls the supply of hydraulic pressure to the lift cylinder 22, the tilt cylinder 24, the side shift cylinder 26, and the like is connected. By controlling the operation of the electromagnetic valve 158, the fork 12 and the lift bracket are connected. The operation of the cargo handling device 160 including 18 will be controlled. Further, the CPU 120 processes the operation signals of various sensors and switches such as the lateral displacement sensors 32 and 34 described above in accordance with a program stored in advance in the memory 122 to steer, accelerate, decelerate and stop the forklift 28. Automatic control of temporary standby, automatic transfer, etc.

Next, such an unmanned guidance program for the forklift 28 will be described with reference to the flowchart shown in FIG.

First, as shown in FIG. 10 or FIG. 11, after the container 66 is retrofitted to the platform 60, the free end of the movable guide wall 70 is connected to the rear end of the side wall 74 of the container 66. The container 66 is positioned with the side wall 74 of the container 66 being positioned substantially on the extension line of the fixed guide wall 68. However, even if the position of the container 66 relative to the platform 60 is deviated, the deviation is caused by the movable guide wall 70.
It is absorbed by the rotation of the shaft 72 of the shaft.

The angle of the movable guide wall 70 with respect to the fixed guide wall 68 is detected by the rotary potentiometer 84 shown in FIG. 7 in step S1, and the angle signal is C on the ground in FIG.
It is sent to the PU 90. Then step S2 is executed,
The CPU 90 selects the optimum shift data from the plurality of side shift data stored in the memory 94 according to the angle signal of the rotary potentiometer 84.

On the other hand, the forklift 28 uses the chain conveyor 62.
Until the load W is sent by, it is kept waiting at the standby position behind the loading position, but when the predetermined sensor detects that the load W has been sent to the loading position, The fork 12 is inserted into the fork insertion groove or the pallet of the load W while moving forward from the standby position toward the loading position. Completion of the insertion is detected by the light receiver 112 receiving the light from the role light device 102 shown in FIG. 1, and the CPU 120 on the vehicle drives the drive motor 114 based on the detection signal of the light receiver 112. The electromagnetic brake 152 and the hydraulic brake 154 are stopped while being stopped.
Is operated to stop the forklift 28 at the loading position which is the insertion completion position shown in FIG. At this time, the projectors 96, 98, 100 provided on the fixed guide wall 68.
And the light receivers 106, 108, 110 provided on the vehicle body 2 face each other, and step S3 is executed in this state, and ON / O by the light from the light receivers 96, 98, 100 is performed.
By detecting the FF signal by the light receivers 106, 108, 110, the angle direction data of the movable guide wall 70 and the side shift data selected by the CPU 90 on the ground are transmitted to the CPU 120 on the vehicle, and the shift data and the like are stepped. It is stored in the memory 122 in S4.

By further executing step S5, the traveling distance sensor 116 is turned on, and in the following step S6, whether the movable guide wall 70 is angled to the right or left with respect to the fixed guide wall 68. To be judged. When it is determined that the right shift angle is present as shown in FIG. 10, step S7 is executed and the side shift cylinder 26 is operated while the forklift 28 lifts the load W at the insertion completion position shown in FIG. The fork 12 is operated and side-shifted to the right with respect to the lift bracket 18 and the like via the side-shift attachment 19 together with the load W. That is, the CPU 120 on the vehicle converts the shift data into an actual side shift amount (command value) based on the shift data transmitted from the CPU 90 on the ground and stored in the memory 122, and the cargo handling control circuit 146 and the electromagnetic valve. By operating the side shift cylinder 26 via 158, the load W is side-shifted to the right by the command value from the origin, that is, the vehicle center position. This side shift amount is necessary and sufficient for avoiding contact between the front end corner portion of the load W and the movable guide wall 70 until the lateral displacement sensor 32 on the front side of the forklift 28 detects the movable guide wall 70. It is considered as the shift amount. When the forklift 28 starts traveling and the lateral displacement sensor 32 detects the movable guide wall 70 to cause an output difference with the linear potentiometer 48 of the lateral displacement sensor 34 on the rear side, the CPU 120 causes the steering control circuit. The steering motor 150 is operated via 142 to steer the forklift 28 along the movable guide wall 70.

The travel distance of the forklift 28 from the loading position is determined by the CPU based on the signal from the travel distance sensor 116.
120 is calculated, and it is determined in step S8 whether the traveling distance K has become K ₁ . This mileage K ₁
Is set as a distance required for both the lateral displacement sensors 32 and 34 of the forklift 28 to contact the movable guide wall 70 in FIG. When the traveling distance of the forklift 28 reaches K ₁ , step S9 is executed, and the CPU 120 operates the side shift cylinder 26 in the opposite direction from step S7 by the same amount to shift the load W from the right shift position to the left side. Shift back to the origin.

Further, in step S10, it is determined whether the traveling distance K of the forklift 28 has reached K ₂ . The traveling distance K ₂ is a distance at which the front end of the load W reaches the rear end of the container 66. If the forklift 28 moves forward in this state, the right front corner of the load W contacts the right side wall of the container 66. If it is determined that the traveling distance has reached K ₂ in order to avoid this, the side shift cylinder 26 is actuated to side-shift the load W from the origin to the left by the command value in step S11. Is executed. This side shift amount to the left is determined by step S
7, which is the same as the side shift amount to the right, and is performed by a command from the CPU 120 based on the side shift data stored in the memory 122. Furthermore, the right in step S12, the travel distance K reaches K _3, if the forklift 28 is determined to become along the container sidewall 74, by the step S13 is executed, the load W from left shift position It is side-shifted and returned to the origin. After that, the forklift 28 is advanced to the unloading position along the container side wall 74.

On the other hand, as shown in FIG. 11, when the movable guide wall 70 is angled to the left with respect to the fixed guide wall 68,
The determination result of step S6 is NO, and the forklift 28 moves the movable guide wall 70 while supporting the load W at the origin.
When it is determined that the traveling distance has reached K ₂ in step S14, the load W is moved to the right by the shift amount (command value) corresponding to the side shift data stored in the memory 122. The step S15 of shifting is executed, and the contact between the cargo W and the container side wall 74 is avoided. Further, if it is determined that the mileage has reached K ₃ in step S16, the load W is side-shifted from the right shift position to the left and brought to the origin in step S17. Move forward.

In either case, after the forklift 28 reaches the unloading position and unloads the load W, the forklift 28 is held at the origin and then the forklift 28 moves toward the container side wall 7.
4, It moves backward along the movable guide wall 70 and the fixed guide wall 68, and returns to the above-mentioned standby position. Hereinafter, by repeating the same process, the loads W are sequentially loaded from the platform 60 into the container 66. In addition,
Even if the loads W are sequentially unloaded from the container 66, the control is essentially the same.

As is clear from the above description, the movable guide wall 70 is rotatably connected to the fixed guide wall 68, and the movable guide wall 70 is connected to the container side wall 74. There is no problem even if the post-installed position with respect to the platform 60 is displaced or varied, and the load W is side-shifted according to the angle of the movable guide wall 70 to avoid contact between the movable guide wall 70 and the load W. Therefore, the degree of freedom of guidance can be increased while protecting the cargo W.

In the embodiment described above, the CPU 90 and the memory 9 on the ground are used.
The side shift amount determining means such as No. 4 and the side shift attachment 19 mainly including the side shift cylinder 26 are provided with the load W according to the detection value of the rotary potentiometer 84.
The load position control means for controlling the left and right position of the vehicle is constructed. However, the detection value of the rotary potentiometer 84 is processed into a digital amount and the transmission means utilizing light or the like is used to detect the C on the vehicle.
It is also possible to transmit to the PU 120 and have the CPU 120 on the vehicle determine the side shift amount. Further, instead of the rotary potentiometer 84 as the angle detecting means, for example, a resolver that electromagnetically converts the angular displacement into an electric signal, or a rotary encoder that measures the rotational angle as a digital amount can be used.

In addition, the guide surface for guiding the forklift 28 unmanned is not limited to a flat wall surface, for example, in a case where the container is not loaded and unloaded, but is transported on the premises. For example, a guide rail having a circular cross section is used as a roller. A curved surface may be used as the guide surface in the case of guiding while contacting each other.
Further, as the guide surface detecting means for detecting the guide surface,
The lateral displacement sensors 32 and 34 are not limited to the contact type, but a non-contact type such as an ultrasonic sensor may be used.

In addition, although the present invention is preferably applied to an unmanned forklift guidance device, other unmanned vehicles without a cargo handling device may be used as long as they are guided unmanned by placing a load on the front part of the vehicle. It can be applied to a transport vehicle as well.

Although not described in detail one by one, it is needless to say that the present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing an example in which the present invention is applied to an unmanned forklift guidance device, and FIG. 2 is a side view of the forklift. FIG. 3 is an enlarged sectional view showing a part of FIG. 1 taken out, and FIG.
FIG. 4 is a sectional view taken along the line IV-IV in the figure. FIG. 5 is a plan view schematically showing an example of the usage of the forklift, and FIG. 6 is a side view thereof. 7 is a side view showing a connecting portion between the fixed guide wall and the movable guide wall in FIG. 1, and FIG. 8 is a partial sectional view showing a part of FIG. 7. FIG. 9 is a block diagram schematically showing a control circuit for guiding the forklift shown in FIG. 10 and 11 are plan views showing different guide modes of the forklift, and FIG. 12 is a flow chart showing the guide program of the forklift. 2: Vehicle body, 12: Fork 14: Outer mast, 16: Inner mast 18: Lift bracket 19: Side shift attachment 20: Finger bar 26: Side shift cylinder 28: Unmanned forklift (unmanned transport vehicle) 30: Guide wall 32, 34: Side Displacement sensor (guide surface detection means) 44: Linear potentiometer 46: Guide wall surface (guide surface) 60: Platform, 66: Container 68: Fixed guide wall (fixed guide member) 70: Movable guide wall (movable guide member) 72: Shaft , 74: Container side wall 84: Rotation potentiometer (angle detection means) 90, 120: Microprocessor (CPU: Central processing unit) 92, 124: I / O interface 94, 122: Memory 96, 98, 100, 102: Projector 106 , 108, 10,112: the receiver

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Honda 1-chome, Toyota-cho, Kariya city, Aichi Prefecture Toyota Industries Corporation (72) Inventor Tetsuo Tada 1-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd. (72) Inventor Akira Okura 1 Toyota-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd.

Claims (2)

[Claims] 1. An apparatus for guiding an unmanned transport vehicle having a load on its front part by means of lateral guide surfaces, which is rotatably connected to an end of a fixed guide member provided on the ground around a vertical line. A movable guide member that constitutes the guide surface together with the fixed guide member; guide surface detection means that is provided in the unmanned transport vehicle and detects the guide surfaces of the both guide members; and the fixed guide of the movable guide member. Angle detecting means for detecting a rotation angle with respect to the member, and changing the position of the load in the left-right direction in accordance with the angle detected by the angle detecting means, and contact the load with the guide surface of the possible guide member. An unmanned guided vehicle guidance device including a load position control means to avoid. 2. The unmanned transportation vehicle is a forklift truck having a fork for loading a load on a front portion thereof and a side shift attachment for side-shifting the fork and the load in the left and right direction of the vehicle, the load position control means. 2. The apparatus according to claim 1, further comprising: the side shift attachment and a side shift amount determining unit that determines a side shift amount of the attachment according to a detection value of the angle detecting unit.