JP2003291820A - Carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrier capable of preventing each wheel from giving large impact to a road surface and preventing each wheel from rising up to run by corresponding to each recessed and projecting part on the road surface flexibly even when the carrier runs on the road surface having recessed and projecting parts. <P>SOLUTION: This carrier is constituted in such a way that wheel support parts 13, 23 which are long in the forward and backward directions and turn vertically centered on a halfway part in the forward and backward directions are arranged on the right and left sides, load sensors 11s, 12s, 21s, 22s for detecting load received by wheels 11, 12, 21, 22 supported by the wheel support parts 13, 23 in the front and rear parts, respectively, are provided, and a running control means 32b controls running speed of each wheel 11, 12, 21, 22 based on the load detected by each load sensor 11s, 12s, 21s, 22s. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is long in the front-back direction,
The present invention relates to a trolley in which wheel supports that rotate up and down around a midway portion in the front-rear direction are arranged on the left and right, and wheels are provided at the front and rear parts of the wheel support.

[0002]

2. Description of the Related Art A truck having four wheels arranged in front, rear, left and right of a vehicle body and a motor for rotating each wheel, and by automatically driving each motor, each wheel rotates to automatically travel. Is known, and is used as a means for transporting goods and the like from a predetermined position to a predetermined position in a factory. By using the carriage that conveys the conveyed goods by such automatic traveling, it is possible to use it in a dangerous zone for humans without requiring manpower and to improve work efficiency. Each wheel provided in the above-mentioned bogie rotates while receiving a load corresponding to the load exerted on the road surface by itself, and even when traveling on a road surface having a certain degree of unevenness, unevenness is caused by the rotational force of each wheel. You can drive according to.

[0003]

However, in the above-mentioned bogie, when traveling on a road surface having an upward step portion having a step of at least half the outer diameter of the wheel provided for itself, the front wheels are placed on the step portion. A collision occurs and the front wheel receives a load in the opposite direction to the traveling direction from the step portion due to this collision, and therefore cannot cross the step portion. In addition, when traveling on a road surface having a downward step portion having a step that is equal to or more than half the outer diameter of the wheel, even if one of the front wheels passes through the step portion, the vehicle travels above the step portion for a while. The three front wheels keep the posture, and the front wheel runs in a floating state. When the other front wheel passes through the step, the two front wheels fall to the lower side of the step. Will end up. As a result, each front wheel gives a big impact to the lower side of the stepped portion, and at the same time the dolly receives a big impact, so that the luggage etc. mounted on the dolly may drop and the dolly itself may fall down. There was a problem.

The present invention has been made in view of the above circumstances, in which wheel supports that are long in the front-rear direction and that rotate up and down around a middle portion in the front-rear direction are arranged on the left and right, and one of the wheel supports is By providing speed control means for controlling the rotation speed of the supported wheel to be faster or slower than the rotation speed of the wheel supported by the other wheel support, the rotation speed of each wheel supported by the left and right wheel supports is different. Occurs, and the trolley body is twisted due to this difference. An object of the present invention is to provide a trolley in which each wheel support is rotated by the twist of the trolley body, and the wheels supported by the wheel support can be appropriately moved in the vertical direction by the rotation of the wheel support. And

Another object of the present invention is to provide a judging means for detecting an external force received by each wheel and judging whether the detected external force is larger or smaller than a predetermined range. , Based on the result judged by the judging means,
By being configured to control the rotational speed of the wheel that receives the external force and the wheel supported by the same wheel support as the wheel to be faster or slower than the rotational speed of the wheel supported by another wheel support, The rotation speed of each wheel supported by the left and right wheel supports varies depending on the external force received by each wheel, and the trolley body is twisted based on this difference, and the twisting of the trolley body causes each wheel support to rotate. The wheels supported by the wheel support can move vertically as appropriate, and each wheel exerts a large impact on the road surface even when traveling on the road surface having unevenness and grooves. It is an object of the present invention to provide a dolly that travels flexibly in response to each unevenness and groove on the road surface without causing each wheel to float.

Still another object of the present invention is to further provide a structure for controlling the above-mentioned other wheel support so as not to rotate, so that a desired wheel support can be rotated more easily. A desired wheel supported by the wheel support can move up and down more easily, and even when traveling on a road surface having unevenness and grooves, the unevenness and grooves on the road surface It is to provide a bogie that flexibly travels.

Still another object of the present invention is to provide a step detecting means for detecting a step, and to control the rotational speed of each wheel based on the step detected by the step detecting means, so that the step to be moved up and down. Each wheel support is rotated by an appropriate angle in accordance with the twisting of the bogie main body caused by the difference in the rotational speeds of the left and right wheels, which is controlled according to the height of the wheel, and the rotation of the wheel support causes the wheels to rotate. A trolley in which each wheel flexibly responds to each unevenness on the road surface, even when the wheels supported by the support can move in the vertical direction by an appropriate distance and travels on the uneven road surface. To provide.

Still another object of the present invention is that the axle of each wheel is arranged at an appropriate distance from the wheel support that supports the wheel, so that the rotation speeds of the left and right wheels are different. It is an object of the present invention to provide a trolley in which the wheel support can be rotated more easily and the wheels can be moved in the vertical direction more easily.

[0009]

A trolley according to the first invention is
A wheel support that is long in the front-rear direction and that rotates up and down about a midway portion in the front-rear direction is arranged on the left and right, and one wheel support is supported by a bogie having wheels on the front and rear portions of the wheel support. It is characterized by further comprising speed control means for controlling the rotational speed of the wheel to be faster or slower than the rotational speed of the wheel supported by the other wheel support.

In the case of the first invention, it is long in the front-back direction,
The wheel supports that rotate up and down around the middle part in the front-rear direction are arranged on the left and right, and the rotation speed of the wheels supported by one wheel support is higher than the rotation speed of the wheels supported by the other wheel support. By providing the speed control means for controlling fast or slow, the rotational speeds of the wheels supported by the left and right wheel supports differ from each other, and the truck body is twisted based on this difference. It is possible to realize a trolley in which each wheel support is rotated by the twist of the trolley body, and the wheels supported by the wheel support can be appropriately moved in the vertical direction by the rotation of the wheel support. .

A trolley according to a second aspect of the present invention is the trolley according to the first aspect of the invention, wherein external force detecting means for detecting an external force received by each of the wheels and whether the external force detected by the external force detecting means is larger than a predetermined range or not. Or a judgment means for judging whether or not it is small, the speed control means, based on the judgment result judged by the judgment means, of the wheel receiving the external force and the wheel supported by the same wheel support body as the wheel. It is characterized in that the rotation speed is controlled to be faster or slower than the rotation speed of a wheel supported by another wheel support.

According to the second aspect of the invention, the speed control means is provided with a judging means for detecting an external force received by each wheel and judging whether the detected external force is larger or smaller than a predetermined range. Based on the result determined by the determination means, the rotation speed of the wheel that receives the external force and the wheel supported by the same wheel support as the wheel is faster or slower than the rotation speed of the wheel supported by another wheel support. By being configured to control, the rotation speed of each wheel supported by the left and right wheel supports varies depending on the external force received by each wheel,
Due to this difference, the carriage main body is twisted, and the twisting of the carriage main body causes each wheel support body to rotate, and the wheels supported by the wheel support body can appropriately move in the vertical direction.

Therefore, even when the vehicle travels on a road surface having irregularities, grooves, etc., each wheel does not exert a large impact on the road surface and each wheel on the road surface does not float. It is possible to realize a truck that flexibly travels in response to unevenness and grooves. Further, each wheel is traveling on a flat road surface while receiving an external force in a predetermined range, and whether the external force received by each wheel detected by the external force detecting means is larger or smaller than the predetermined range. By providing the determination means for determining, it is possible to detect that the wheel that has received the external force has collided with the step portion to the upper front when the determination means determines that it is larger than the predetermined range. When the determination means determines that the size is smaller than the predetermined range, it is possible to detect that the wheel receiving the external force has begun to descend the front step portion.

A trolley according to a third aspect of the present invention is the trolley according to the first or second aspect of the invention, in which the other wheel support is not rotated when the determination means determines that it is larger or smaller than the predetermined range. It is characterized by further comprising a rotation control means for controlling.

In the case of the third invention, a desired wheel support can be rotated more easily by further providing a structure for controlling the other wheel support in the first or second invention so as not to rotate. The desired wheel supported by the wheel support can move in the vertical direction more easily, and even when traveling on a road surface having unevenness and grooves, each unevenness on the road surface Also, it is possible to realize a cart that travels flexibly in the groove.

A trolley according to a fourth aspect is the trolley according to any one of the first to third aspects, further comprising step detecting means for detecting a step, and the speed control means detects the step detected by the step detecting means. Based on this, the rotation speed of each of the wheels is controlled.

In the case of the fourth aspect of the present invention, the step detecting means for detecting the step is provided, and the rotation speed of each wheel is controlled based on the step detected by the step detecting means. Each wheel support is rotated by an appropriate angle in accordance with the twist of the bogie main body caused by the difference in the rotational speeds of the left and right wheels, which is controlled according to the degree of the wheel support, and the rotation of the wheel support causes the wheel support to rotate. The wheels supported by can move up and down by an appropriate distance. Therefore, even when traveling on a road surface having a stepped portion including a groove or the like, a large impact is exerted on the road surface by moving each wheel in the vertical direction by an appropriate distance according to the step detected in advance. It is possible to realize a bogie that travels flexibly in response to each step on the road surface without exerting any influence and without causing the wheels to float.

A trolley according to a fifth aspect of the present invention is the trolley according to any of the first through fourth aspects of the invention, wherein the axle of the wheel is arranged at an appropriate distance from the wheel support that supports the wheel. It is characterized by

According to the fifth aspect of the invention, the axle of each wheel is
By arranging the wheel supporter that supports the wheel at an appropriate interval, the wheel supporter can be more easily rotated due to the difference in the rotational speeds of the left and right wheels, and the wheel is It is possible to realize a cart that can move in the vertical direction more easily.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A bogie according to the present invention will be described in detail below with reference to the drawings showing an embodiment thereof. FIG. 1 is a perspective view showing a carriage according to the present invention, FIG. 2 is a front view, and FIG. 3 is a side view. In the figure, reference numeral 1 denotes a trolley, and the trolley 1 has a trolley body 30 on which a control device 32 for controlling the trolley itself is mounted, and two pedestals 10, 2 at the bottom of the trolley body 30.
0 and a main body support portion 31 that supports the trolley main body 30 while holding the two leg portions 10 and 20 in the middle portions thereof.

The leg portion 10 has a plate-like wheel support portion 13 which is long in the front-rear direction of the carriage 1, and the load sensor 1 is provided at the front and rear portions thereof, respectively.
The wheels 11 and 12 are rotatably supported through the wheels 4 and 15. The axles of the wheels 11 and 12 are arranged at appropriate intervals from the wheel support portion 13. The wheels 11 and 12 are configured to rotate separately, and the wheel motors 11m and 12m for rotating the wheels 11 and 12 and the rotation angles of the wheels 11 and 12 are detected on the rotation axes of the wheels 11 and 12, respectively. Wheel sensors 11s, 12
s. The wheel support portion 13 is configured to be rotatable about a middle portion in the front-rear direction as a rotation shaft 13a, and the wheel support portion 13 is rotated on the rotation shaft 13a of the wheel support portion 13. Support section motor 13m and support section sensor 13s for detecting the rotation angle of the wheel support section 13
Is equipped with.

The leg portion 20 has the same structure as that of the leg portion 10 described above, and a plate-shaped wheel support portion 23 which is long in the front-rear direction of the carriage 1 has load sensors 24 and 25 at its front and rear portions, respectively. The wheels 21 and 22 are supported through the wheels. Also, the wheel 2
Wheel motors 21m and 22m for rotating the wheels 21 and 22 and the wheels 21 on the rotation shafts of the wheels 21 and 22, respectively.
A wheel sensor 21s for detecting the rotation angle of 22;
22s is mounted on the rotation shaft 23a of the wheel supporting portion 23, and is a support portion motor 23m for rotating the wheel supporting portion 23.
And a support portion sensor 23s for detecting the rotation angle of the wheel support portion 23.

The two leg portions 10 and 20 are supported by the vehicle body support portion 31 by holding the support portion sensors 13s and 23s arranged on the rotation shafts 13a and 23a of the wheel support portions 13 and 23, respectively. , Which are arranged at the left and right positions of the carriage 1, whereby the wheels 11 and 12 provided on the leg 10 are
Similarly, the wheels 21 and 22 provided on the leg 20 function as front wheels and rear wheels, respectively, and function as front wheels and rear wheels, respectively. A battery (not shown) is mounted on the trolley body 30, and the controller 3 is supplied with power from the battery.
2 operates, and the above-described units provided in the carriage 1 operate under the control of the control device 32.

FIG. 4 is an explanatory view showing a rotation mode of the wheel support section 13 provided on the carriage 1. In the figure, a mode in which the direction indicated by an arrow A is used as a traveling direction and a step portion forwardly and upwardly is overcome is shown. Shows. In the figure, the rotation speeds of the wheels 11 and 12 arranged on the left side in the traveling direction are controlled to be higher than the rotation speeds of the wheels 21 and 22 arranged on the right side. Truck 1 based on the difference
Twisting occurs in each wheel supporting portion 1 due to the twisting of the carriage 1.
3, 23 rotate. The right wheel support 23 that does not get over the step is controlled so as not to rotate, whereby the wheel support 13 rotates by an angle indicated by θ in the figure, and the wheel 11 moves upward. I understand. On the contrary, the rotational speeds of the left wheels 11 and 12 are changed to the right wheel 2
When the rotation speed is controlled to be slower than the rotation speeds of the wheels 1 and 22, the left wheel support portion 13 rotates in the opposite direction and the wheels 11 can move downward.

FIG. 5 is a block diagram showing the structure of the carriage 1 according to the present invention. The control device 32 provided in the truck 1 is specifically configured by an MPU (Micro Processor Unit) or the like, and the wheel sensors 11s, 12s, 21s, 2 provided in the truck 1 are provided.
2s, support section sensors 13s and 23s, load sensor 1
4, 15, 24, 25, wheel motors 11m, 12m,
21m, 22m and motors 13m, 23m for the support are respectively connected. The control device 32 uses the wheel sensor 11
Wheels 11, 1 detected by s, 12s, 21s, 22s
2, 21 and 22 rotation angles, support section sensors 13s, 2
Rotation angles of the wheel supporting portions 13 and 23 detected by 3s and the respective wheels 1 detected by the load sensors 14, 15, 24 and 25
The motors for wheels 11m, 12m, 21m, 22m that sequentially acquire the loads received by the 1, 12, 21, 21 and rotate the wheels 11, 12, 21, 22 based on the acquired values.
Also, an impedance control means 32a and a travel control means 32b are provided in order to control the driving force for driving the support portion motors 13m, 23m for rotating the wheel support portions 13, 23.

The traveling control means 32b, based on the data from each sensor acquired by the control device 32, each wheel 11, 1
Wheel motors 11m, 12 for rotating 2, 21, 22
The driving force of m, 21 m, and 22 m is controlled, and when traveling on a flat road surface, each motor is driven with a predetermined driving force. In addition, when the traveling control means 32b determines that one wheel crosses over the front step,
When the driving force of each wheel motor is controlled to 0 so that the rotation speeds of the one wheel and the two wheels arranged at the left and right positions become zero, and one wheel descends the step portion to the front and lower side. When the determination is made, the driving force of each wheel motor is controlled so that the rotation speeds of the one wheel and the two wheels arranged at the left and right positions are increased by a predetermined speed. The left and right wheels are controlled by controlling the rotation speeds of the wheels that move up and down the step and the wheels that are supported by the same wheel support portion as the wheels to be faster or slower than the rotation speeds of the wheels that are supported by the other wheel support portions. The configuration is not limited to the configuration in which only the rotational speeds of the wheels on the side that does not move up and down the stepped portion are controlled as described above as long as the rotational speeds differ.

The impedance control means 32a controls the driving force of the support portion motors 13m and 23m for rotating the wheel support portions 13 and 23 by impedance control processing based on the data from the respective sensors. Here, the impedance control process is generally performed by adjusting each impedance characteristic M, D, and K represented by the following equation (1) to set the control target to the equilibrium point position x _d in impedance control. This is a process of controlling the driving force F required to reach the target.

[0028]

[Equation 1]

The impedance control means 32a in the present embodiment controls the driving force F of the support portion motors 13m and 23m for rotating the wheel support portions 13 and 23 as described above, and in the formula (1). The equilibrium point position x _d and the current position x mean the target rotation angle θ _d and the current angle θ of the wheel support portions 13 and 23, respectively. Further, in the present embodiment, the mass characteristic M is the mass of the carriage main body 30,
Since the damping characteristic D is a mechanical characteristic that the wheel supporting portions 13 and 23 have in advance, the impedance control means 32a
By adjusting the rigidity characteristic K expressed by the following equation (2), the driving force F of the support unit motors 13m and 23m is controlled. The mass characteristic M and the damping characteristic D may be adjusted.

K (θ-θ _d ) = F (2) (K: rigidity characteristic, θ _d : equilibrium point position, θ: current position)

The rigidity characteristic K adjusted by the impedance control means 32a is the spring constant of a virtual spring virtually provided for moving the wheels 11, 12, 21, 22 in the vertical direction. By setting the constant to a smaller value, a smaller force is applied to each wheel 11, 1
2, 21, 22 can move in the vertical direction. In the present embodiment, this spring constant is changed sequentially when traveling on a flat road surface, when moving up and down the stepped portion, and when not moving up and down the stepped portion, and the respective spring constants K ₀ , K ₁ , K. ₂ (0 <K ₁ <K ₀ <K ₂ ) is stored in advance. On the other hand, in equation (2) above, the equilibrium point position θ
_d indicates a position where the virtual spring has a natural length, that is, a position where the wheel support portions 13 and 23 are stable without rotating. Therefore, when the wheel support parts 13 and 23 deviate from the target rotation angle θ _d , the impedance control means 32a operates the support part motors 13m and 23m by the driving force F calculated based on the above equation (2). By driving, each wheel 11, 12, 21, 22 can travel stably while flexibly responding to the unevenness on the road surface.

The load sensors 14, 15, 24, 25 detect the loads received by the wheels 11, 12, 21, 22 from the road surface, respectively. When the truck 1 is traveling on a flat road surface, The wheels 11, 12, 21, 22 are subjected to a load within a predetermined range from the road surface. Therefore, the control device 32 in the present embodiment is configured so that the load sensors 14, 1
When 5, 24, 25 detect a load larger than this predetermined range, it recognizes that the wheel receiving this load has collided with the front step portion, and each load sensor 14, 1
When 5, 24, 25 detect a load smaller than the predetermined range, it is recognized that the wheel receiving the load has started to descend the front step portion.

Therefore, the impedance control means 32a
Is a small value K of the spring constant of the virtual spring in the wheel support portion that supports the wheel that moves up and down the front step portion based on the load detected by each load sensor 14, 15, 24, 25.
_1, to change the spring constant of the imaginary spring to a large value K ₂ of the other wheel support portion. Accordingly, the other wheel support portion does not rotate, and the wheel that moves up and down the step portion can easily move in the vertical direction along the step portion.

The process of getting over the stepped portion by the carriage 1 will be described below. FIG. 6 and FIG. 7 are flowcharts showing a procedure for getting over the stepped portion by the carriage 1 according to the present invention, and FIG.
FIG. 4 is an explanatory diagram for explaining a process of getting over a step portion by the carriage 1 according to the present invention. The trolley | bogie 1 is running on the road surface which has the step part B which goes to the front upwards by making the direction shown by the arrow C in FIG. Further, the trolley 1 is obliquely entering the stepped portion B, and the left front wheel first crosses the stepped portion B in the traveling direction. For convenience,
Left front wheel is wheel 11, left rear wheel is wheel 12, right front wheel is wheel 2
1, the right rear wheel is wheel 22.

In the trolley 1, on a flat road surface, the spring constant of a virtual spring for vertically moving the wheels 11, 12, 21, 22 is set to a magnitude K ₀ sufficient to absorb the unevenness of the road surface. , The target rotation angle of the wheel support portions 13 and 23 is the current angle θ ₀ arranged in the horizontal direction, and the support portion motor 13m that rotates the wheel support portions 13 and 23 based on the following equation (3). It is traveling while controlling the driving force of 23 m.

K ₀ (θ-θ ₀ ) = F (3)

Therefore, when the wheel support portions 13 and 23 deviate from the target rotation angle θ ₀ , the impedance control means 32 is provided.
By driving the support unit motors 13m and 23m with a by the driving force F calculated based on the above equation (3), the wheels 11, 12, 21, and 22 flexibly conform to the unevenness on the road surface. It is possible to cope with this, and the carriage 1 can travel stably. The control device 32 includes load sensors 14, 15,
Based on the load received from the road surface by each wheel 11, 12, 21, 22 detected by 24, 25, each wheel 11, 12, 2
It is determined whether or not the vehicles 1 and 22 have collided with the front stepped portion B (S1). Specifically, the load sensors 14, 15, 24,
It is determined whether the load detected by 25 is larger than a load within a predetermined range detected during traveling on a flat road surface, and when it is determined that the load is larger than the predetermined range, the wheel 11, which has received the load, It can be determined that the 21, 21 and 22 have collided with the front stepped portion B.

When the controller 32 determines that the wheel collides with the stepped portion B, it determines which wheel has collided with the stepped portion B based on the load detected by each load sensor 14, 15, 24, 25. , Determine which wheels need to ride over the stepped portion B (S2). FIG. 8A shows the dolly 1 in which the left front wheel 11 collides with the step portion B. In the present embodiment, the left front wheel 11, the right front wheel 21, the left rear wheel 12, and the right rear wheel 22 are stepped in this order. Get over Part B. Next, the control device 32 changes the rotation speed of each of the wheels 11, 12, 21, 22 depending on whether or not each of the front wheels 11, 21 is a wheel over the stepped portion B (S3). Specifically, the wheel motor 21 that rotates the right front wheel 21 and the right rear wheel 22 that does not climb over the stepped portion B
The driving forces of m and 22m are set to 0, and the rotational speeds of the right front wheel 21 and the right rear wheel 22 are set to 0.

Further, the control device 32 determines the spring constant in impedance control to be performed on the wheel support portions 13 and 23 supporting the front wheels 11 and 21, depending on whether or not the front wheels 11 and 21 are wheels overcoming the stepped portion B. Determine (S4).
Specifically, the spring constant of the wheel support portion 13 that supports the left front wheel 11 that rides over the stepped portion B is set so that the wheel support portion 13 can flexibly rotate according to the load received from the stepped portion B. ₁ , the spring constant in the wheel support portion 23 that supports the right front wheel 21 that does not get over the stepped portion B is
The spring constant K ₂ is set so that the wheel supporting portion 23 does not rotate with respect to the load received from the road surface.

The control device 32 controls the impedance control means 32 based on the spring constant in the impedance control process performed on the wheel support portions 13 and 23 changed as described above.
The driving force of the support portion motors 13m and 23m for rotating the wheel support portions 13 and 23 is calculated by a (S5), and the respective support portion motors 13m and 23m are calculated based on the calculated driving force.
23 m is driven (S6). By changing the spring constant as described above, the driving force of the supporting portion motor 13m for rotating the wheel supporting portion 13 is determined by the following formula (4) to rotate the wheel supporting portion 23. Motor 23
The driving force of m is calculated based on the following equation (5).

K ₁ (θ−θ ₀ ) = F (4) K ₂ (θ−θ ₀ ) = F (5)

In the impedance control means 32a, the left front wheel 11 has a stepped portion B on the basis of the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. It is determined whether or not the overcoming of is completed (S7). FIG. 8B shows the left front wheel 11
Indicates the truck 1 traveling on the stepped portion B, and the traveling control means 32b determines that the left front wheel 11 has finished passing over the stepped portion B at each rotational speed changed in step S3. , 12, 21, 22 are rotated.
It should be noted that when the ride over the stepped portion B of the left front wheel 11 is completed, the load detected by the load sensor 14 changes greatly. Therefore, by measuring the amount of change in the detected load, the stepped portion B of the left front wheel 11 can be measured. It is possible to judge whether or not the overcoming is completed.

FIG. 8 (c) shows the truck 1 in which the left front wheel 11 has passed over the stepped portion B, and in step S7, the control device 32 determines that the left front wheel 11 has completed passing over the stepped portion B. If so, all wheels 11, 12, 2
It is determined whether or not the wheels 1 and 22 have finished passing over the stepped portion B (S8). Here, only the front left wheel 11 has passed over the stepped portion B, and the control device 32 in the carriage 1 in which the front left wheel 11 travels above the stepped portion B is
The rotation speeds of 12, 21, 22 are changed to predetermined rotation speeds when traveling on a flat road surface (S9). Further, the control device 32 changes the spring constant in the impedance control performed on each wheel support 13, 23 to the spring constant K ₀ when traveling on a flat road surface (S10).

Next, the control device 32 controls the support part sensor 13
By s, the rotation angle (current angle) of the wheel support portion 13 up to the present when the left front wheel 11 gets over the stepped portion B is detected (S11), and the wheel support portion 1 that supports the left front wheel 11 is detected.
The target rotation angle in the impedance control performed in 3 is
The detected current angle is changed (S12). It should be noted that the left front wheel 11 gets over the step B and the wheel support 1
The rotation angle of 3 is θ ₁ (θ ₀ <θ ₁ ). The impedance control unit 32a calculates the driving force of the support unit motors 13m and 23m that rotate the wheel support units 13 and 23 based on the changed spring constant and the target rotation angle (S1).
3) Then, the supporter motors 13m and 23m are driven based on the respective calculated driving forces (S14), and the process returns to step S1. The driving force of the support portion motor 13m that rotates the wheel support portion 13 is calculated based on the following equation (6), and the support portion motor 23 that rotates the wheel support portion 23 is calculated.
The driving force of m is calculated based on the above formula (3).

K ₀ (θ-θ ₁ ) = F (6)

Each wheel 11, 12, 21, provided for the carriage 1,
The vehicle 22 travels on the upper side or the lower side of the stepped portion B, respectively, until the next wheel over the stepped portion B collides with the stepped portion B. The control device 32 causes the wheels 11, 12, 21, 22 to collide with the stepped portion B based on the load received by the wheels 11, 12, 21, 22 from the road surface detected by the load sensors 14, 15, 24, 25. If it is determined that the collision with the stepped portion B is made again (S1), each load sensor 14, 15, 2
Based on the load detected by Nos. 4 and 25, which wheel has stepped portion B
It is determined whether or not the vehicle has collided with, and the wheels that need to get over the stepped portion B are determined (S2). Here, the right front wheel 21 gets over the stepped portion B.

The controller 32 controls the wheel motor 1 for rotating the left front wheel 11 and the left rear wheel 12 which do not get over the stepped portion B.
The driving force of 1 m and 12 m is set to 0, and the rotational speeds of the left front wheel 11 and the left rear wheel 12 are set to 0 (S3). In addition, the control device 3
Reference numeral 2 denotes a spring whose spring constant in impedance control is performed on the wheel support portion 23 that supports the right front wheel 21 that rides over the stepped portion B, such that the wheel support portion 23 can flexibly rotate according to the load received from the stepped portion B. the constant K _1, the spring constant of the wheel support portion 13, the wheel support 13 to change the spring constant K ₂ of the size does not rotate with respect to the load received from the road surface (S4). The control device 32 determines the impedance control means 32 from the spring constant in the impedance control process performed on the wheel support parts 13 and 23 changed as described above.
The driving force of the support part motors 13m and 23m for rotating the wheel support parts 13 and 23 by a is as follows (7).
Formulas and the formula (4) above are used to calculate (S5), and the supporting unit motors 13m and 23 are calculated based on the respective calculated driving forces.
m is driven (S6).

K ₂ (θ-θ ₁ ) = F (7)

In the impedance control means 32a, the right front wheel 21 has a stepped portion B based on the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. When it is determined that the right front wheel 21 has completed overcoming the stepped portion B (S7), it is determined that all the wheels 11,
It is determined whether 12, 21, and 22 have completed passing over the stepped portion B (S8). Here, the front wheels 11 and 21 have only passed over the stepped portion B, and the control device 32 in the truck 1 in which the front wheels 11 and 12 travel above the stepped portion B is
The rotation speed of each wheel 11, 12, 21, 22 is changed to a predetermined rotation speed when traveling on a flat road surface (S
9). Further, the control device 32 controls the wheel support parts 13 and 23.
The spring constant in the impedance control performed in step ₁ is changed to the spring constant K ₀ when traveling on a flat road surface (S1).
0).

Next, the controller 32 controls the support sensor 23.
From s, the current angle θ ₁ of the wheel support 23 due to the right front wheel 21 getting over the step B is detected (S11),
The target rotation angle in the impedance control performed on the wheel support portion 23 that supports the right front wheel 21 is changed to the detected current angle θ ₁ (S12). The impedance control means 32a uses the changed spring constant and the target rotation angle based on the above equation (6) to support the motors 13m and 23 for the support portions.
The driving force of m is calculated respectively (S13), each of the supporter motors 13m and 23m is driven based on the calculated driving force (S14), and the process returns to step S1. In addition, trolley 1
Each of the wheels 11, 12, 21, 22 provided on the vehicle travels on the upper side or the lower side of the stepped portion B until the next wheel over the stepped portion B collides with the stepped portion B.

The control device 32 includes the load sensors 14, 15,
Based on the load received from the road surface by each wheel 11, 12, 21, 22 detected by 24, 25, each wheel 11, 12, 2
It is again determined whether or not the first and second wheels collide with the stepped portion B (S
1) When it is determined that the bump portion B has collided, it is determined which wheel collides with the bump portion B based on the load detected by each load sensor 14, 15, 24, 25, and the bump portion B is detected. The wheels that need to be overcome are determined (S2). Here, the left rear wheel 12 gets over the stepped portion B. Control device 32
Is a right front wheel 21 and a right rear wheel 22 that do not climb over the stepped portion B.
The driving forces of the wheel motors 21m and 22m for rotating the vehicle are increased by a predetermined amount to increase the rotational speeds of the right front wheel 21 and the right rear wheel 22 by a predetermined amount (S3).

Further, the control device 32 flexibly adjusts the spring constant in the impedance control performed on the wheel supporting portion 13 that supports the left rear wheel 12 over the step portion B according to the load received from the step portion B. The spring constant of the wheel support portion 23 is set to the spring constant K ₁ of a size that allows rotation,
The spring constant K ₂ is changed so that the wheel support 23 does not rotate with respect to the load received from the road surface (S4). The control device 32 uses the wheel support parts 13 and 23 modified as described above.
From the spring constant in the impedance control process to
Each wheel support unit 1 is controlled by the impedance control unit 32a.
The driving forces of the supporter motors 13m and 23m for rotating the motors 3 and 23 are calculated based on the following equation (8) and the above equation (7) (S5), and each is calculated based on the calculated driving force. The supporting unit motors 13m and 23m are driven (S6).

K ₁ (θ-θ ₁ ) = F (8)

The impedance control means 32a is arranged such that the left rear wheel 12 has a stepped portion based on the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. When it is determined that the left rear wheel 12 has passed over the stepped portion B, it is determined whether all the wheels 11,
It is determined whether 12, 21, and 22 have completed passing over the stepped portion B (S8). Here, the front wheels 11 and 21 and the left rear wheel 12 have only crossed over the stepped portion B.
1, 21 and the left rear wheel 12 travel on the upper side of the stepped portion B, the control device 32 in the trolley 1 is configured so that the wheels 11, 12, 2
The rotation speeds of 1 and 22 are changed to a predetermined rotation speed when traveling on a flat road surface (S9). In addition, the control device 3
2 changes the spring constant in the impedance control performed on each wheel support 13, 23 to the spring constant K ₀ when traveling on a flat road surface (S10).

Next, the control device 32 controls the support part sensor 13
By s, the current angle of the wheel support 13 due to the left rear wheel 12 getting over the step B is detected (S11), and the target rotation angle in the impedance control performed on the wheel support 13 supporting the left rear wheel 12 is determined. , The detected current angle is changed (S12). Here, the wheel supporting portion 13 is brought into a horizontal state by the rear wheel 12 moving above the stepped portion B, so that the target rotation angle of the wheel supporting portion 13 is a horizontal traveling surface on a flat road surface. The target rotation angle θ ₀ at that time is obtained.
The impedance control unit 32a calculates the driving force of each of the support unit motors 13m and 23m from the changed spring constant and target rotation angle based on the above equations (3) and (6) (S13). The supporting unit motors 13m and 23m are driven based on the respective calculated driving forces (S14), and the process returns to step S1. In addition, each wheel 1 provided for the trolley 1
1, 12, 21, and 22 travel on the upper side or the lower side of the stepped portion B, respectively, until the wheel which gets over the stepped portion B next collides with the stepped portion B.

The control device 32 includes load sensors 14, 15,
Based on the load received from the road surface by each wheel 11, 12, 21, 22 detected by 24, 25, each wheel 11, 12, 2
It is again determined whether or not the first and second wheels collide with the stepped portion B (S
1) When it is determined that the bump portion B has collided, it is determined which wheel collides with the bump portion B based on the load detected by each load sensor 14, 15, 24, 25, and the bump portion B is detected. The wheels that need to be overcome are determined (S2). Here, the right rear wheel 22 gets over the stepped portion B. Control device 32
Is a front left wheel 11 and a rear left wheel 12 that do not climb over the stepped portion B.
The driving force of the wheel motors 11m and 12m for rotating the vehicle is increased by a predetermined amount, and the rotational speeds of the left front wheel 11 and the left rear wheel 12 are increased by a predetermined amount (S3).

Further, the control device 32 flexibly adjusts the spring constant in the impedance control performed on the wheel support portion 23 supporting the right rear wheel 22 over the step portion B according to the load received from the step portion B. The spring constant of the wheel supporting portion 13 is set to the spring constant K ₁ of the size that allows the rotation.
The spring constant K ₂ is changed so that the wheel support 13 does not rotate with respect to the load received from the road surface (S4). The control device 32 uses the wheel support parts 13 and 23 modified as described above.
From the spring constant in the impedance control process to
Each wheel support unit 1 is controlled by the impedance control unit 32a.
The driving forces of the support unit motors 13m and 23m for rotating the motors 3 and 23 are calculated based on the above equations (5) and (8), respectively (S5), and each support unit is calculated based on the calculated driving force. The driving motors 13m and 23m are driven (S6).

In the impedance control means 32a, the right rear wheel 22 is stepped based on the load received from the road surface by each wheel 11, 12, 21, 22 detected by each load sensor 14, 15, 24, 25 at a predetermined cycle. When it is determined whether the ride over B has been completed (S7), and it is determined that the right rear wheel 22 has finished climbing over the stepped portion B, all the wheels 11,
It is determined whether or not 12, 21, 22 have completed getting over the stepped portion B (S8), and all the wheels 11, 12, 21, 2,
When 2 gets over the stepped portion B, the process of getting over the stepped portion B is ended.

As described above, when the front wheels pass over the stepped portion B, the motor for each wheel is controlled so that the rotation speed of each wheel supported by the wheel support portion other than the wheel support portion supporting the front wheel becomes zero. The front wheel that rides over the stepped portion B can move upward along the stepped portion B by controlling the. Also, when the rear wheel gets over the stepped portion B,
For each wheel such that the rotation speed of each wheel supported by the wheel support portion other than the wheel support portion supporting the rear wheel is higher than the rotation speed of each wheel supported by the wheel support portion supporting the rear wheel. By controlling the motor, the rear wheel that rides over the stepped portion B can move upward along the stepped portion B.

Furthermore, by setting the spring constant in the impedance control processing performed on the wheel support portion that supports the wheel that does not climb over the step portion B so that the wheel support portion does not rotate with respect to the load received from the step portion B, The wheel that rides over the stepped portion B can more easily rotate the wheel support portion that supports itself. Therefore, the wheels can more easily move upward along the stepped portion B and can get over the stepped portion B.

The process of lowering the stepped portion by the carriage 1 will be described below. 9 and 10 show a cart 1 according to the present invention.
11 is a flow chart showing a step of descending the step portion by FIG.
FIG. 6 is an explanatory diagram for explaining a descent process of a step portion by the trolley 1 according to the present invention. The trolley 1 travels on a road surface having a downward step D in the forward direction with the direction indicated by the arrow E in FIG. 11 as the traveling direction. In addition, the dolly 1 has
It is assumed that the left front wheel first descends from the step D with respect to the traveling direction. For convenience,
Left front wheel is wheel 11, left rear wheel is wheel 12, right front wheel is wheel 2
1, the right rear wheel is wheel 22.

The trolley 1 has wheels 11, 12, 21, 22.
The spring constant of a virtual spring for moving the wheel is set to a magnitude K ₀ sufficient to absorb the unevenness of the road surface, and the target rotation angle of the wheel support portions 13 and 23 is set to the current angle θ arranged in the horizontal direction. _{As 0} , the wheel support portion 1 is based on the above equation (3).
While controlling the driving force of the support unit motors 13m and 23m for rotating the motors 3 and 23, the vehicle travels on a flat road surface.
The control device 32 causes the wheels 11, 12, 21, 22 to detect the front step D based on the load received by the wheels 11, 12, 21, 22 from the road surface detected by the load sensors 14, 15, 24, 25. It is determined whether or not the descent has started (S2
1). Specifically, the load sensors 14, 15, 24, 25
It is determined whether the load detected by the load is smaller than the load within a predetermined range detected during traveling on a flat road surface. When it is determined that the load is smaller than the predetermined range, the wheel 1 that has received the load is determined.
It can be determined that the 1, 2, 21, 22 have begun to descend the front step D.

When it is determined that the control device 32 has begun to descend the step portion D, the load sensors 14, 15, 24, 25.
Based on the load detected by, which wheel has started to descend the step D is determined, and the wheel that needs to descend the step D is determined (S22). FIG. 11A shows the truck 1 in which the left front wheel 11 has begun to descend the step D. In the present embodiment, the left front wheel 11, the right front wheel 21, the left rear wheel 12, and the right rear wheel 22 are arranged in this order. The step portion D descends in sequence. Next, the control device 3
2 changes the rotation speed of each wheel 11, 12, 21, 22 depending on whether or not each front wheel 11, 21 is a wheel descending the step D (S23). Specifically, the driving forces of the wheel motors 21m and 22m that rotate the right front wheel 21 and the right rear wheel 22 that do not descend the step D are increased by a predetermined amount,
The rotation speeds of the right front wheel 21 and the right rear wheel 22 are increased by a predetermined speed.

Further, the control device 32 determines whether each front wheel 11 or 21 is a wheel descending the step D or not.
The spring constant in the impedance control performed on the wheel support portions 13 and 23 supporting the wheels 1 and 21 is changed (S24).
Specifically, the spring constant of the wheel support portion 13 that supports the left front wheel 11 that descends the step portion D is set so that the wheel support portion 13 can flexibly rotate according to the load received from the step portion D. K ₁ and right front wheel 2 that does not descend step D
The spring constant of the wheel support portion 23 supporting 1 is set to a spring constant K ₂ of such a magnitude that the wheel support portion 23 does not rotate with respect to the load received from the road surface.

The control device 32 controls the impedance control means 32 on the basis of the spring constant in the impedance control process performed on the wheel support portions 13 and 23 changed as described above.
The driving force of the support unit motors 13m and 23m for rotating the wheel support units 13 and 23 is calculated from a (S25),
The motor 13 for each support portion is calculated based on the calculated driving force.
m and 23m are driven (S26). The driving force of the support portion motor 13m for rotating the wheel support portion 13 by changing the spring constant as described above is the same as in (4) above.
Based on the equation, the driving force of the support portion motor 23m that rotates the wheel support portion 23 is calculated based on the above equation (5).

The impedance control means 32a determines that the left front wheel 11 has a step D on the basis of the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. It is determined whether or not the descent has been completed (S27). Fig. 11 (b) shows the left front wheel 11
Indicates the truck 1 that is descending the step D, and the traveling control unit 32b determines that the left front wheel 11 has completed the descent of the step D at each rotation speed changed in step S23. , 12, 21, 22 are rotated.
It should be noted that when the ride over the stepped portion B of the left front wheel 11 is completed, the load detected by the load sensor 14 changes greatly. Therefore, by measuring the amount of change in the detected load, the stepped portion B of the left front wheel 11 can be measured. It is possible to judge whether or not the overcoming is completed.

FIG. 11C shows the trolley 1 in which the left front wheel 11 has descended the step D, and in step S27,
When the control device 32 determines that the left front wheel 11 has completed the descent of the step D, all the wheels 11, 12, 21,
22 determines whether or not the descent of the step portion D has been completed (S
28). Here, only the left front wheel 11 has just descended the step D, and the control device 32 in the trolley 1 in which the left front wheel 11 travels below the step D is controlled by the wheels 11, 12, 2.
The rotation speeds of 1 and 22 are changed to a predetermined rotation speed when traveling on a flat road surface (S29). Further, the control device 32 changes the spring constant in the impedance control performed on the wheel support portions 13 and 23 to the spring constant K ₀ when traveling on a flat road surface (S30).

Next, the control device 32 controls the support part sensor 13
By s, the current angle of the wheel support 13 caused by the left front wheel 11 descending the step D is detected (S31), and the target rotation angle in the impedance control performed on the wheel support 13 supporting the left front wheel 11 is The detected current angle is changed (S32). The rotation angle of the wheel support portion 13 when the left front wheel 11 descends the step D is θ ₂ (θ ₂ <
θ ₀ ). The impedance control means 32a rotates the wheel support parts 13 and 23 based on the changed spring constant and the target rotation angle, and the support part motors 13m and 23m.
(S33), and the drive motors 13m and 23m for the supporting portions are driven based on the calculated driving forces (S33).
34) and the process returns to step S21. The driving force of the support portion motor 13m that rotates the wheel support portion 13 is calculated based on the following equation (9), and the driving force of the support portion motor 23m that rotates the wheel support portion 23 is as described above. (3)
It is calculated based on the formula.

K ₀ (θ-θ ₂ ) = F (9)

The wheels 11, 12, 21 provided on the carriage 1 are
The vehicle 22 travels on the upper side or the lower side of the stepped portion D, respectively, until the wheel next descending the stepped portion D starts to descend the stepped portion D.
The control device 32 causes the wheels 11, 12, 21, 22 to descend the step D based on the load received by the wheels 11, 12, 21, 22 from the road surface detected by the load sensors 14, 15, 24, 25. When it is judged again whether or not the load sensor 1 has started (S21), and it is judged that the stepped portion D has started to descend, each load sensor 1
Based on the loads detected by 4, 15, 24, and 25, it is determined which wheel has begun to descend the step D, and the wheel that needs to descend the step D is determined (S22). Here, the right front wheel 21 descends the step D.

The controller 32 controls the wheel motor 11 for rotating the left front wheel 11 and the left rear wheel 12 which do not descend the step D.
The driving force of m, 12m is increased by a predetermined amount, and
And the rotation speed of the left rear wheel 12 is increased by a predetermined speed (S2
3). In addition, the control device 32 can flexibly rotate the wheel support portion 23 according to the load received from the step portion D, in the spring constant in the impedance control performed on the wheel support portion 23 that supports the right front wheel 21 that descends the step portion D. The spring constant of the wheel support portion 13 is changed to the spring constant K ₁ of a magnitude to a spring constant K ₂ of a magnitude at which the wheel support portion 13 does not rotate with respect to the load received from the road surface (S24). Control device 32
Is determined by the impedance control means 32a from the spring constant in the impedance control process performed on the wheel support parts 13 and 23 changed as described above.
The driving forces of the support unit motors 13m and 23m that rotate the 23 are calculated based on the following equation (10) and the above equation (4) (S25), and each support portion is calculated based on the calculated driving force. Drive the motors 13m and 23m (S2
6).

K ₂ (θ-θ ₂ ) = F (10)

In the impedance control means 32a, the right front wheel 21 has a step portion D based on the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. If it is determined that the right front wheel 21 has completed the descent of the stepped portion D (S27), it is determined that all the wheels 11, 12,
It is determined whether the steps 21 and 22 have completed the descent of the step D (S28). Here, the front wheels 11 and 21 only have descended the stepped portion D, and the control device 32 in the truck 1 in which the front wheels 11 and 21 travel below the stepped portion D is
The rotation speeds of 1, 12, 21, 22 are changed to predetermined rotation speeds when traveling on a flat road surface (S29). Further, the control device 32 changes the spring constant in the impedance control performed on the wheel support portions 13 and 23 to the spring constant K ₀ when traveling on a flat road surface (S30).

Next, the controller 32 controls the support sensor 23.
s detects the current angle θ ₂ of the wheel support portion 23 due to the right front wheel 21 descending the step D (S31), and the target rotation angle in the impedance control performed on the wheel support portion 23 supporting the right front wheel 21. Is changed to the detected current angle θ ₂ (S32). Impedance control means 3
2a is based on the changed spring constant and target rotation angle, based on the above equation (9), the motors 13m and 23m for the respective support portions.
Are calculated respectively (S33), and the supporter motors 13m and 23m are driven based on the calculated driving forces (S34), and the process returns to step S21. In addition, trolley 1
Each of the wheels 11, 12, 21, 22 provided for the vehicle travels on the upper side or the lower side of the stepped portion D until the wheel next descending the stepped portion D starts to descend the stepped portion D.

The control device 32 includes load sensors 14, 15,
Based on the load received from the road surface by each wheel 11, 12, 21, 22 detected by 24, 25, each wheel 11, 12, 2
When it is determined again whether or not the first and the second 22 have started to descend the step D (S21), and it is determined that the step D has started to descend,
Based on the load detected by each load sensor 14, 15, 24, 25, it is determined which wheel has begun to descend the step D, and the wheel that needs to descend the step D is determined (S).
22). Here, the left rear wheel 12 descends the step D.
The control device 32 reduces the driving force of the wheel motors 21m and 22m that rotate the right front wheel 21 and the right rear wheel 22 that do not descend the step D by a predetermined amount to reduce the right front wheel 21 and the right rear wheel 2.
The rotation speed of 2 is reduced by a predetermined speed (S23).

Further, the control device 32 causes the wheel support portion 13 to flexibly adjust the spring constant in the impedance control performed on the wheel support portion 13 supporting the left rear wheel 12 descending the step portion D according to the load received from the step portion D. The spring constant of the wheel supporting portion 23 is changed to a spring constant K ₁ that allows the wheel supporting portion 23 to rotate to a spring constant K ₂ that does not allow the wheel supporting portion 23 to rotate with respect to the load received from the road surface (S24). . The control device 32 uses the wheel support parts 13 and 23 modified as described above.
From the spring constant in the impedance control process to
Each wheel support unit 1 is controlled by the impedance control unit 32a.
The driving forces of the supporter motors 13m and 23m for rotating the motors 3 and 23 are calculated based on the following equations (11) and (10), respectively (S25), and based on the calculated driving forces, respectively. Drive the support motors 13m and 23m (S
26).

K ₁ (θ-θ ₂ ) = F (11)

The impedance control means 32a is arranged such that the left rear wheel 12 has a stepped portion based on the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. It is determined whether or not the descent of D is completed (S27), and when it is determined that the left rear wheel 12 has completed the descent of the stepped portion D, all the wheels 11, 12,
It is determined whether the steps 21 and 22 have completed the descent of the step D (S28). Here, the front wheels 11 and 21 and the left rear wheel 1
The control device 32 in the trolley 1 in which the front wheels 11 and 21 and the left rear wheel 12 travel under the step D only when the vehicle 2 has just descended the step D, the rotation of the wheels 11, 12, 21, and 22. The speed is changed to a predetermined rotation speed when traveling on a flat road surface (S29). Further, the control device 32 sets the spring constant in the impedance control performed on the wheel support portions 13 and 23 to the spring constant K when traveling on a flat road surface.
_{The value} is changed to ₀ (S30).

Next, the controller 32 controls the support part sensor 13
By s, the current angle of the wheel support portion 13 due to the left rear wheel 12 descending the step D is detected (S31), and the target rotation angle in the impedance control performed on the wheel support portion 13 supporting the left rear wheel 12 is detected. Is changed to the detected current angle (S32). Here, the wheel support portion 13 is the rear wheel 1
When 2 moves below the step portion D, the wheel supporting portion 13 becomes horizontal, so that the target rotation angle of the wheel support portion 13 becomes the target rotation angle θ ₀ when traveling on a flat road surface in the horizontal direction. The impedance control unit 32a calculates the driving force of each of the support unit motors 13m and 23m from the changed spring constant and target rotation angle based on the above equations (3) and (9) (S33). The supporting unit motors 13m and 23m are driven based on the respective calculated driving forces (S34), and the process returns to step S21. In addition, each wheel 1 provided for the trolley 1
1, 12, 21, and 22 run on the upper side or the lower side of the step D, respectively, until the wheels that descend the step D next start to descend the step D.

The control device 32 includes the load sensors 14, 15,
Based on the load received from the road surface by each wheel 11, 12, 21, 22 detected by 24, 25, each wheel 11, 12, 2
When it is determined again whether or not the first and the second 22 have started to descend the step D (S21), and it is determined that the step D has started to descend,
Based on the load detected by each load sensor 14, 15, 24, 25, it is determined which wheel has begun to descend the step D, and the wheel that needs to descend the step D is determined (S).
22). Here, the right rear wheel 22 descends the step D.
The control device 32 reduces the driving force of the wheel motors 11m and 12m that rotate the left front wheel 11 and the left rear wheel 12 that do not descend the step D by a predetermined amount to reduce the left front wheel 11 and the left rear wheel 1.
The rotation speed of 2 is reduced by a predetermined speed (S23).

Further, the control device 32 causes the wheel supporting portion 23 to flexibly adjust the spring constant in the impedance control performed to the wheel supporting portion 23 supporting the right rear wheel 22 descending the step portion D according to the load received from the step portion D. The spring constant of the wheel supporting portion 13 is changed to a spring constant K ₁ of a size that allows the wheel supporting portion 13 to rotate to a spring constant K ₂ of a size that does not allow the wheel supporting portion 13 to rotate with respect to the load received from the road surface (S24). . The control device 32 uses the wheel support parts 13 and 23 modified as described above.
From the spring constant in the impedance control process to
Each wheel support unit 1 is controlled by the impedance control unit 32a.
The driving forces of the support unit motors 13m and 23m for rotating the motors 3 and 23 are calculated based on the above equations (5) and (11), respectively (S25), and each support unit is calculated based on the calculated driving force. The driving motors 13m and 23m are driven (S26).

In the impedance control means 32a, the right rear wheel 22 has a stepped portion based on the load received by the load sensors 14, 15, 24, 25 from the road surface by the load sensors 14, 15, 24, 25 at predetermined intervals. It is determined whether or not the descent of D has been completed (S27), and when it is determined that the right rear wheel 22 has completed the descent of the stepped portion D, all the wheels 11, 12,
It is determined whether or not the wheels 21 and 22 have completed the descent of the stepped portion D (S28), and when all the wheels 11, 12, 21, 22 descend the stepped portion D, the descent process of the stepped portion D is ended. .

As described above, when the front wheels descend the stepped portion D, the rotation speed of each wheel supported by the wheel supporting portion other than the wheel supporting portion supporting the front wheels is lowered by the stepped portion D. By controlling each wheel motor so as to be faster than the rotation speed of the front wheel and the wheel supported by the same wheel support portion as the front wheel, the front wheel that descends the step D is
It is possible to descend along the step portion D without giving a large impact to the road surface and without floating. Further, when the rear wheel descends the step D, the rotation speed of each wheel supported by the wheel support portion other than the wheel support portion supporting the rear wheel is set to the rear wheel descending the step D By controlling each wheel motor so as to be slower than the rotation speed of the wheel supported by the same wheel support portion as the rear wheel,
The front wheel descending along the step D can descend along the step D without giving a large impact on the road surface and without floating.

Further, by setting the spring constant in the impedance control processing performed on the wheel supporting portion that supports the wheel that does not descend the step portion D so that the wheel supporting portion does not rotate with respect to the load received from the step portion D, The wheel that descends the stepped portion D can more easily rotate the wheel support portion that supports itself. Therefore, the wheel can more easily move downward along the step D, and the step D can be lowered. Even when traveling on a road surface having grooves, each wheel can travel corresponding to each groove.

In the above-described embodiment, it is detected that each wheel approaches the front step portion based on the load detected by each load sensor, and the rotation speed of each wheel is changed to a predetermined speed. However, an infrared sensor or the like is provided, the size of a step to be moved up and down is detected in advance, and the rotation speed of each wheel 11, 12, 21, 22 is changed based on the detected step, and An infrared sensor may be used to detect the completion of the elevation of the step. In addition, two infrared sensors are set as one set, and the wheels 11, 12, 2 are respectively set.
By arranging above the vehicle 1 and 22, it is possible to calculate the approach angle of the trolley 1 to the stepped portion, and it is determined whether or not the stepped portion can be moved up and down based on the calculated approach angle. It may be configured.

Further, in the above-described embodiment, when the step portion is moved up and down, the wheel support portion that supports the wheels that do not move up and down the step portion is controlled so as not to rotate to support the carriage body 30. By rotating the wheel supporting portion that supports the wheel that raises and lowers the step portion in a direction opposite to the rotation direction, and supporting the center of gravity of the carriage main body 30 by the three wheels that do not raise and lower the step portion, The wheels that move up and down can move more smoothly in the vertical direction. Also, each wheel 1
The axles of the wheels 1, 12, 21, 22 are arranged at appropriate intervals from the wheel support portions 13, 23 that support the wheels, whereby the left and right wheels 11, 12, 21, 22, 22 are arranged.
It is possible to more easily rotate the wheel support portions 13 and 23 due to the difference in rotation speed of the wheels 11, 12, and 2.
Although the wheels 1 and 22 can be moved in the vertical direction more easily, the axles of the wheels 11, 12, 21 and 22 may be arranged on the same straight line as the wheel support portions 13 and 23.

[0087]

According to the first aspect of the invention, the wheel supports that are long in the front-rear direction and that rotate up and down about the midpoint of the front-rear direction are arranged on the left and right, and the wheels supported by one wheel support rotate. By providing the speed control means for controlling the speed to be faster or slower than the rotation speed of the wheel supported by the other wheel support, the rotation speed of each wheel supported by the left and right wheel supports is different, and this difference As a result, the trolley body is twisted. It is possible to realize a trolley in which each wheel support is rotated by the twist of the trolley body, and the wheels supported by the wheel support can be appropriately moved in the vertical direction by the rotation of the wheel support. .

In the case of the second invention, the speed control means is provided with a judging means for detecting an external force received by each wheel and judging whether the detected external force is larger or smaller than a predetermined range. Based on the result determined by the determination means, the rotation speed of the wheel that receives the external force and the wheel supported by the same wheel support as the wheel is faster or slower than the rotation speed of the wheel supported by another wheel support. By being configured to control, the rotation speed of each wheel supported by the left and right wheel supports varies depending on the external force received by each wheel,
Due to this difference, the carriage main body is twisted, and the twisting of the carriage main body causes each wheel support body to rotate, and the wheels supported by the wheel support body can appropriately move in the vertical direction.

Therefore, even when traveling on a road surface having irregularities, grooves, etc., each wheel does not exert a large impact on the road surface and each wheel on the road surface does not float. It is possible to realize a truck that flexibly travels in response to unevenness and grooves. Further, each wheel is traveling on a flat road surface while receiving an external force in a predetermined range, and whether the external force received by each wheel detected by the external force detecting means is larger or smaller than the predetermined range. By providing the determination means for determining, it is possible to detect that the wheel that has received the external force has collided with the step portion to the upper front when the determination means determines that it is larger than the predetermined range. If the determination means determines that the wheel size is smaller than the predetermined range, it can be detected that the wheel receiving the external force has started to descend the front step portion.

In the case of the third invention, a desired wheel support can be rotated more easily by further providing a structure for controlling the other wheel support in the first or second invention so as not to rotate. The desired wheel supported by the wheel support can move in the vertical direction more easily, and even when traveling on a road surface having unevenness and grooves, each unevenness on the road surface Also, it is possible to realize a cart that travels flexibly in the groove.

According to the fourth aspect of the invention, the level difference detecting means for detecting the level difference is provided, and the rotation speed of each wheel is controlled based on the level difference detected by the level difference detecting means. Each wheel support is rotated by an appropriate angle in accordance with the twist of the bogie main body caused by the difference in the rotational speeds of the left and right wheels, which is controlled according to the degree of the wheel support, and the rotation of the wheel support causes the wheel support to rotate. The wheels supported by can move up and down by an appropriate distance. Therefore, even when traveling on a road surface having a stepped portion including a groove or the like, a large impact is exerted on the road surface by moving each wheel in the vertical direction by an appropriate distance according to the step detected in advance. It is possible to realize a dolly that travels flexibly corresponding to each step on the road surface without exerting any influence and without causing the wheels to float.

In the case of the fifth invention, the axle of each wheel is
By arranging the wheel supporter that supports the wheel at an appropriate interval, the wheel supporter can be more easily rotated due to the difference in the rotational speeds of the left and right wheels, and the wheel is It is possible to realize a cart that can move in the vertical direction more easily.

[Brief description of drawings]

FIG. 1 is a perspective view showing a carriage according to the present invention.

FIG. 2 is a front view showing a carriage according to the present invention.

FIG. 3 is a side view showing a truck according to the present invention.

FIG. 4 is an explanatory diagram showing a rotation mode of a wheel support portion included in the truck according to the present invention.

FIG. 5 is a block diagram showing a configuration of a truck according to the present invention.

FIG. 6 is a flowchart showing a step-over procedure of a stepped portion by a trolley according to the present invention.

FIG. 7 is a flowchart showing a step-over procedure of a stepped portion by a trolley according to the present invention.

FIG. 8 is an explanatory diagram for explaining a process of getting over a step portion by a trolley according to the present invention.

FIG. 9 is a flow chart showing a procedure for lowering a stepped portion by a trolley according to the present invention.

FIG. 10 is a flow chart showing a procedure for lowering a stepped portion by a trolley according to the present invention.

FIG. 11 is an explanatory diagram for explaining a step of lowering a stepped portion by a trolley according to the present invention.

[Explanation of symbols]

1 dolly 10, 20 legs 11,12,21,22 wheels 13,23 Wheel support 14, 15, 24, 25 Load sensor 13m, 23m support motor 32 control device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Seiji Murakami             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F term (reference) 3D050 BB01 DD01 DD07 EE08 EE15                       FF04 GG01 JJ09 KK06 KK14                 5H301 AA01 AA10 GG06 GG23 GG28                       GG29 HH10 LL01 LL11

Claims (5)

[Claims] 1. A trolley in which wheel supports that are long in the front-rear direction and rotate up and down about a midway portion in the front-rear direction are arranged on the left and right sides, and wheels are provided in the front and rear parts of the wheel support, respectively.
A trolley comprising speed control means for controlling the rotational speed of a wheel supported by one wheel support to be faster or slower than the rotational speed of a wheel supported by the other wheel support. 2. An external force detecting means for detecting an external force received by each of the wheels, and a determining means for determining whether the external force detected by the external force detecting means is larger or smaller than a predetermined range, The speed control means, based on the determination result determined by the determination means, determines the rotational speed of the wheel that receives the external force and the wheel that is supported by the same wheel support as the wheel of the wheel that is supported by another wheel support. The trolley according to claim 1, wherein the trolley is controlled to be faster or slower than the rotation speed. 3. The rotation control means for controlling the other wheel support not to rotate when the judgment means judges that the judgment result is larger or smaller than the predetermined range. The trolley described in 1 or 2. 4. A step detecting means for detecting a step is provided, and the speed control means is configured to control the rotational speed of each of the wheels based on the step detected by the step detecting means. The dolly according to any one of claims 1 to 3. 5. The trolley according to claim 1, wherein an axle of the wheel is arranged at a proper distance from the wheel support that supports the wheel.