JP2009101897A - Inverted wheel type moving body and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverted wheel type moving body improved in safety, and to provide a control method thereof. <P>SOLUTION: This inverted wheel type moving body includes motors 34 and 36 for driving a right driving wheel 18 and a left driving wheel 20 to rotate, a driver seat 74 turnably supported by mounts 26 and 28 through swing arms 17 and 19, and a slide mechanism 68 for driving the driver seat 74. A control section 80 detects the weight of a car body 77 based on the driving force of the motors 34 and 36 or the slide mechanism 68. When the weight of the car body exceeds a threshold value or when the weight of the car body reaches an end of a drive range of the slide mechanism 68, the car body is lowered. When the driving force of the slide mechanism does not exceed a threshold value and while the slide mechanism 68 does not reach a slide end, the control section controls to move the car body, being inverted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inverted wheel type moving body and a control method thereof.

An inverted wheel type moving body such as an inverted two-wheeled vehicle is normally controlled to move while correcting the center of gravity so as to maintain the stable state by driving the left and right drive wheels. Furthermore, in order to stabilize an inverted state, the structure which drives the inertial body provided above the wheel is disclosed (patent document 1). In this inverted wheel type moving body, the inertial body is slid and moved during traveling. Thereby, since a gravity center position moves rapidly on the vertical line of an axle, inversion can be stabilized. Furthermore, the inverted wheel type moving body may be provided with auxiliary wheels for preventing the fall.
JP 2006-205839 A

  A vehicle or a passenger is placed on such an inverted wheel type moving body. And a wheel is driven in order to stabilize inversion in the state in which a passenger etc. are riding. However, the inverted wheel type moving body has a limit in the weight of the passenger or the vehicle and the size of the displacement of the center of gravity. If the inverted operation is performed in a state where the limit value is exceeded, there is a risk of falling (failing) or running away (grounding of the auxiliary wheel). In other words, if it is attempted to invert the weight or moment limit value, a command exceeding the specifications of the drive motor will be output. Further, if the inversion control is continued even though the displacement of the center of gravity is larger than the limit value, the mechanical balance is poor and the auxiliary wheel collides with the ground. Therefore, if the weight or the center-of-gravity position deviation exceeds the limit value, there is a risk of falling or running away. A sensor for detecting the weight can be provided, but this leads to an increase in electrical wiring and an increase in cost. In addition, the weight may not be detected accurately depending on the state of the passenger or the vehicle. As described above, the conventional inverted wheel type moving body has a problem that the inversion operation cannot be performed safely.

  The present invention has been made to solve such a problem, and an object thereof is to provide an inverted wheel type moving body that can safely perform an inverted operation, and a control method thereof.

  An inverted wheel type moving body according to a first aspect of the present invention includes a chassis that rotatably supports a wheel, a first drive unit that rotationally drives the wheel, and a rotating member that rotates with respect to the chassis via a support member. A movably supported vehicle body part, a second drive part for driving the vehicle body part, a third drive part for changing the height of the vehicle body part, the first drive part, and the second drive part An inverted wheel type moving body comprising: a drive unit; and a control unit that controls a third drive unit, wherein the control unit has a threshold value for the driving force of the first or second drive unit. When it exceeds or reaches the end of the drive range of the second drive unit, the third drive unit is controlled to lower the vehicle body unit, and the first or second drive unit When the driving force does not exceed the threshold value and the second driving unit has not reached the end of the driving range, the inverted vehicle Type mobile so as to move while inverted, and controls the first and second driving portions. As a result, when the weight or moment exceeds the limit value, the vehicle height decreases. Therefore, since the inverted wheel type moving body can be prevented from overturning, safety can be improved.

  An inverted wheel type moving body according to a second aspect of the present invention is the above-described inverted wheel type moving body, wherein the inclination angular velocity of the posture of the inverted wheel type moving body does not change or exceeds a threshold value. In this state, when the vehicle reaches the end of the drive range, the control unit controls the third drive unit to lower the vehicle body unit. Thereby, it can be determined whether it can be inverted easily and reliably, and safety can be improved.

  An inverted wheel type moving body according to a third aspect of the present invention is the above inverted wheel type moving body, wherein the second drive unit has a slide mechanism that slides the vehicle body part back and forth. When the sliding force of the second drive unit does not exceed a threshold value, the control unit controls the vehicle body unit to be lowered. Thereby, since it is determined whether a weight can be inverted easily, the number of parts can be reduced.

  An inverted wheel type moving body according to a fourth aspect of the present invention is the above inverted wheel type moving body, further comprising auxiliary wheels that move up and down when the third drive unit is driven, When the driving force of one or the second driving unit exceeds a threshold value, or when the driving force reaches the end of the driving range of the second driving unit, the control unit controls the third driving unit. The auxiliary wheel is grounded. As a result, the mobile body can be prevented from falling and running away, and safety can be improved.

  According to a fifth aspect of the present invention, there is provided a method of controlling an inverted wheel type moving body comprising: a chassis that rotatably supports a wheel; a first drive unit that rotationally drives the wheel; A vehicle body portion rotatably supported by the vehicle body; a second drive unit that drives the vehicle body portion; an auxiliary wheel that is provided apart from the wheel; And a third driving unit that switches between the separated state and an inverted wheel type moving body, wherein when the driving force of the first or second driving unit exceeds a threshold value, Or the step of controlling the third drive unit to lower the vehicle body part when reaching the end of the drive range of the second drive unit, and the driving force of the first or second drive unit Does not exceed the threshold value and does not reach the end of the driving range of the second driving unit. To the to move while inverted to inverted wheel type moving body, and has a step of controlling the first and second driving portions. As a result, when the weight or moment exceeds the limit value, the vehicle height decreases. Therefore, since the inverted wheel type moving body can be prevented from overturning, safety can be improved.

  The control method of the inverted wheel type moving body according to the sixth aspect of the present invention is the above control method, wherein the tilt angular velocity of the posture of the inverted wheel type moving body does not change or exceeds a threshold value. In this state, when the vehicle reaches the end of the drive range, the control unit controls the third drive unit to lower the vehicle body unit. Thereby, it can be determined whether it can be inverted easily and reliably, and safety can be improved.

  The inverted wheel type mobile body control method according to the seventh aspect of the present invention is the control method described above, wherein the second drive unit includes a slide mechanism that slides the vehicle body part back and forth. The vehicle body is lowered when the sliding force of the sliding mechanism does not exceed a threshold value. Thereby, since it can be determined whether it can invert easily, a number of parts can be reduced.

  An inverted wheel type moving body control method according to an eighth aspect of the present invention is the above-described control method, further comprising an auxiliary wheel that moves up and down when the third driving unit is driven, The auxiliary wheel is grounded when the driving force of one or the second driving unit exceeds a threshold value or reaches the end of the driving range of the second driving unit. As a result, the mobile body can be prevented from falling and running away, and safety can be improved.

  An object of the present invention is to provide an inverted wheel type moving body that can safely perform an inverted operation, and a control method thereof.

  The moving body according to the present embodiment is an inverted wheel type moving body that moves by the inverted pendulum control. The moving body moves to a predetermined position by driving a wheel grounded on the ground. Furthermore, the inverted state can be maintained by driving the wheel according to the output from the gyro sensor or the like. Further, the moving body moves according to the operation amount operated by the operator while maintaining the inverted state.

  The configuration of the moving body 100 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view schematically showing the configuration of the moving body 100, and FIG. 2 is a front view schematically showing the configuration of the moving body 100.

  As shown in FIG. 2, the moving body 100 is an inverted wheel type moving body (running body), and includes a right driving wheel 18, a left driving wheel 20, a right swing arm 17, a left swing arm 19, A vehicle body 12. The vehicle body 12 is a part of the upper body portion of the moving body 100 disposed above the right drive wheel 18 and the left drive wheel 20. Here, the traveling direction of the moving body 100 (perpendicular to the paper surface of FIG. 2) is defined as the front-rear direction, and the direction perpendicular to the front-rear direction on the horizontal plane is defined as the left-right direction (lateral direction). Therefore, FIG. 2 is a view of the moving body 100 viewed from the front side in the traveling direction, and FIG. 1 is a view of the moving body 100 viewed from the left side.

  During traveling, the right swing arm 17 and the left swing arm 19 adjust the vehicle height. Furthermore, one or both swing arms are driven to adjust the left and right inclination angles of the vehicle body 12 with respect to the ground. For example, it is assumed that only the right drive wheel 18 rides on a step while traveling on a horizontal ground, or the ground changes to an upwardly inclined surface. In this case, the right drive wheel 18 is higher than the left drive wheel 20. For this reason, the joint of the right swing arm 17 is driven so that the right driving wheel 18 is brought closer to the direction of the vehicle body 12. As a result, the height of the right drive wheel 18 can be absorbed, and the vehicle body 12 can be leveled in the lateral direction (left-right direction).

  A right mount 26 is fixed to the right swing arm 17 side end side, and the right drive wheel 18 is rotatably supported via an axle 30. The right drive wheel 18 is fixed to the rotation shaft C <b> 1 of the right wheel drive motor 34 via the axle 30. The right wheel drive motor 34 is fixed in the right mount 26 and functions as a wheel drive unit (actuator).

  A left mount 28 is fixed to the side end side of the left swing arm 19 and supports the left driving wheel 20 via an axle 32 so as to be rotatable. The left drive wheel 20 is fixed to the rotation shaft C <b> 2 of the left wheel drive motor 36 via the axle 32. The left wheel drive motor 36 is fixed in the left mount 28 and functions as a wheel drive unit (actuator). The right driving wheel 18 and the left driving wheel 20 are a pair of wheels that are in contact with the ground and rotate substantially coaxially. As the right driving wheel 18 and the left driving wheel 20 rotate, the moving body 100 moves. Further, the right wheel drive motor 34 and the left wheel drive motor 36 serve as drive wheel motors for driving the wheels. The right mount 26 and the left mount 28 serve as a chassis that rotatably supports the left and right drive wheels.

  The right wheel drive motor 34 and the left wheel drive motor 36 (hereinafter also referred to as motors 34 and 36) are, for example, servo motors. The wheel actuator is not limited to an electric motor, and may be an actuator using pneumatic pressure or hydraulic pressure. In the following description, the right driving wheel 18 and the left driving wheel 20 may be collectively referred to as driving wheels.

  The right mount 26 includes a right wheel encoder 52. The right wheel encoder 52 detects a rotation angle as a rotation amount of the right drive wheel 18. The left mount 28 includes a left wheel encoder 54. The left wheel encoder 54 detects a rotation angle as a rotation amount of the left drive wheel 20.

  The right swing arm 17 includes an upper right link 21, a right swing shaft 62, and a right swing arm drive motor 60. The left swing arm 19 includes an upper left link 22, a left swing shaft 66, and a left swing arm drive motor 64. An upper right link 21 and an upper left link 22 are fixed to the lower portion of the vehicle body 12. A right swing arm drive motor 60 is fixed to the upper right link 21 and drives the right swing arm 17 around the rotation axis C4 via the right swing shaft 62. A left swing arm drive motor 64 is fixed to the left swing shaft 66, and drives the left swing arm 19 around the rotation axis C5 via the left swing shaft 66. Thus, the right swing arm 17 is provided with a rotary joint that rotates about the rotation axis C4, and the left swing arm 19 is provided with a rotary joint that rotates about the rotation axis C5. The joints provided on the right swing arm 17 and the left swing arm 19 (hereinafter also referred to as swing arms 17 and 19) are referred to as swing arm joints.

  A passenger seat drive motor 70, a rack and pinion 72, a gyro sensor 48, and a passenger seat 74 are attached to the vehicle body 12. Further, an upper right link 21 and an upper left link 22 are attached to the vehicle body 12 so as to face each other.

  A rack and pinion 72 is provided near the center of the vehicle body 12. The rack of the rack and pinion is provided along the front-rear direction. The boarding seat 74 is supported by the rack and pinion 72. That is, the boarding seat 74 is attached to the vehicle body 12 via the rack and pinion 72. The passenger seat 74 has a shape of a chair on which a passenger can sit. Instead of the rack and pinion 72, it may be slid using a ball screw or the like.

  A passenger seat drive motor 70 is fixed to the upper portion of the vehicle body 12. The passenger seat 74 and the passenger seat drive motor 70 are connected by a rack and pinion 72. The passenger seat drive motor 70 rotates about the rotation axis C3. Thereby, a rotational force is applied to the pinion of the rack and pinion 72. The rotational motion of the passenger seat drive motor 70 is converted into a linear motion by the rack and pinion 72. That is, when the passenger seat drive motor 70 is driven, the position of the passenger seat 74 with respect to the vehicle body 12 slides back and forth. At this time, the position of the center of gravity of the passenger seat 74 and the occupant or the vehicle changes forward and backward with respect to the vehicle body 12. As a means for changing the position of the center of gravity of the passenger seat 74 and the occupant or the vehicle with respect to the vehicle body 12, in addition to the slide mechanism, a rotating shaft mechanism, a turning mechanism, or the like can be realized. . Further, the power of the passenger seat drive motor 70 may be transmitted to the passenger seat 74 via a gear, a belt, a pulley, or the like. Here, the entire structure that moves back and forth by the passenger seat drive motor 70 is referred to as a vehicle body portion 77. The vehicle body portion 77 includes a boarding seat 74, an operation module 46, and the like. Of course, when an actuator for driving the vehicle body 12 is provided, the vehicle body 12 is also included in the vehicle body portion 77. The passenger seat drive motor 70 is provided with an encoder (not shown) for measuring the slide position.

  The rotation axis C3 is parallel to the rotation axes C1 and C2, and is located above the rotation axes C1 and C2. A right swing arm 17 is provided between the rotation axis C3 and the rotation axis C1, and a left swing arm 19 is provided between the rotation axis C3 and the rotation axis C2. The right swing arm drive motor 60 rotates the right swing arm 17 around the rotation axis C4, and the left swing arm drive motor 64 rotates the left swing arm 19 around the rotation axis C5. During normal travel, the rotation axis C1 to the rotation axis C5 are horizontal.

  Furthermore, the moving body 100 is provided with two auxiliary wheels 51 in order to prevent the mobile body 100 from falling. The auxiliary wheel 51 is rotatably supported with respect to the auxiliary wheel support block 55. The auxiliary wheel support block 55 is attached to the vehicle body 12. Here, one auxiliary wheel 51 is disposed on the front side of the driving wheel, and the other auxiliary wheel 51 is disposed on the rear side of the driving wheel. The auxiliary wheel 51 is a driven wheel and rotates as the moving body 100 moves.

  When starting normal travel, the auxiliary wheel 51 is released by extending the swing arm joint. That is, the swing arm joint is moved so that the vehicle body 12 moves upward, and the auxiliary wheel 51 is moved upward. In the stop state, the auxiliary wheel 51 is grounded by contracting the swing arm joint. That is, by bending the swing arm joint, the vehicle body 12 approaches the ground, and the auxiliary wheel 51 moves downward. In this way, by moving the auxiliary wheel 51 up and down, it is possible to switch between a grounded state in which the auxiliary wheel 51 is grounded and a grounded state in which the vehicle is separated and travels on two wheels. In this way, the moving body 100 shifts from the grounded state of the four wheels to the ground-off state of the two-wheel state using the swing arm when standing up.

  The rotation axis of one auxiliary wheel 51 is located on the front side above the rotation axes C1 and C2, and the rotation axis of the other auxiliary wheel 51 is located on the rear side above the rotation axes C1 and C2. That is, one of the auxiliary wheels 51 is disposed in front of the axle of the driving wheel, and the other is disposed in the rear of the axle of the driving wheel. Thereby, it can prevent that the mobile body 100 falls forward and backward. In addition, you may prevent a fall by the fall prevention member other than an auxiliary wheel. For example, the fall can be prevented by a stopper or the like protruding in the front-rear direction.

  A battery module 44 and a sensor 58 are housed in the vehicle body 12. The sensor 58 is an optical obstacle detection sensor, for example, and outputs a detection signal when an obstacle is detected in front of the moving body 100. The sensor 58 may be a sensor other than the obstacle sensor. For example, an acceleration sensor can be used as the sensor 58. Of course, two or more sensors may be used as the sensor 58. The sensor 58 detects a change amount that changes in accordance with the state of the moving body 100. The battery module 44 has a sensor 58, a gyro sensor 48, a right wheel drive motor 34, a left wheel drive motor 36, a right swing arm drive motor 60, a left swing arm drive motor 64, a passenger seat drive motor 70, a control unit 80, and the like. Supply power.

  A gyro sensor 48 is provided on the vehicle body 12. The gyro sensor 48 detects an angular velocity with respect to the inclination angle of the vehicle body 12. Here, the inclination angle of the vehicle body 12 is a degree of inclination from the axis at which the center of gravity of the moving body 100 extends vertically above the axles 30 and 32. For example, the vehicle body 12 is inclined forward in the traveling direction of the moving body 100. The case is represented as “positive”, and the case where the vehicle body 12 is inclined rearward in the traveling direction of the moving body 100 is represented as “negative”. Therefore, when the vehicle body 12 is horizontal, the tilt angle is 0 °. During normal traveling, the control target value of the tilt angle is 0 °. Feedback control is performed so as to follow the control target value. Further, the inclination angle in the front-rear direction is set as the inclination angle of the posture of the moving body 100.

  In addition to the front-rear direction of the traveling direction, the tilt angular velocity in the left-right direction is measured using a three-axis gyro sensor 48 of roll, pitch, and yaw. Thus, the gyro sensor 48 measures the change in the tilt angle of the vehicle body 12 as the tilt angular velocity of the vehicle body 12. Of course, the gyro sensor 48 may be attached to another location. The tilt angular velocity measured by the gyro sensor 48 changes according to the change in the posture of the moving body 100. That is, the inclination angular velocity is a change amount that changes according to the position of the center of gravity of the vehicle body 12 with respect to the position of the axle. Therefore, when the inclination angle of the posture changes suddenly due to disturbance or the like, the value of the inclination angular velocity increases.

  An operation module 46 is provided on the side surface of the boarding seat 74. The operation module 46 is provided with an operation lever (not shown) and a brake lever (not shown). The operating lever is an operating member for the passenger to adjust the traveling speed and traveling direction of the moving body 100. The passenger adjusts the moving speed of the moving body 100 by adjusting the operation amount of the operating lever. Can do. Moreover, the passenger can specify the moving direction of the moving body 100 by adjusting the operating direction of the operating lever. The moving body 100 can make forward, stop, reverse, left turn, right turn, left turn, and right turn according to the operation applied to the operation lever. The moving body 100 can be braked when the passenger tilts the brake lever. The traveling direction of the moving body 100 is a direction perpendicular to the axles 30 and 32 in the horizontal plane. The operation module 46 is provided with a switch for switching the control mode.

  Further, a control unit 80 is mounted on the backrest portion of the boarding seat 74. The control unit 80 controls the right wheel drive motor 34 and the left wheel drive motor 36 in accordance with the operation performed by the occupant on the operation module 46, and controls the travel (movement) of the moving body 100. The control unit 80 controls the right wheel drive motor 34 and the left wheel drive motor 36 in accordance with an operation on the operation module. As a result, the right wheel drive motor 34 and the left wheel drive motor 36 are driven with the acceleration and speed command values according to the operation of the operation module 46.

  The control unit 80 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a communication interface, and the like, and controls various operations of the mobile unit 100. And this control part 80 performs various control according to the control program stored, for example in ROM. The control unit 80 performs robust control, state feedback control, PID control, or the like so as to achieve a desired acceleration and target speed according to an operation in the operation module 46, and so that the moving body 100 is maintained upside down. The right wheel drive motor 34 and the left wheel drive motor 36 are controlled by the known feedback control. As a result, the moving body 100 travels while accelerating / decelerating in accordance with the operation of the operation module 46.

  That is, the operation module 46 acquires the operation amount given by the passenger's operation, and outputs this operation amount to the control unit 80 as an operation signal. Then, the control unit 80 calculates a target acceleration and a target speed of the moving body 100 based on the operation signal, and feedback-controls the moving body 100 so as to follow the target acceleration and target speed. Thereby, the moving body 100 can be moved while being inverted.

  Further, the control unit 80 controls the right wheel drive motor 34, the left wheel drive motor 36, the right swing arm drive motor 60, the left swing arm drive motor 64, and the passenger seat drive motor 70. Here, the control unit 80 performs control so that the passenger seat drive motor 70 operates in cooperation with the right wheel drive motor 34 and the left wheel drive motor 36. That is, the driving wheel is rotated and the boarding seat 74 is slid so as to stabilize the inversion. Thereby, the inclination angle of the vehicle body 12 becomes small, and the inversion can be stabilized. In this manner, the passenger seat drive motor 70 operates in cooperation with the right swing arm drive motor 60, the left swing arm drive motor 64, and the passenger seat drive motor 70.

  Next, the configuration of the control unit 80 that performs the above control will be described with reference to FIG. FIG. 3 is a block diagram illustrating a configuration of a control system including the control unit 80. As shown in FIG. 3, the control unit 80 includes a swing arm control unit 81 and a drive wheel / slide cooperative control unit 82. Sensors 83 indicate various sensors provided in the moving body 100, and include, for example, a gyro sensor 48, a right wheel encoder 52, a left wheel encoder 54, a sensor 58, and the like. And the control part 80 performs an inversion control calculation, and calculates a control target value. Then, a deviation between the control target value and the current value is obtained. The current value can be calculated based on the output from the sensors 83, for example. Then, feedback control is performed by multiplying the deviation by a predetermined feedback gain.

  In addition, the moving body 100 is provided with an amplifier that drives and controls each motor. Here, the amplifiers provided in the right wheel drive motor 34, the left wheel drive motor 36, the right swing arm drive motor 60, the left swing arm drive motor 64, and the passenger seat drive motor 70 are an amplifier 34a, an amplifier 36a, and an amplifier 60a, respectively. , Amplifier 64a and amplifier 70a. Each amplifier operates based on a control signal from the control unit 80. The control unit 80 outputs a control signal corresponding to the slide speed, slide position, and slide force to the amplifier 70 a of the passenger seat drive motor 70. Further, a control signal corresponding to the wheel torque is output to the amplifiers 34a and 36a of the motors 34 and 36.

  The swing arm control unit 81 controls the right swing arm drive motor 60 and the left swing arm drive motor 64. For example, the swing arm control unit 81 outputs a control signal to drive the swing arm joint 67 so that the swing arm expands and contracts. Thereby, it is possible to switch between a grounded state where the auxiliary wheel 51 is grounded and a grounded state where the auxiliary wheel 51 is grounded. When traveling on an inclined surface, a control signal is output based on the output of the gyro sensor 48 or the like. Thereby, the angle of the inclined surface is absorbed and the vehicle body 12 becomes horizontal. A control signal from the swing arm control unit 81 is input to the right swing arm drive motor 60 and the left swing arm drive motor 64 via the amplifiers 60a and 64a, and the right swing arm drive motor 60 and the left swing arm drive motor 64 To drive. An encoder that detects the rotation angle of the swing arm joint may be provided to perform feedback control. That is, feedback control can be performed according to the joint angle and joint angular velocity of the swing arm joint 67.

  The drive wheel / slide cooperative control unit 82 controls the right wheel drive motor 34, the left wheel drive motor 36, and the passenger seat drive motor 70 in a coordinated manner. That is, the drive wheel / slide cooperative control unit 82 calculates control target values for the right wheel drive motor 34, the left wheel drive motor 36, and the passenger seat drive motor 70. For example, the posture inclination angle, the posture inclination angular velocity, the rotation speed of the driving wheel, and the sliding speed of the passenger seat 74 are calculated as control target values. Then, feedback control is performed so as to follow the control target value. Specifically, the drive torque for each motor is output as a command value. The inclination angular velocity of the vehicle body 12 is measured by the gyro sensor 48. Then, the inclination angle of the vehicle body 12 is obtained by integrating the inclination angular velocity. For example, during inverted traveling, feedback control is performed so that the target inclination angle of the posture becomes 0 °. When stopping on the spot, feedback control is performed so that the target inclination angular velocity becomes zero.

  Further, the rotational speed of the drive wheel 78 can be obtained from the outputs of the right wheel encoder 52 and the left wheel encoder 54. The slide speed of the slide mechanism 68 can be obtained from the output of an encoder provided in the passenger seat drive motor 70. The slide mechanism 68 can be obtained from the rotational torque of the passenger seat drive motor 70. Then, feedback control is performed by applying an appropriate feedback gain to the deviation between the control target value and the current value. Of course, the cooperative control of the right wheel drive motor 34, the left wheel drive motor 36, and the passenger seat drive motor 70 by the drive wheel / slide cooperative control unit 82 is not limited to the above control.

  Further, when the weight or moment exceeds the limit value, the control unit 80 places the auxiliary wheel in a grounded state. That is, if the weight or moment exceeds a preset threshold value, it is determined that the limit value is exceeded, and the swing arm joint 67 is driven. As a result, the vehicle body 12 is lowered and the auxiliary wheel 51 is grounded. The mobile body 100 can be prevented from falling or running away, and safety can be improved.

  Next, control when the auxiliary wheel 51 of the moving body 100 moves from the landing state to the takeoff state will be described with reference to FIG. 4A to 4D are side views schematically showing the operation of the moving body 100. In FIG. 4, the right driving wheel 18 and the left driving wheel 20 are shown as driving wheels 78. In FIG. 4, a mechanism for sliding the vehicle body 77 is shown as a slide mechanism 68, and a rotary joint provided on the swing arm is shown as a swing arm joint 67. Therefore, by driving the slide mechanism 68 including the passenger seat drive motor 70 and the rack and pinion 72, the vehicle body portion 77 slides back and forth with respect to the vehicle body 12. Furthermore, the vehicle body portion 77 and the vehicle body 12 are combined to form an upper body portion 76. Therefore, the entire configuration supported by the swing arm is the upper body portion 76.

  First, in order to shift from the grounding state (four-wheel grounding) to the ground-off state (two-wheel grounding), the swing arm joint 67 is driven as shown in FIG. That is, the swing arm is extended by rotating the right swing arm drive motor 60 and the left swing arm drive motor 64. As a result, the vehicle body 12 moves away from the ground, and the auxiliary wheel 51 attached to the vehicle body 12 moves upward via the auxiliary wheel support block 55. At this time, the gravity center position of the upper body portion 76 (the combined gravity center position of the vehicle body portion 77 and the vehicle body 12) is shifted forward from the vertical line of the axle, and the movable body 100 assumes a forward leaning posture. For this reason, first, the auxiliary wheel 51 on the rear side is released, and then the auxiliary wheel 51 on the front side is released.

  Then, as shown in FIG. 4B, the slide mechanism 68 slides to return the posture. In FIG. 4B, the rear side auxiliary wheel 51 is separated from the ground and the front side auxiliary wheel 51 is grounded. Since the moving body 100 is in the forward leaning posture, the vehicle body portion 77 slides backward. That is, the slide mechanism 68 is controlled so that the position of the center of gravity of the upper body portion 76 approaches the vertical line of the axle. At this timing, the drive wheel 78 has not yet been driven to rotate.

  At this time, the weight of the vehicle body 77 is detected by measuring the sliding force F that moves the sliding mechanism 68. Then, it is determined whether or not the weight of the vehicle body portion 77 exceeds a preset threshold value (limit value). Specifically, the weight of the vehicle body portion 77 can be obtained from the slide force F by obtaining the relationship between the slide force F and the weight of the vehicle body portion 77 in advance. The sliding force F can be obtained from the torque value of the passenger seat drive motor 70.

  When the sliding force F exceeds the threshold value, it is determined that the weight is over and the grounding state is restored. That is, the swing arm joint 67 is contracted to bring the vehicle body 12 closer to the ground. Thereby, as shown in FIG.4 (c), the auxiliary wheel 51 moves below. Then, the moving body 100 returns to the ground state. Thus, when the sliding force F exceeds the threshold value, it is determined that the weight is over. Then, the transition from the grounded state to the ground-off state is stopped, and the grounded state is restored.

  When the sliding force F is less than the threshold value, it is determined that the weight is not over and the driving of the sliding mechanism 68 is continued. At this time, the moving body 100 is in a forward tilt posture. For this reason, the slide mechanism 68 is further driven rearward so as to stabilize the inversion. Here, it is determined whether or not the inclination changes before the slide mechanism 68 reaches the slide end. Specifically, first, it is checked whether the inclination angular velocity of the posture exceeds a threshold value (specified value). When the tilt angular velocity exceeds the threshold value, the posture changes greatly, so that the center of gravity position can be restored. That is, it is determined that it can be stably inverted, and the transition from the grounded state to the off-ground state is continued. Then, as shown in FIG. 4D, the transition to the takeoff state is completed and cooperative control is performed.

  If the tilt angular velocity does not exceed the threshold value, it is determined whether the slide mechanism 68 has reached the slide end. If the slide end has been reached, stop the transition to the ground-off state and return to the grounding state. If the slide end has not been reached, the tilt angular velocity may exceed the threshold before reaching the slide end. For this reason, the transition to the takeoff state is continued until the slide end is reached. Then, as shown in FIG. 4D, the transition to the takeoff state is completed and cooperative control is performed.

  By controlling in this way, it can be determined whether or not the posture can be changed to the opposite side (rear side) by slide driving. That is, it is examined whether it can be recovered from the forward inclined posture by driving the slide mechanism 68 after the inclination angle becomes positive by driving the swing arm and the inclination angle becomes positive. In other words, it is determined whether the center of gravity position deviation does not exceed the limit value and the posture can be recovered by the movement of the center of gravity position by the slide mechanism 68. For example, when the slide mechanism reaches the slide end at a stage where the tilt angular velocity does not exceed the negative threshold, the slide mechanism 68 cannot be driven any more. For this reason, even if the control target value is calculated by cooperative control, the slide mechanism 68 does not move any further. The tilt angle does not become the target tilt angle, and even if the drive wheel 78 is driven, the inversion cannot be stabilized. That is, since the slide mechanism 68 cannot be further driven, it cannot follow the target slide speed. The rotational torque required to follow the control target value exceeds the specifications of the motors 34 and 36 of the drive wheels 78. Inverting cannot be stabilized, and the moving body 100 will fall or runaway. Therefore, the swing arm is driven so as to lower the vehicle body 12, and the auxiliary wheel 51 is grounded. Thereby, a moment becomes small, the fall and runaway of the mobile body 100 can be prevented, and safety can be further improved.

  On the other hand, when the inclination angular velocity exceeds the threshold value or when it has not reached the slide end, the transition from the ground contact state to the takeoff state is continued. That is, it is determined that the center-of-gravity position shift can be recovered, and the inversion control in the detached state is started.

  Thus, when the inclination changes until the slide end, the inversion control is started. That is, as shown in FIG. 4D, the drive wheels 78 are driven to invert. Specifically, the control unit 80 calculates cooperative control and calculates a control target value. Then, the amplifiers 34a and 36a of the drive wheels 78 are commanded with a torque value corresponding to the control target value. Further, the amplifier 70a is instructed to follow the slide speed that is the control target value. Then, feedback control is performed until the target value (inverted stable) is reached. Thereby, it can transfer to a detached state from a grounding state stably. Moreover, since it is not necessary to provide a new sensor to detect the weight, it is possible to prevent an increase in electrical wiring and an increase in cost. That is, it is possible to determine whether the inversion control is possible by using the gyro sensor 48 used for the inversion control, the passenger seat drive motor 70 and the encoder thereof. Therefore, an increase in the number of parts can be prevented.

  In the present embodiment, when the slide force F is smaller than the threshold value and the slide mechanism 68 does not move to the slide end, the transition from the ground contact state to the ground release state is completed. Then, move upside down. That is, when the sliding force F is smaller than the threshold value and does not reach the sliding end during the transition from the grounded state to the ground-off state, the transition to the ground-off state is completed and the vehicle is inverted by cooperative control. I do. Further, when the sliding force F is larger than the threshold during the transition from the grounding state to the grounding state, or when reaching the sliding end, the transition to the grounding state is stopped and returned to the grounding state. . As a result, the front and rear auxiliary wheels 51 are brought into contact with the ground and become in a stable posture.

  When the slide mechanism 68 reaches the slide end, the vehicle body 77 cannot be further slid backward. Therefore, when the slide mechanism 68 reaches the slide end, it is necessary to maintain the inversion only by driving the drive wheels 78. Since the limit value of the deviation of the center of gravity is over, it becomes difficult to travel stably. For this reason, if cooperative control is performed, there is a risk of falling or running away. That is, since the vehicle must be driven only by driving the drive wheels 78, the load on the motors 34 and 36 of the drive wheels 78 increases. For this reason, rapid acceleration is required and there is a risk of runaway. Control target values exceeding the specifications of the right wheel drive motor 34 and the left wheel drive motor 36 are output. In this case, the inversion cannot be maintained, and the auxiliary wheel 51 may collide with the ground, or the moving body 100 may fall. Even when the slide mechanism 68 reaches the slide end, it is determined that the limit value of the center-of-gravity position shift is exceeded, and the grounding state is restored.

  As described above, when the limit values of the weight and the displacement of the center of gravity are exceeded, the grounding state is restored. Thereby, the runaway of the mobile body 100 and a fall can be prevented. Therefore, the safety at the time of shifting from the grounded state to the off-ground state can be further improved. As a result, the vehicle can travel more safely from the grounded state via the ground-off state.

  In the above description, the mechanism for moving the position of the center of gravity of the vehicle body portion 77 back and forth has been described as the slide mechanism 68, but the present embodiment is not limited to this. For example, a rotation mechanism that rotates the vehicle body 77 around the rotation axis C3 may be used. In this case, similarly to the slide mechanism, when reaching the mechanical end of the rotating mechanism, the grounding state is restored. In this way, when the drive unit that moves the center of gravity of the vehicle body 77 back and forth has a drive range, it may be restored to the grounded state when it reaches the end of the drive range. The driving range may be a mechanically drivable range or a range determined by a sensor or the like. Further, when the driving force of the rotation mechanism or the slide mechanism 68 exceeds the threshold value, the ground state may be recovered.

  In the above description, it is determined whether the displacement of the center of gravity is over the limit value depending on whether the tilt angular velocity exceeds the threshold value. However, the present embodiment is not limited to this. For example, it may be determined whether or not the center-of-gravity position shift exceeds a limit value depending on whether or not the tilt angular velocity has changed. That is, the posture cannot be recovered if the slide end is reached without changing the inclination angular velocity. On the other hand, when the inclination changes due to the driving of the slide mechanism 68, the posture of the moving body 100 changes greatly. The center-of-gravity position shift can be recovered. On the other hand, when the tilt angular velocity has not changed, the posture cannot be recovered by the operation of the slide mechanism 68. That is, the limit value of the center-of-gravity position shift is exceeded, and the vehicle stops in a three-wheel grounding state as shown in FIG. In such a case, it is determined that the posture cannot be recovered by cooperative control. Then, the swing arm joint 67 is driven to ground the auxiliary wheel 51.

  Further, in the above description, the auxiliary wheel 51 is grounded when it is determined that the limit value of the center-of-gravity position shift is exceeded, but the present embodiment is not limited to this. For example, the height of the vehicle body 12 may be lowered and the moment may be lowered without completely grounding the auxiliary wheel. By lowering the moment, it is possible to widen the allowable range of the displacement of the center of gravity. As a result, the limit value of the center-of-gravity position shift does not exceed the limit value and can be inverted by cooperative control. Safety can also be improved by such control.

  Next, a method for controlling the moving body 100 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a control method. First, the swing arm joint 67 is moved to a specified angle (step S101). As a result, the vehicle body portion 77 moves up and shifts from the ground contact state to the ground release state. Then, to maintain the inverted position, the slide is moved (step S102). Here, since the posture of the moving body 100 is inclined forward, the slide mechanism 68 is slid back. Alternatively, the slide may be moved by a predetermined slide amount. Then, the slide force F is obtained from the measured slide torque value, and it is determined whether or not the slide force F is within an allowable range (step S103). The sliding force F is obtained from the torque value output from the passenger seat drive motor 70. Since the sliding force F corresponds to the weight of the vehicle body 77, the weight can be detected by the driving force of the passenger seat driving motor 70. Then, it is determined whether the sliding force F is within the allowable range or outside the allowable range.

  In this way, by comparing the sliding force F with the threshold value, it can be determined whether or not the weight of the vehicle body portion 77 exceeds the prescribed weight. If the sliding force F exceeds the threshold value, it is determined that the weight is over, and the angle of the swing arm joint 67 is restored (step S104). As a result, the control ends in the four-wheel state in which the vehicle body 12 is lowered and the auxiliary wheel 51 is grounded.

  If the slide force F is within the allowable range in step S103, the slide is further moved (step S105). Thereafter, the tilt angular velocity is measured, and it is determined whether or not the tilt angular velocity has changed (step S106). That is, it is examined whether the tilt angular velocity measured by the gyro sensor 48 is changed by the sliding mechanism 68 sliding. Thereby, it can be determined whether the inclination changes before the slide end. For example, when the tilt angular velocity changes due to the driving of the slide mechanism 68, the posture of the moving body 100 changes. When the tilt angular velocity is changed by driving the slide mechanism 68, the posture can be recovered. In this step, instead of determining whether or not the tilt angular velocity has changed, it may be determined whether or not the tilt angular velocity has exceeded a threshold value as described above.

  If the tilt angular velocity has not changed, the slide position of the slide mechanism 68 is measured to determine whether or not the mechanical end (slide end) has been reached (step S107). The slide position of the slide mechanism 68 can be measured by, for example, an encoder provided in the passenger seat drive motor 70. When reaching the mechanical end, the angle of the swing arm joint 67 is returned to the original (step S108). That is, when reaching the mechanical end, it is determined that the moving body 100 cannot be recovered, and the inversion by the cooperative control is abandoned. Control ends when the auxiliary wheel 51 is in a four-wheel state with the ground. If the mechanical end has not been reached, the process returns to step S106 to determine whether the tilt angular velocity has changed.

  When it is determined in step S106 that the tilt angular velocity has changed, the inversion control is started (step S109). Here, cooperative control calculation of the drive wheel 78 and the slide mechanism 68 is performed to calculate a control target value. Based on the target control value, the drive wheel 78 and the slide mechanism 68 are driven in a coordinated manner (step S110, step S111). This makes it possible to move while inverting. And it is determined whether it converged to the target position (step S112). For example, it is determined whether or not the swing arm joint 67 has reached the target angle and the moving body 100 has reached the target position and target speed according to the input from the operation module 46. Alternatively, when stopping on the spot, feedback control is performed until the tilt angle converges to the target tilt angle and the tilt angular velocity reaches zero. When it converges to the target position, the control is finished in the inverted two-wheel state in which the two auxiliary wheels 51 have left the ground. If it has not converged to the target position, the control from step S109 is repeated.

  Thus, by controlling, the safety at the time of shifting from the grounded state to the off-ground state can be improved. That is, when the weight or the center of gravity shift exceeds the limit value, the inversion by the cooperative control is not performed, so that the overturn or the runaway can be prevented and the safety can be improved. Further, the weight is detected from the sliding force F, and the balance of the center of gravity is examined by sliding movement to the slide end. From these two, it is possible to check whether it is possible to invert, and it is possible to reliably prevent a fall or runaway.

In the above description, the weight is detected by the sliding force F, but the present embodiment is not limited to this. For example, the weight may be detected by applying a step torque to the drive wheels. That is, torque is applied to the drive wheels 78 in a stepwise manner. Specifically, the period for applying torque and the period for not applying torque are alternately repeated. Then, the encoders 52 and 54 detect the rotational angular velocity of the driving wheel 78 driven by the step torque. Thereby, the weight of the vehicle body part 77 can be estimated.
Thus, the weight can be detected by the driving force of the motors 34 and 36 that drive the drive wheels 78 and the passenger seat drive motor 70 that drives the slide mechanism 68. Then, it is determined whether the weight is over based on the detected weight. Thereby, it is not necessary to provide a dedicated weight sensor, and the number of parts can be reduced. Further, the weight can be accurately detected even if the passenger's state changes. That is, when a normal weight sensor is used, the weight cannot be accurately detected unless a passenger is on the weight sensor. However, as in the present embodiment, the weight can be accurately detected by detecting the weight according to the driving force of the driving unit such as a motor. Thereby, it can be determined reliably whether it can be inverted and the safety | security of an inversion operation | movement can be improved more.

  Although the two-wheeled moving body 100 has been described in the present embodiment, the number of driving wheels is not limited to this. A single-wheel-type moving body or a moving body having three or more driving wheels may be used. Of course, the number of arms constituting the swing arm may be two or three or more. The joint that drives the passenger seat 74 is not limited to a linear motion joint, and may be a rotating joint, for example. In this case, the rotating joint rotates the boarding seat 74 in the front-rear direction to change the position of the center of gravity of the boarding seat 74 and the passenger. Further, not only forward movement but also backward movement can be controlled in the same manner.

  In the above example, it is described that the operator is on the moving body 100, but the present invention is not limited to this. For example, the present invention can be applied to a mobile body that is operated remotely. Furthermore, in the above description, the moving body 100 having the boarding seat 74 has been described. However, a moving carriage for object transportation may be used. Of course, other mobile bodies such as a mobile robot may be used.

It is a side view which shows the structure of the moving body concerning embodiment of this invention. It is a front view which shows the structure of the mobile body concerning embodiment of this invention. It is a block diagram which shows the structure of the control system of the moving body concerning embodiment of this invention. It is a side view for demonstrating the attitude | position of the mobile body concerning embodiment of this invention. It is a flowchart which shows the control method of the moving body concerning embodiment of this invention.

Explanation of symbols

12 body, 17 right swing arm, 19 left swing arm,
18 right drive wheel, 20 left drive wheel, 21 upper right link, 22 upper left link,
26 Right mount, 28 Left mount,
30 axles, 32 axles, 34 right wheel drive motor, 36 left wheel drive motor,
41 main body, 42 operation lever, 43 operation angle sensor, 44 battery module,
46 operation module, 48 gyro sensor, 51 auxiliary wheel,
52 right wheel encoder, 54 left wheel encoder, 55 auxiliary wheel support block,
58 sensor, 60 right swing arm drive motor, 62 right swing shaft 64 left swing arm drive motor, 66 left swing shaft 67 swing arm joint, 68 slide mechanism,
70 Boarding seat drive motor, 72 Rack and pinion, 74 Boarding seat,
76 upper body part, 77 car body part, 78 drive wheel,
80 control unit, 81 swing arm control unit, 82 driving wheel / slide cooperative control unit,
83 sensors, 100 moving objects,

Claims (8)

A chassis that rotatably supports the wheels;
A first drive unit that rotationally drives the wheels;
A vehicle body part rotatably supported with respect to the chassis via a support member;
A second drive section for driving the vehicle body section;
A third drive section for changing the height of the vehicle body section;
A control unit that controls the first drive unit, the second drive unit, and the third drive unit, and an inverted wheel type moving body comprising:
The control unit is
When the driving force of the first or second driving unit exceeds a threshold value, or when reaching the end of the driving range of the second driving unit, the third body unit is lowered to lower the vehicle body unit. Control the drive of the
When the driving force of the first or second driving unit does not exceed a threshold value and the second driving unit has not reached the end of the driving range, the inverted wheel type moving body is inverted. An inverted wheel type moving body that controls the first and second drive units so as to move while moving.   The control unit lowers the vehicle body part when the end of the driving range is reached when the tilt angular velocity of the posture of the inverted wheel type moving body does not change or does not exceed the threshold value. The inverted wheel type moving body according to claim 1, wherein the three driving units are controlled. The second drive unit has a slide mechanism that slides the vehicle body part back and forth,
The inverted wheel type moving body according to claim 1 or 2, wherein when the sliding force of the second drive unit does not exceed a threshold value, the control unit controls the vehicle body unit to be lowered. An auxiliary wheel that moves up and down when the third drive unit is driven;
When the driving force of the first or second driving unit exceeds a threshold value or reaches the end of the driving range of the second driving unit, the control unit controls the third driving unit. The inverted wheel type moving body according to any one of claims 1 to 3, wherein the auxiliary wheel is grounded by control. A chassis that rotatably supports the wheels;
A first drive unit that rotationally drives the wheels;
A vehicle body part rotatably supported with respect to the chassis via a support member;
A second drive section for driving the vehicle body section;
An auxiliary wheel provided apart from the wheel;
A third drive unit that switches between a grounded state where the auxiliary wheel is grounded and a grounded state where the auxiliary wheel is grounded, and a control method for an inverted wheel type moving body comprising:
When the driving force of the first or second driving unit exceeds a threshold value, or when reaching the end of the driving range of the second driving unit, the third body unit is lowered to lower the vehicle body unit. Controlling the drive unit of
When the driving force of the first or second driving unit does not exceed a threshold value and does not reach the end of the driving range of the second driving unit, the inverted wheel type moving body is inverted. And a step of controlling the first and second drive units so as to move while moving the inverted wheel type moving body.   The control unit lowers the vehicle body part when the end of the driving range is reached when the tilt angular velocity of the posture of the inverted wheel type moving body does not change or does not exceed the threshold value. The control method of the inverted wheel type moving body of Claim 5 which controls 3 drive parts. The second drive unit has a slide mechanism that slides the vehicle body part back and forth,
The method for controlling an inverted wheel type moving body according to claim 5 or 6, wherein the vehicle body is lowered when a sliding force of the sliding mechanism does not exceed a threshold value. An auxiliary wheel that moves up and down when the third drive unit is driven;
The auxiliary wheel is grounded when a driving force of the first or second driving unit exceeds a threshold value or when an end of a driving range of the second driving unit is reached. The control method of the inverted wheel type moving body according to any one of the above.

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