JP2009101817A - Inverted wheel type movable body and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverted movable body capable of being safely transferred to an inverted travelling state from an auxiliary wheel grounding state (ridable state) and a control method of the inverted movable body. <P>SOLUTION: This inverted wheel type movable body has two or more than two wheels 15, two or more than two auxiliary wheels 16 to assist the wheels 15 and a stabilization control means to maintain inversion. The stabilization control means transfers the auxiliary wheel grounding state to the inverted state through a state grounding a part of the auxiliary wheels. Additionally, the stabilization control means has a sensor 17 to compute floor pressure between the wheels 15 and the ground and a distance measuring means to measure a distance between an obstruction and itself, computes a distance required to transfer to the inverted state in accordance with the floor pressure and starts inverting motion when the required distance is shorter than the distance to the obstruction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inverted wheel type moving body having two or more wheels and two or more auxiliary wheels or stoppers for assisting the wheels, and a control method thereof.

  FIG. 13 is a schematic diagram showing a conventional inverted two-wheeled robot. The inverted two-wheeled robot 101 includes a vehicle body 111 and a swing arm 112 attached to the vehicle body 111 and lifting the vehicle body by rotating. The swing arm 112 is coupled to the vehicle body 111 by a swing arm shaft 113 and is configured to be able to slide the vehicle body 111 parallel to the floor surface. A driving wheel shaft 114 is provided on the side of the swing arm 112 opposite to the swing arm shaft 113. Then, the driving wheel 115 is driven to rotate about the driving shaft 114, thereby moving the inverted two-wheeled robot 101. Two auxiliary wheels (stoppers) 116 that assist one driving wheel 115 are provided on the vehicle body 111.

As a stand-up operation of a conventional inverted two-wheeled robot, first, the swing arm shaft 113 is driven from the state where the front and rear auxiliary wheels are grounded (FIG. 13A), the vehicle body 111 is lifted and the front and rear auxiliary wheels 116 are lifted from the ground. Release (FIG. 13B). At this time, the front and rear auxiliary wheels 116 are released almost simultaneously. Next, the vehicle body 111 is raised upward while the swing arm shaft 113 is continuously driven. At the same time, the vehicle body 111 is raised while continuously driving the drive shaft 114. At the same time, the inversion control with the drive wheel 115 is started (FIG. 13C).
JP 2006-205839 A

  However, in such a method, when the swing arm shaft 113 is driven, the front and rear auxiliary wheels 116 are not necessarily separated from the ground due to the balance of the center of gravity on the drive wheels 115, and there are cases where the assumed rising operation cannot be performed. Even when the front and rear auxiliary wheels 116 are separated from the ground, if the height is not secured, there is a risk that the auxiliary wheels 116 may come into contact with the ground when the robot 101 shakes back and forth.

  Further, in FIG. 14B, the posture of the robot 101 is tilted unless the inversion control is started as soon as possible. However, even if the inversion control is started before the auxiliary wheel 116 is sufficiently separated from the ground, the auxiliary wheel 116 does not move. There is a possibility of grounding (FIG. 14C). That is, in the inverted traveling robot 101, a transition operation (rise operation) from “the state where the auxiliary wheels 116 are grounded” to “the state where all the auxiliary wheels 116 are separated and are kept inverted by the drive shaft 114”. Medium, it tends to become unstable due to unexpected external force.

  The present invention has been made to solve such a problem, and can control an inverted moving body and an inverted moving body that can safely transition from an auxiliary wheel grounding state (a boardable state) to an inverted traveling state. It aims to provide a method.

  In order to solve the above-described problems, an inverted wheel type moving body according to the present invention includes two or more wheels, two or more auxiliary wheels that assist the wheels, and stabilization control means for maintaining the inversion. And the stabilization control means shifts from the auxiliary wheel grounding state to the inverted state through a state in which a part of the auxiliary wheel is detached.

  In the present invention, since a part of the auxiliary wheel is separated from the grounded state of the auxiliary wheel and the rest is grounded, the state is shifted to the inverted state, so that stable inversion is possible.

  Moreover, it has a sensor which calculates a floor pressure between the said wheel and the ground, and can determine whether it transfers to the said inverted state based on the said sensor result.

  Further, the stabilization control means can calculate a distance necessary to shift to the inverted state based on the floor pressure. Whether to shift to the inverted state can be determined according to the required distance.

  Furthermore, it has a distance measuring means for measuring the distance to the obstacle, and the stabilization control means can start the inversion operation when the necessary distance is shorter than the distance to the obstacle. Safety can be ensured by performing the inverted operation only when the distance is shorter than the distance to the obstacle.

  Here, instead of the auxiliary wheel, a stopper may be provided.

  An inverted wheel type moving body control method according to the present invention is an inverted wheel type moving body control method having two or more wheels and two or more auxiliary wheels for assisting the wheels, in order to maintain the inverted state. And a stabilization control step of shifting from the auxiliary wheel grounding state to an inverted state via a state in which a part of the auxiliary wheel is grounded.

  ADVANTAGE OF THE INVENTION According to this invention, the control method of the inverted moving body and the inverted moving body which can transfer to an inverted driving | running | working state safely from an auxiliary wheel grounding state (boarding possible state) can be provided.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to an inverted two-wheeled mobile body with two or more auxiliary wheels.

  FIG. 1A and FIG. 1B are diagrams showing an inverted two-wheeled mobile body (hereinafter referred to as an inverted traveling robot) according to the present embodiment. In addition, although Fig.1 (a) has shown the side view, in actuality, it has at least two or more wheels toward the back of the page. In the present embodiment, a two-wheel inverted traveling robot is described, but three or more wheels may be provided.

  The inverted traveling robot 1 includes a vehicle body 11 and a swing arm 12 attached to the vehicle body 11 and lifting the vehicle body by rotating. The swing arm 12 is coupled to the vehicle body 11 by a swing arm shaft 13 so that the vehicle body 11 parallel to the floor surface can slide. A drive wheel shaft 14 is provided on the opposite side of the swing arm 12 from the swing arm shaft 13. Then, the driving wheel 15 is rotationally driven around the driving wheel shaft 14 to move the inverted traveling robot 1. Two auxiliary wheels (or stoppers) 16 that assist one driving wheel 15 are provided on the vehicle body 11. Further, the pressure sensor 17 is grounded to the auxiliary wheel 16, and the load can be measured. Even if it is not the auxiliary wheel 16, you may provide the pressure sensor 17 in parts other than the driving wheel which installs on a ground and supports so that a robot may not fall down, such as a stopper.

  This inverted traveling robot 1 has an unstable degree of freedom and has the following characteristics. That is, an attitude angle sensor and an attitude angular velocity sensor for sequentially calculating the state of the inverted traveling robot 1, and a stabilization controller for calculating a control amount necessary for maintaining the inversion from various sensor values (state amounts); And a drive unit that drives a wheel drive motor in accordance with the output of the stabilization controller (none of which is shown). In the state where the inverted traveling robot 1 is not controlling anything, as shown in FIG. 1A, the auxiliary wheels are grounded and maintained in a stable state.

  While the stabilization control controller (inverted traveling controller) is operating, the inverted state can be maintained with only the drive wheels 15 as shown in FIG. When any travel command value is given, the vehicle travels according to the command travel pattern while maintaining the inverted stable state. When the traveling is completed, the state returns to the state of FIG. 1A at an appropriate timing, and the stabilization controller is turned off.

  Next, an operation for transitioning from the state of FIG. 1A to the state of FIG. 1B (hereinafter also referred to as a rising operation) will be described. 2 and 3 are diagrams illustrating the inverted traveling robot in the middle of the transition. FIG. 4 is a diagram illustrating a rising operation.

  Each axis of the inverted traveling robot 1 is driven so that a part of the auxiliary wheel 16 is released before the transition operation (rise) for shifting the auxiliary wheel 16 from the grounded state to the inverted state is started, and the stationary state shown in FIG. A rise operation is executed after passing through the state. Thereby, it is possible to reduce the risk of the auxiliary wheels coming into contact with the ground during the rising operation by keeping some of the auxiliary wheels away from the ground while maintaining stability.

  In this way, since the start-up operation is started after passing through the “state in which a part of the auxiliary wheel 16 is separated from the ground”, some of the auxiliary wheels 16 have been separated in advance. The risk that the auxiliary wheel 16 is grounded is reduced. Further, as shown in FIG. 3, the risk of the auxiliary wheel being grounded during the stand-up operation is further reduced by positively storing the released auxiliary wheel 16 in the vehicle body and separating it from the ground.

  Here, in this embodiment, as shown in FIG. 4 (b), a one-side auxiliary wheel grounding state is provided, but from the state of FIG. 4 (a) in which the front and rear auxiliary wheels 16 are grounded, FIG. 4 (b). Any method may be used for the transition to the one-side auxiliary wheel grounding state. For example, an operation of moving the swing arm shaft 13 and raising the center of gravity may be performed. As a result, while maintaining the stability of the multipoint grounding state, the risk of the auxiliary wheel 16 being grounded during the stand-up operation can be reduced by securing the distance between the other auxiliary wheel 16 and the ground. .

  Furthermore, the inverted traveling robot 1 according to the present embodiment includes at least one pressure-sensitive sensor 17 that can measure pressure in at least one axial direction between the vehicle body 11 and the ground point. Then, in the “state in which a part of the auxiliary wheel 16 is separated from the ground”, the balance of the center of gravity is corrected according to the weight measured by the pressure sensor 17 of the auxiliary wheel 16, and the amount of movement necessary for starting is calculated. A process of determining whether to start up is performed by comparing the calculated amount of movement with the distance between the surrounding obstacles and humans.

  That is, by detecting the floor reaction force with the pressure-sensitive sensor 17 installed on the auxiliary wheel 16 that is in contact with the ground, it is possible to predict the amount of movement required until the inversion is completed before the start-up operation is started. The distance between the inverted traveling robot 1 and a surrounding obstacle such as a pedestrian or a wall is measured by a distance sensor, etc., and the result is compared with the predicted amount of rising movement, thereby obstructing the obstacle by the rising action. It can be determined whether or not it collides with. If it is determined that there is a collision, safety is ensured by giving up (interrupting) the rising motion. When it is determined that there is no collision, the rising operation is started. Thereby, the problem of colliding with surrounding obstacles during the rising operation can be avoided.

  Next, a method for determining whether to perform a rising operation based on the sensor value of the pressure sensor will be described in more detail. FIG. 5 is a diagram showing a one-side auxiliary wheel grounding state. The load (floor reaction force: F_offset) applied to the grounding point is measured by the sensor value of the pressure-sensitive sensor 17 at this time, and the distance (D_offset) from the driving wheel shaft 14 to the sensor is multiplied to generate around the driving wheel shaft. Moment (M_offset) can be detected.

  FIG. 6 is a diagram for explaining the movement amount X_offset necessary for the rising operation. FIG. 7 is a map showing the relationship between the moment around the drive axis and the movement amount. The horizontal axis shows the measured value M_offset of the moment, and the vertical axis shows the movement amount X_offset. When the inversion control is started from the one-side auxiliary wheel grounding state, the movement amount X_offset required until the start-up is completed is also affected by the operation of the swing arm shaft 13, but the driving wheel shaft in the one-side auxiliary wheel grounding state described above. It is possible to predict by investigating in advance the relationship between the moment (M_offset) generated around and the performance / characteristics of the controller.

  For example, as shown in FIG. 7 using a computer simulation or the like in advance, the relationship between the moment applied to the drive wheel shaft and the required amount of movement in the one-side auxiliary wheel grounding state is investigated and plotted on a map. The moment M_offset generated around the driving wheel axis just before starting the rising motion is calculated from the load (floor reaction force: F_offset) applied to the contact point and the distance D_offset from the driving wheel shaft to the sensor. The amount of movement of the robot can be predicted.

  Next, let us consider a case in which the distance between an obstacle or a person existing around the inverted traveling robot 1 can be observed in the grounding state on one side auxiliary wheel. FIG. 8 is a graph showing the relationship between the amount of movement required for the rising operation and the distance to the obstacle. FIG. 9 is a flowchart showing a method for determining whether or not the rising operation is possible. The inverted traveling robot 1 can determine whether to start the rising operation according to the following procedure or whether it is safe to start.

  First, all the auxiliary wheels 16 or the stoppers are brought into contact with the ground and stationary (step S1). Next, a part of the auxiliary wheels 16 or the stopper is released (step S2). At this time, the load applied to the auxiliary wheel is measured by the pressure sensor 17, and based on this value, the moment or the moving amount necessary for rising is estimated (step S3). At the same time, the distance to the obstacle or the magnitude of the moment is measured (step S4).

  Next, as shown in FIG. 8, a threshold line corresponding to the distance to the observed obstacle is drawn on the map shown in FIG. 7 prepared in advance. Then, intersections P and Q where the threshold line and the offset amount intersect are found on the map. The horizontal axis values (M_p, M_q) of the intersections P, Q are compared with the actually measured values (for example, moments M_1, M_2). Note that the estimated movement amount may be compared with a threshold value. Then, if the measured values M_1 and M_2 are between M_p and M_q, it is determined to be safe and a rising operation is started (step S5: YES). If the measured values are not between M_p and M_q, it is dangerous. Judgment is made and the rising operation is interrupted. In this case, if M_1, the start-up operation is started, but if M_2, it is determined as dangerous and the start-up operation is stopped. If the center of gravity position can be changed (step S7: YES), the center of gravity position is changed (step S6), the necessary movement amount or moment value is calculated again, and the processing from step S3 is repeated.

  In this embodiment, when the inverted two-wheeled mobile body with two or more auxiliary wheels is inverted, at least one auxiliary wheel is grounded while at least one auxiliary wheel is grounded from the state where all the auxiliary wheels are installed. After going through the state, turn it upside down. Thereby, stable inversion is possible.

  Whether or not the inverted two-wheeled moving body is inverted based on the floor reaction force of the one or more auxiliary wheels that are installed with at least one auxiliary wheel in contact with the ground, and whether or not to invert from the moving distance. Determination means for determining This makes it possible to avoid hitting an object due to inversion.

  Next, a specific example of the inverted traveling robot according to the present embodiment will be described. The inverted traveling robot according to this specific example is an inverted wheel type moving body that moves by the inverted pendulum control. The inverted traveling robot 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. The inverted traveling robot moves in accordance with the operation amount operated by the operator while maintaining the inverted state.

  The configuration of the inverted traveling robot 200 according to a specific example of the present embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a side view schematically showing the configuration of the inverted traveling robot 200, and FIG. 11 is a front view schematically showing the configuration of the inverted traveling robot 200.

  As shown in FIG. 11, the inverted traveling robot 200 is an inverted wheel type moving body (running body), and includes a right drive wheel 218, a left drive wheel 220, a right swing arm 217, and a left swing arm 219. The vehicle body 212 is provided. The vehicle body 212 is a part of the upper body part of the inverted traveling robot 200 disposed above the right drive wheel 218 and the left drive wheel 220. Here, a traveling direction of the inverted traveling robot 200 (a direction perpendicular to the paper surface of FIG. 11) is a front-rear direction, and a direction perpendicular to the front-rear direction on a horizontal plane is a left-right direction (lateral direction). Therefore, FIG. 11 is a diagram of the inverted traveling robot 200 viewed from the front side in the traveling direction, and FIG. 10 is a diagram of the inverted traveling robot 200 viewed from the left side.

  During traveling, the right swing arm 217 and the left swing arm 219 adjust the vehicle height. Furthermore, one or both swing arms are driven to adjust the left and right inclination angles of the vehicle body 212 with respect to the ground. For example, it is assumed that only the right drive wheel 218 climbs 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 218 is higher than the left drive wheel 220. Therefore, the joint of the right swing arm 217 is driven so that the right driving wheel 218 is closer to the direction of the vehicle body 212. As a result, the height of the right drive wheel 218 can be absorbed, and the vehicle body 212 can be leveled in the lateral direction (left-right direction).

  A right mount 226 is fixed to the right swing arm 217 side end side, and supports the right drive wheel 218 via the axle 230 so as to be rotatable. The right drive wheel 218 is fixed to the rotation axis C1 of the right wheel drive motor 234 via the axle 230. The right wheel drive motor 234 is fixed in the right mount 226 and functions as a wheel drive unit (actuator).

  A left mount 228 is fixed to the side end side of the left swing arm 219 and supports the left drive wheel 220 via an axle 232 so as to be rotatable. The left drive wheel 220 is fixed to the rotation axis C <b> 2 of the left wheel drive motor 236 via the axle 232. The left wheel drive motor 236 is fixed in the left mount 228 and functions as a wheel drive unit (actuator). The right driving wheel 218 and the left driving wheel 220 are a pair of wheels that are in contact with the ground and rotate substantially coaxially. As the right driving wheel 218 and the left driving wheel 220 rotate, the inverted traveling robot 200 moves. Also, the right wheel drive motor 234 and the left wheel drive motor 236 serve as drive wheel motors for driving the wheels. The right mount 226 and the left mount 228 serve as a chassis that rotatably supports the left and right drive wheels.

  The right wheel drive motor 234 and the left wheel drive motor 236 (hereinafter also referred to as motors 234 and 236) 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 218 and the left driving wheel 220 may be collectively referred to as driving wheels.

  The right mount 226 includes a right wheel encoder 252. The right wheel encoder 252 detects a rotation angle as a rotation amount of the right drive wheel 218. The left mount 228 includes a left wheel encoder 254. The left wheel encoder 254 detects a rotation angle as a rotation amount of the left drive wheel 220.

  The right swing arm 217 includes an upper right link 221, a right swing shaft 262, and a right swing arm drive motor 260. The left swing arm 219 includes an upper left link 222, a left swing shaft 266, and a left swing arm drive motor 264. An upper right link 221 and an upper left link 222 are fixed to the lower portion of the vehicle body 212. A right swing arm drive motor 260 is fixed to the upper right link 221 and drives the right swing arm 217 around the rotation axis C4 via the right swing shaft 262. A left swing arm drive motor 264 is fixed to the left swing shaft 266, and drives the left swing arm 219 around the rotation axis C5 via the left swing shaft 266. Thus, the right swing arm 217 is provided with a rotary joint that rotates about the rotation axis C4, and the left swing arm 219 is provided with a rotary joint that rotates about the rotation axis C5. A joint provided on the right swing arm 217 and the left swing arm 19 (hereinafter also referred to as swing arms 217 and 219) is referred to as a swing arm joint.

  A boarding seat drive motor 270, a rack and pinion 272, a gyro sensor 248, and a boarding seat 274 are attached to the vehicle body 12. Further, an upper right link 221 and an upper left link 222 are attached to the vehicle body 212 so as to face each other.

  A rack and pinion 272 is provided near the center of the vehicle body 212. The rack of the rack and pinion is provided along the front-rear direction. The boarding seat 274 is supported by the rack and pinion 272. That is, the passenger seat 274 is attached to the vehicle body 212 via the rack and pinion 272. The boarding seat 274 has a chair shape in which a passenger can sit. In addition, you may make it slide using a ball screw etc. instead of the rack and pinion 272. FIG.

  A passenger seat drive motor 270 is fixed to the upper portion of the vehicle body 212. The passenger seat 274 and the passenger seat drive motor 270 are connected by a rack and pinion 272. The passenger seat drive motor 270 rotates about the rotation axis C3. Thereby, a rotational force is applied to the pinion of the rack and pinion 272. The rotational motion of the passenger seat drive motor 270 is converted into linear motion by the rack and pinion 272. That is, when the passenger seat drive motor 270 is driven, the position of the passenger seat 274 relative to the vehicle body 212 slides back and forth. At this time, the position of the center of gravity of the passenger seat 274 and the occupant or the object is changed back and forth with respect to the vehicle body 212. As a means for changing the position of the center of gravity of the passenger seat 274 and the occupant or the loaded object relative to the vehicle body 212, in addition to the slide mechanism, it can be realized by a rotating shaft mechanism, a turning mechanism, or the like. . The power of the passenger seat drive motor 270 may be transmitted to the passenger seat 274 via a gear, a belt, a pulley, or the like. Here, the entire configuration that moves back and forth by the passenger seat drive motor 270 is a vehicle body portion 277. The vehicle body portion 277 includes a boarding seat 274, an operation module 246, and the like. Of course, when an actuator for driving the vehicle body 212 is provided, the vehicle body 212 is also included in the vehicle body portion 277. The passenger seat drive motor 270 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 217 is provided between the rotation axis C3 and the rotation axis C1, and a left swing arm 219 is provided between the rotation axis C3 and the rotation axis C2. The right swing arm drive motor 260 rotates the right swing arm 217 about the rotation axis C4, and the left swing arm drive motor 264 rotates the left swing arm 219 about the rotation axis C5. During normal travel, the rotation axis C1 to the rotation axis C5 are horizontal.

  Furthermore, the inverted traveling robot 200 is provided with two auxiliary wheels 251 in order to prevent the vehicle from falling. The auxiliary wheel 251 is rotatably supported with respect to the auxiliary wheel support block 255. The auxiliary wheel support block 255 is attached to the vehicle body 212. Here, one auxiliary wheel 251 is disposed on the front side of the driving wheel, and the other auxiliary wheel 251 is disposed on the rear side of the driving wheel. The auxiliary wheel 251 is a driven wheel and rotates according to the movement of the inverted traveling robot 200. In the inverted traveling robot 200 according to the present embodiment, a pressure sensor (not shown) is attached to the upper part of the auxiliary wheel 251. When the auxiliary wheel 251 contacts the ground, the vertical pressure at that time can be measured.

  When starting normal travel, the auxiliary wheel 251 is released by extending the swing arm joint. That is, the swing arm joint is moved so that the vehicle body 212 moves upward, and the auxiliary wheel 251 is moved upward. In the stop state, the auxiliary wheel 251 is grounded by contracting the swing arm joint. That is, by bending the swing arm joint, the vehicle body 212 approaches the ground, and the auxiliary wheel 251 moves downward. In this way, by moving the auxiliary wheel 251 up and down, it is possible to switch between a grounded state where the auxiliary wheel 251 is grounded and a grounded state where the wheel detaches and travels with two wheels. In this way, the inverted traveling robot 200 shifts from the grounding 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 251 is located on the front side above the rotation axes C1 and C2, and the rotation axis of the other auxiliary wheel 251 is located on the rear side above the rotation axes C1 and C2. That is, one of the auxiliary wheels 251 is disposed in front of the drive wheel axle, and the other is disposed in the rear of the drive wheel axle. Thereby, it is possible to prevent the inverted traveling robot 200 from tipping back and forth. 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 244 and a sensor 258 are housed in the vehicle body 212. The sensor 258 is, for example, an optical obstacle detection sensor, and outputs a detection signal when an obstacle is detected in front of the inverted traveling robot 200. The sensor 258 may be a sensor other than the obstacle sensor. For example, an acceleration sensor can be used as the sensor 258. Of course, two or more sensors may be used as the sensor 258. The sensor 258 detects the amount of change that changes according to the state of the inverted traveling robot 200. The battery module 244 is connected to the sensor 258, the gyro sensor 248, the right wheel drive motor 234, the left wheel drive motor 236, the right swing arm drive motor 260, the left swing arm drive motor 264, the passenger seat drive motor 270, the control unit 280, and the like. Supply power.

  A gyro sensor 248 is provided on the vehicle body 212. The gyro sensor 248 detects an angular velocity with respect to the inclination angle of the vehicle body 212. Here, the inclination angle of the vehicle body 212 is a degree of inclination from the axis at which the center of gravity of the inverted traveling robot 200 extends vertically above the axles 230 and 232. For example, the vehicle body 212 is inclined forward in the traveling direction of the inverted traveling robot 200. The case where the vehicle body 212 is inclined behind the direction of travel of the inverted traveling robot 200 is represented as “negative”. Therefore, when the vehicle body 212 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 inverted traveling robot 200.

  Further, 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 248 of roll, pitch, and yaw. As described above, the gyro sensor 248 measures the change in the tilt angle of the vehicle body 212 as the tilt angular velocity of the vehicle body 212. Of course, the gyro sensor 248 may be attached to another location. The tilt angular velocity measured by the gyro sensor 248 changes according to the change in the posture of the inverted traveling robot 200. That is, the inclination angular velocity is a change amount that changes in accordance with the position of the center of gravity of the vehicle body 212 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 246 is provided on the side surface of the passenger seat 74. The operation module 246 is provided with an operation lever (not shown) and a brake lever (not shown). The operation lever is an operation member for the passenger to adjust the traveling speed and traveling direction of the inverted traveling robot 200. The passenger can adjust the moving speed of the inverted traveling robot 100 by adjusting the operation amount of the operation lever. Further, the passenger can specify the moving direction of the inverted traveling robot 200 by adjusting the operating direction of the operating lever. The inverted traveling robot 200 can make forward, stop, reverse, left turn, right turn, left turn, and right turn according to the operation applied to the operation lever. When the passenger tilts the brake lever, the inverted traveling robot 200 can be braked. The traveling direction of the inverted traveling robot 200 is a direction perpendicular to the axles 230 and 232 in the horizontal plane. The operation module 246 is provided with a switch for switching the control mode.

  Further, a control unit 280 is mounted on the backrest portion of the passenger seat 274. The control unit 280 controls the right wheel drive motor 234 and the left wheel drive motor 236 following the operation performed by the occupant on the operation module 246, and controls the travel (movement) of the inverted traveling robot 200. The control unit 280 controls the right wheel drive motor 234 and the left wheel drive motor 236 in accordance with an operation on the operation module. As a result, the right wheel drive motor 234 and the left wheel drive motor 236 are driven with the acceleration and speed command values according to the operation in the operation module 246.

  The control unit 280 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 inverted traveling robot 200. And this control part 280 performs various control according to the control program stored, for example in ROM. The control unit 280 performs robust control, state feedback control, and PID control so as to achieve a desired acceleration and target speed in accordance with an operation on the operation module 246 and so that the inverted traveling robot 200 maintains an inverted position. The right wheel drive motor 234 and the left wheel drive motor 236 are controlled by known feedback control such as the above. Thereby, the inverted traveling robot 200 travels while accelerating and decelerating in accordance with the operation by the operation module 246.

  That is, the operation module 246 acquires the operation amount given by the passenger's operation, and outputs this operation amount to the control unit 280 as an operation signal. Then, the control unit 280 calculates the target acceleration and target speed of the inverted traveling robot 200 based on the operation signal, and feedback-controls the inverted traveling robot 200 so as to follow the target acceleration and target speed. Thereby, the inverted traveling robot 200 can be moved while being inverted.

  The control unit 280 also controls the right wheel drive motor 234, the left wheel drive motor 236, the right swing arm drive motor 260, the left swing arm drive motor 264, and the passenger seat drive motor 270. Here, the control unit 280 performs control so that the passenger seat drive motor 270 operates in cooperation with the right wheel drive motor 234 and the left wheel drive motor 236. That is, the driving wheel is rotated and the boarding seat 274 is slid so as to stabilize the inversion. Thereby, the inclination angle of the vehicle body 212 is reduced, and the inversion can be stabilized. In this way, the passenger seat drive motor 270 operates in cooperation with the right swing arm drive motor 260, the left swing arm drive motor 264, and the passenger seat drive motor 270.

  Next, the configuration of the control unit 280 that performs the above control will be described with reference to FIG. FIG. 12 is a block diagram illustrating a configuration of a control system including the control unit 280. As shown in FIG. 12, the control unit 280 includes a swing arm control unit 281 and a drive wheel / slide coordination control unit 282. Sensors 283 indicate various sensors provided in the inverted traveling robot 200, and include, for example, a gyrocene 2 sensor 48, a right wheel encoder 252, a left wheel encoder 254, a sensor 258, and the like. Then, the control unit 280 performs an inverted 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 283, for example. Then, feedback control is performed by multiplying the deviation by a predetermined feedback gain.

  The inverted traveling robot 200 is provided with an amplifier that drives and controls each motor. Here, the amplifiers provided in the right wheel drive motor 234, the left wheel drive motor 236, the right swing arm drive motor 260, the left swing arm drive motor 264, and the passenger seat drive motor 270 are an amplifier 234a, an amplifier 236a, and an amplifier 260a, respectively. Amplifier 264a and amplifier 270a. Each amplifier operates based on a control signal from the control unit 280. The control unit 280 outputs a control signal corresponding to the slide position and slide force to the amplifier 270a of the passenger seat drive motor 270. Further, a control signal corresponding to the wheel torque is output to the amplifiers 234a and 236a of the motors 234 and 236.

  The swing arm control unit 281 controls the right swing arm drive motor 260 and the left swing arm drive motor 264. For example, the swing arm control unit 281 outputs a control signal and drives the swing arm joint 267 so that the swing arm expands and contracts. Thereby, the grounding state in which the auxiliary wheel 251 is grounded and the grounding state in which the grounding is off can be switched. When traveling on an inclined surface, a control signal is output based on the output of the gyro sensor 248 and the like. As a result, the angle of the inclined surface is absorbed and the vehicle body 212 becomes horizontal. Control signals from the swing arm control unit 281 are input to the right swing arm drive motor 260 and the left swing arm drive motor 264 via the amplifiers 260a and 264a, and the right swing arm drive motor 260 and the left swing arm drive motor 264 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 267.

  The drive wheel / slide cooperative control unit 282 controls the right wheel drive motor 234, the left wheel drive motor 236, and the passenger seat drive motor 270 in a coordinated manner. That is, the drive wheel / slide cooperative control unit 282 calculates control target values for the right wheel drive motor 234, the left wheel drive motor 236, and the passenger seat drive motor 270. For example, the posture inclination angle, the posture inclination angular velocity, the rotational speed of the driving wheel, and the sliding speed of the passenger seat 274 are calculated as control target values. The inclination angular velocity of the vehicle body 212 is measured by the gyro sensor 248. Then, the inclination angle of the vehicle body 212 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 278 can be obtained from the outputs of the right wheel encoder 252 and the left wheel encoder 254. The slide speed of the slide mechanism 268 can be obtained from the output of an encoder provided in the passenger seat drive motor 270. The slide mechanism 268 can be obtained from the rotational torque of the passenger seat drive motor 270. 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 234, the left wheel drive motor 236, and the passenger seat drive motor 270 by the drive wheel / slide cooperative control unit 82 is not limited to the above control.

  In addition, the control unit 280 starts cooperative control after the auxiliary wheels 51 completely take off at the time of start-up when the ground state shifts to the takeoff state. That is, the inversion by the cooperative control is not started until the joint angle of the swing arm is driven to a certain angle. Therefore, after driving the joint angle of the swing arm to a certain angle, the operation of the drive wheel and the slide mechanism starts. By doing in this way, the safety | security at the time of starting can be improved. That is, at the stage where the auxiliary wheel 251 is in contact with the ground, the inclination angle and the inclination angular velocity of the posture may not change even if the inversion control is performed. If feedback control is performed based on these in a state where the tilt angle and tilt angular velocity do not change, the control cannot be stabilized. That is, even if the drive wheel is driven, the tilt angle and the tilt angular velocity do not change at all, so that the inversion control becomes unstable and may run away. However, as shown in the present embodiment, by detecting the angle of the swing arm joint, it can be confirmed that both of the auxiliary wheels are reliably separated from the ground. That is, it is possible to start up safely by starting the cooperative operation after the auxiliary wheel 251 has completely left the ground.

  Thus, when changing the height of the vehicle body 212, the control unit 280 determines whether or not the swing arm joint has been driven by a certain amount or more. That is, it is determined whether or not the joint angle of the swing arm joint is equal to or greater than a certain value. Then, after reaching a certain driving amount or more, cooperative control is started. That is, when the swing arm joint is driven by a predetermined angle or more, calculation of cooperative control is started. Therefore, the cooperative control is not calculated until the swing arm joint has a predetermined angle. Thereby, it is possible to prevent the inversion control from being performed in a state where the auxiliary wheel 251 is in contact with the ground, and it is possible to invert more stably.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

It is a figure which shows the inverted traveling robot concerning embodiment of this invention. It is a figure which shows the middle of the transition of the inverted traveling robot concerning embodiment of this invention. It is a figure which shows the middle of the transition of the inverted traveling robot concerning embodiment of this invention. It is a figure which shows the stand-up operation | movement of the inverted traveling robot concerning embodiment of this invention. It is a figure which shows the one-side auxiliary wheel grounding state of the inverted traveling robot concerning embodiment of this invention. It is a figure explaining movement amount X_offset required for the stand-up operation | movement of the inverted traveling robot concerning embodiment of this invention. The measured value M_offset of the moment is taken on the horizontal axis and the movement amount X_offset is taken on the vertical axis, and is a map showing the relationship between the moment around the drive axis and the movement amount. It is a graph which shows the relationship between the movement amount required for the stand-up operation | movement of the inverted traveling robot concerning embodiment of this invention, and the distance to an obstruction. It is a flowchart which shows the method of determining the propriety of the standing-up action of the inverted traveling robot concerning embodiment of this invention. It is a side view which shows typically the structure of the inverted traveling robot concerning the specific example of embodiment of this invention. It is a front view which shows typically the structure of the inverted traveling robot concerning the specific example of embodiment of this invention. It is a block diagram which shows the structure of the control system containing the control part concerning the specific example of embodiment of this invention. It is a schematic diagram which shows the conventional inverted two-wheeled robot. It is a schematic diagram which shows the stand-up operation | movement of the conventional inverted two-wheeled robot.

Explanation of symbols

1 Inverted traveling robot, 11 body, 12 swing arm,
13 swing arm shaft, 14 drive wheel shaft, 15 drive wheel,
16 auxiliary wheels, 17 pressure sensor, 200 inverted traveling robot,
212 body, 217 right swing arm, 218 right drive wheel,
219 Left swing arm, 220 left drive wheel, 221 upper right link,
222 Upper left link, 226 Right mount, 228 Left mount,
230, 232 axle, 234 right wheel drive motor,
234a, 236a, 260a, 264a, 270a amplifiers,
236 Left wheel drive motor, 244 battery module,
246 operation module, 248 gyro sensor, 251 auxiliary wheel,
252 Right wheel encoder, 254 Left wheel encoder, 255 Auxiliary wheel support block,
258 sensor, 260 right swing arm drive motor,
262 right swing axis, 264 left swing arm drive motor,
266 Left swing axis, 267 Swing arm joint, 268 Slide mechanism,
270 boarding seat drive motor, 272 rack and pinion, 274 boarding seat,
277 body part, 278 driving wheel, 280 control part, 281 swing arm control part,
282 Drive wheel / slide cooperative control unit, 283 sensors

Claims (9)

Two or more wheels,
Two or more auxiliary wheels for assisting the wheel;
Having stabilization control means for maintaining inversion,
The stabilization control means is an inverted wheel type moving body that shifts from an auxiliary wheel grounding state to an inverted state via a state in which a part of the auxiliary wheel is detached. Having a sensor for calculating floor pressure between the wheel and the ground;
The inverted wheel type moving body according to claim 1, wherein whether or not to shift to the inverted state is determined based on the sensor result. The inverted wheel type moving body according to claim 2, wherein the stabilization control means calculates a distance required to shift to the inverted state based on the floor pressure. It has a distance measuring means that measures the distance to the obstacle,
The inverted wheel type moving body according to claim 3, wherein the stabilization control means starts an inversion operation when the necessary distance is shorter than the distance to the obstacle. The inverted wheel type moving body according to any one of claims 1 to 4, further comprising a stopper instead of the auxiliary wheel. A method of controlling an inverted wheel type moving body having two or more wheels and two or more auxiliary wheels for assisting the wheels,
Control of an inverted wheel type moving body having a stabilization control process for maintaining an inverted state, wherein the stabilization wheel is transferred from an auxiliary wheel grounding state to a inverted state via a state in which a part of the auxiliary wheel is detached. Method. The vehicle according to claim 6, further comprising a step of determining whether or not to shift to the inverted state based on a sensor result of a sensor that calculates a floor pressure between the wheel and the ground. Control method. The method for controlling an inverted wheel type moving body according to claim 7, wherein, in the stabilization control step, a distance required to shift to the inverted state is calculated based on the floor pressure. 9. The inverted wheel according to claim 8, wherein in the stabilization control step, an inverted operation is started when the required distance is shorter than a distance measured by a distance measuring unit that measures a distance from an obstacle. Control method of mold moving body.

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