JP2011065231A - Mobile body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve attitude control for a mobile body in a state of suppressing that an occupant has uneasiness even if a ground contact face is inclined. <P>SOLUTION: A robot 100 is this mobile body wherein a body part 210 is turnably connected to wheel parts 220 and which performs space movement in an inverted state that the body part 210 is inverted to the wheel parts 220 according to drive of the wheel parts 220. The robot 100 measures, in the inverted state, distances between the body part 210 and the ground contact face with which the wheel parts 220 contact in a plurality of points, evaluates flatness of the ground contact face based on a measurement result thereof, and controls a relative position between the body part 210 and the wheel parts 220 according to an evaluation result of the flatness of the ground contact face to control an attitude of the mobile body. By adopting such a configuration, the attitude control of the mobile body can be achieved in the state of suppressing that the occupant has the uneasiness even if the ground contact face is inclined. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a moving body, and more particularly to an inverted two-wheeled moving body.

  In order to realize the inversion control of the moving body, it is common to incorporate a gyro sensor and an acceleration sensor in the moving body. In this case, the sensors incorporated in the moving body are required to consider the errors included in the sensor output and the deterioration of the sensor output over time.

  Patent Document 1 discloses a mechanism for estimating an inclination angle of a vehicle body with respect to a wheel with high accuracy in an inverted two-wheeled moving body. Specifically, a means for estimating the inclination angle of the vehicle body based on the inclination angle estimated based on the acceleration detected by the acceleration sensor and the angular velocity detected by the gyro sensor using the linear model equation of the moving body as an observer. And a movable body that changes the value of the observer gain K to approximate the inclination angle by the acceleration sensor or the inclination angle by the gyro sensor when estimating the inclination angle of the vehicle body.

Japanese Patent No. 4281777

  As described above, the posture control of the moving body is performed by incorporating the gyro sensor and the acceleration sensor into the moving body. However, the posture control of the moving body based on these sensors is based on the premise that the road surface (grounding surface) of the moving body is flat (that is, the road surface = the surface in which the axis along the vertical direction is a perpendicular line). Therefore, when the moving body moves on the inclined surface under such a precondition, depending on the angle formed by the inclined surface with respect to the axis along the vertical direction (hereinafter also referred to as the vertical axis). The main body may be tilted forward or rearward with respect to the wheels, which may cause anxiety to passengers riding on the main body. The inclined surface corresponds to a road surface that intersects the vertical axis at an angle other than a right angle.

  As is clear from the above description, there is a strong demand to realize posture control of the moving body in a manner that suppresses the passenger from feeling uneasy even if the road surface is inclined.

  The mobile body according to the present invention is connected to the wheel portion so that the main body portion is rotatable, and the main body portion is turned upside down with respect to the wheel portion in accordance with the driving of the wheel portion. When the moving body is in an inverted state, the distance between the grounding surface to which the wheel unit contacts the ground and the main body is measured at a plurality of locations, and the flatness of the grounding surface is determined based on the measurement result. The posture of the mobile body in the inverted state is controlled by controlling the relative position between the wheel part and the main body part according to the evaluation result of the flatness of the ground contact surface. By adopting this configuration, even when the ground contact surface is inclined, the posture control of the moving body can be realized in a manner that suppresses the passenger from feeling uneasy.

  It is good to control the attitude | position of the said mobile body in an inverted state by rotating the said main-body part with respect to the said wheel part according to the evaluation result of the flatness of the said ground plane. A moving body can be realized without increasing the number of parts.

  The posture of the mobile body in an inverted state is controlled by controlling the relative position between the wheel part and the main body part along an axis intersecting the grounding surface according to the evaluation result of the flatness of the grounding surface. Control, and good. The attitude control of the moving body can be realized at a high level.

  A first detecting means for detecting an angular velocity of the main body portion with respect to the wheel portion; and measuring a distance between a ground contact surface on which the wheel portion is grounded and the main body portion when the main body portion is in an inverted state with respect to the wheel portion. Generating a signal for controlling the posture of the robot in accordance with at least the angular velocity detected by the first detection unit, and based on a measurement value by the distance measurement unit, And signal generation means for generating a signal for correcting the posture of the robot.

  The first detection means may include a gyro sensor manufactured using a MEMS technology.

  The apparatus further comprises second detecting means for detecting the acceleration of the main body in a plurality of directions, and calculating an angle formed by the natural axis of the robot with respect to the vertical direction based on the detected acceleration. A signal for controlling the posture of the robot may be generated based on the output values of the first and second detection means.

  The angle calculated by the second detection unit may be corrected based on the measurement value of the distance measurement unit.

  According to the present invention, even if the ground contact surface is inclined, the posture control of the moving body can be realized in a manner that suppresses the passenger from feeling uneasy.

1 is a schematic perspective view of an inverted two-wheeled robot according to a first embodiment of the present invention. 1 is a schematic block diagram of an inverted two-wheeled robot according to a first embodiment of the present invention. 1 is a schematic diagram of an inverted two-wheeled robot that moves on a flat surface according to a first embodiment of the present invention. 1 is a schematic diagram of an inverted two-wheeled robot that moves on an inclined surface according to a first embodiment of the present invention. It is a schematic explanatory drawing which shows the axis set to the inverted two-wheeled robot concerning 1st Embodiment of this invention. It is explanatory drawing which shows the detection method of the inclined surface and inclination angle of the inverted two-wheeled robot concerning 1st Embodiment of this invention. It is explanatory drawing which shows the detection method of the vehicle body tilt angle of the inverted two-wheeled robot concerning 1st Embodiment of this invention. 1 is a schematic bottom view of an inverted two-wheeled robot according to a first embodiment of the present invention. 1 is a schematic bottom view of an inverted two-wheeled robot according to a first embodiment of the present invention. It is explanatory drawing which shows the direction change operation | movement of the inverted two-wheeled robot concerning 1st Embodiment of this invention. It is a schematic flowchart which shows operation | movement of the inverted two-wheeled robot concerning 1st Embodiment of this invention. It is a schematic flowchart which shows operation | movement of the inverted two-wheeled robot concerning 1st Embodiment of this invention. It is a schematic block diagram of the inverted two-wheeled robot concerning 2nd Embodiment of this invention. It is a schematic model diagram of the inverted two-wheeled robot according to the second embodiment of the present invention. It is a disassembled schematic diagram which shows schematic structure of the raising / lowering apparatus of the inverted two-wheeled robot concerning 2nd Embodiment of this invention. It is a schematic diagram which shows schematic structure of the raising / lowering apparatus of the inverted two-wheeled robot concerning 2nd Embodiment of this invention. It is a schematic flowchart which shows operation | movement of the inverted two-wheeled robot concerning 2nd Embodiment of this invention. It is a schematic flowchart which shows operation | movement of the inverted two-wheeled robot concerning 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each embodiment is simplified for convenience of explanation. Since the drawings are simple, the technical scope of the present invention should not be interpreted narrowly based on the drawings. The drawings are only for explaining the technical matters, and do not reflect the exact sizes or the like of the elements shown in the drawings. The same elements are denoted by the same reference numerals, and redundant description is omitted. Words indicating directions such as up, down, left, and right are used on the assumption that the drawing is viewed from the front.

[First Embodiment]
The first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic perspective view of an inverted two-wheeled robot. FIG. 2 is a schematic block diagram of an inverted two-wheeled robot. FIG. 3 is a schematic diagram of an inverted two-wheeled robot that moves on a flat surface. FIG. 4 is a schematic diagram of an inverted two-wheeled robot that moves on an inclined surface. FIG. 5 is a schematic explanatory diagram showing axes set for the inverted two-wheeled robot. FIG. 6 is an explanatory diagram showing a method of detecting an inclined surface of an inverted two-wheeled robot. FIG. 7 is an explanatory diagram illustrating a method of detecting the vehicle body tilt angle of the inverted two-wheeled robot. 8 and 9 are schematic bottom views of the inverted two-wheeled robot. FIG. 10 is an explanatory view showing the direction changing operation of the inverted two-wheeled robot. 11 and 12 are schematic flowcharts showing the operation of the inverted two-wheeled robot.

  As shown in FIG. 1, the inverted two-wheeled robot (moving body) 100 includes a main body portion 210 and a wheel portion 220. The main body part 210 includes a seat part 211, a pair of armrest parts 212, and a footrest part 213. A ball controller 215 is provided at the tip of the armrest 212. It is assumed that various electric / mechanical components such as various sensors, a microcomputer, a power supply, and a link mechanism are built in the main body 210.

  An occupant of the inverted two-wheeled robot 100 (hereinafter sometimes simply referred to as the robot 100) operates the ball controller 215 while sitting on the seat portion 211. The robot 100 operates according to the operation of the ball controller 215 by the passenger. For example, when the operator rotates the ball controller 215 forward, the robot 100 moves forward while maintaining the inverted state. Further, when the operator rotates the ball controller 215 to the right, the robot 100 rotates to the right while staying in the inverted position. In addition, the robot 100 shall be in an inverted state automatically according to the start switch switch-on by the passenger.

  The main body 210 is configured to be able to swing in the direction along the x axis (pitch direction) with respect to the wheel part 220. The main body 210 is not configured to be swingable in the direction along the y axis (roll direction) with respect to the wheel 220. Note that the z-axis direction shown in FIG. 1 coincides with the vertical direction.

  As shown in FIG. 2, the robot 100 includes an instruction input unit (input unit) 10, an acceleration detection unit (detection unit) 11, an angular velocity detection unit (detection unit) 12, a distance measurement unit (distance measurement unit) 13, and an encoder unit. (Detection means) 14, memory (storage means) 15, controller (signal generation means) 20, and drive unit (drive means) 30. The drive unit 30 includes an addition unit 31, a motor amplifier unit 32, a shunt resistor unit 33, a torque calculation unit 34, and a motor unit 35. It is assumed that a set of driving units 30 is provided corresponding to a set of wheels constituting the wheel unit 220.

  The robot 100 includes a digital value V0 output from the instruction input unit 10, a digital value V1 output from the acceleration detection unit 11, a digital value V2 output from the angular velocity detection unit 12, and a digital value output from the distance measurement unit 13. Based on V3 and the digital value V4 output from the encoder unit 14, the drive unit 30 (wheel unit 220) is driven to move in a desired direction while maintaining an inverted state, or to turn while staying there. . In the present embodiment, after the robot 100 is inverted, the angle in the pitch direction of the main body 210 with respect to the wheel 220 is corrected based on the measurement value of the distance measuring unit 13. By adopting this configuration, even if the road surface (grounding surface) is inclined, it is possible to effectively maintain the inclination of the main body 210 with respect to the wheel portion 220 and effectively prevent the passenger from feeling uneasy. it can.

  The instruction input unit 10 receives an operation instruction input from the operator of the robot 100 and generates a command value V0 corresponding to the input operation instruction. The command value V0 generated by the instruction input unit 10 is transmitted to the controller 20. The instruction input unit 10 corresponds to the ball controller 215 shown in FIG.

  The acceleration detection unit 11 detects acceleration in the x-axis and z-axis directions, and executes the following calculation formula to generate the tilt angle value V1.

V1 = Atan (Gx / Gz)
However, A is an arbitrary constant, Gx is acceleration in the x-axis direction, and Gz is acceleration in the z-axis direction.

  The acceleration detector 11 has an acceleration sensor corresponding to each axis. The output of the acceleration sensor is connected to a low-pass circuit. The output of the low-pass circuit is connected to the arithmetic circuit. The acceleration sensor is a sensor using MEMS (Micro-Electro Mechanical Systems). The low-pass circuit removes the high frequency component of the output waveform of the acceleration sensor and passes the low frequency component. The arithmetic circuit executes the above-described arithmetic expression based on the output of the low-pass circuit, and outputs the tilt angle value V1 obtained by the calculation. The tilt angle value V1 is a digital value indicating the tilt angle. One acceleration sensor is mounted with respect to the center of the main body 210. An acceleration sensor may be arranged at a position where the relative distance from the center of the main body 210 can be grasped.

  The angular velocity detector 12 detects and outputs the angular velocity of the main body 210 in the x-axis direction. Specifically, the angular velocity detector 12 detects the angular velocity with a gyro sensor and outputs it.

  The angular velocity detection unit 12 includes a mechanical type, a gas type, an optical type, and the like. The angular velocity detection unit 12 includes, for example, a gyro sensor using MEMS (Micro-Electro Mechanical Systems). A gyro sensor is manufactured by forming a three-dimensional structure with high definition on a substrate such as a semiconductor or glass by utilizing semiconductor process technology. The gyro sensor electrically detects the Coriolis force by electrically detecting the spatial displacement of the vibrating body disposed on the substrate. For example, the gyro sensor electrically detects the Coriolis force by placing the vibrating body in a vibrating state and detecting a change in capacitance value between the vibrating body and the detection electrode. The specific structure of the gyro sensor and the method for detecting the Coriolis force are arbitrary. The angular velocity value V <b> 2 is transmitted from the angular velocity detector 12 to the controller 20. The gyro sensor is mounted on the center of the main body 210 so as to correspond to the three axes of the X, Y, and Z axes.

  The distance measuring unit 13 measures the distance between the lower surface of the main body unit 210 and the road surface at a plurality of locations, and outputs the detected distance to the controller 20 as a distance value V3. The specific configuration of the distance measuring unit 13 is arbitrary. For example, the distance measuring unit 13 measures the distance by a TOF (Time Of Flight) method. The distance measuring unit 13 includes a plurality of distance measuring sensor units and a plurality of signal processing circuits. When the optical method is employed, the sensor unit is composed of a pair of a light emitting element and a light receiving element. The signal processing circuit calculates a distance by performing a predetermined calculation based on a time difference between the timing when the light emitting element is driven and the timing when the signal light is received by the light receiving element.

  The encoder unit 14 includes a set of encoder units associated with the set of wheel units 220. The encoder corresponding to the right wheel detects the relative rotation amount of the right wheel and outputs an encoder value (count value) V4 corresponding to the rotation amount. The same applies to the encoder corresponding to the left wheel. The specific configuration of the encoder is arbitrary. For example, either an optical or magnetic encoder may be employed. In the case of an optical encoder, the encoder optically detects the number of slits formed in the outer peripheral area of the rotating body provided on the wheel, and outputs a count value corresponding to the number of slits. In the case of a magnetic encoder, the encoder magnetically detects the number of magnets sequentially arranged in the outer peripheral area of the rotating body and outputs a count value corresponding to the number of magnets.

  The memory 15 is a general semiconductor memory and is connected to the controller 20. The memory 15 holds various setting values.

  The controller 20 controls the drive unit 30 based on the values V0 to V4. Specifically, the controller 20 generates a control value V10 based on the values V0 to V4 and outputs this to the drive unit 30. The controller 20 is realized by executing a program by a CPU (Central Processing Unit) or the like.

  The operation of the controller 20 will be described in detail with reference to the flowcharts shown in FIGS.

  The drive unit 30 drives the robot 100 based on the control value V10. Specifically, it is as follows.

  The adder 31 generates a command value V25 based on the control value V10 and the torque value V20. Digital values such as the control value V10 and the torque value V20 are added by the adding unit 31 to become the command value V25. The command value V25 corresponds to a difference value between the absolute value of the control value V10 and the absolute value of the torque value V20. The control value V10 is calculated ignoring the current torque generated in the motor unit 35. The intended torque can be generated by subtracting the torque value V20 having a value corresponding to the current torque generated in the motor unit 35 from the control value V10.

  The motor amplifier unit 32 generates a drive voltage having a value corresponding to the command value V25 and outputs it to the motor unit 35. Since the command value V25 is input continuously in time, a voltage waveform whose voltage value fluctuates in time is supplied from the motor amplifier unit 32 to the motor unit 35.

  The motor unit 35 generates power according to the input voltage waveform. The power generated by the motor unit 35 is supplied to the wheel unit 220.

  The torque calculation unit 34 calculates torque based on the current value detected by the shunt resistor unit 33 connected between the motor amplifier unit 32 and the motor unit 35. The torque calculator 34 outputs the calculated torque to the adder 31 as the torque value V20.

  As shown in FIG. 3, the robot 100 maintains an inverted state on a flat surface. As shown in FIG. 4, the robot 100 maintains an inverted state on the inclined surface. As shown in FIG. 3, the controller 20 generates a control value V <b> 10 for controlling the drive unit 30 so as to pull back the output value V <b> 2 of the angular velocity detection unit 12 with respect to the output value V <b> 1 of the acceleration detection unit 11. As shown in FIG. 4, the controller 20 generates a control value V <b> 10 for controlling the drive unit 30 so as to correct the inclination of the main body unit 210 in the pitch direction according to a flow described later.

  As shown in FIGS. 3 and 4, the sensor units 13 a and 13 b included in the distance measuring unit 13 are provided on the lower surface of the main body 210. In addition, the specific attachment method of sensor unit 13a, 13b with respect to the main-body part 210 is arbitrary.

  As shown in FIG. 5, in the movement space of the robot 100, an axis line X1 extending along the vertical direction and an axis line X3 orthogonal to the axis line X1 are set. In addition, the robot 100 is set with an axis X2 that is a natural axis of the robot 100 and an axis X4 that is orthogonal to the axis X2. The axis X2 is an axis that is orthogonal to a rotation axis common to a set of wheels that form the wheel portion 220.

  As described above, by driving the drive unit 30 so that the output value V2 of the angular velocity detection unit 12 is pulled back (matched) with the output value V1 of the acceleration detection unit 11, the axis line X4 matches the axis line X3. Thus, the robot 100 is controlled. In other words, similarly, the robot 100 is controlled so that the angle θ1 formed by the axis X3 and the axis X4 approaches zero.

  Similarly, by driving the drive unit 30, the robot 100 is controlled so that the axis X2 coincides with the axis X1. In other words, the robot 100 is controlled so that the angle θ2 formed by the axis X1 and the axis X2 approaches zero. In addition, not only the output value V2 of the angular velocity detection unit 12 but also the output value V1 of the acceleration detection unit 11 is taken into account for posture control so that the operation of the robot 100 can be stabilized.

  By the way, the output value of the acceleration detection unit 11 is affected by the accuracy of attaching the acceleration sensor to the main body unit 210, and there is a problem that the output value deteriorates with time due to wear of components in the acceleration sensor. Therefore, in order to control the posture of the robot 100 with high accuracy, it is necessary to correct the output value of the acceleration detector 11.

  Further, from the output value of the acceleration detection unit 11, it is impossible to distinguish the inclination of the road surface and the inclination of the main body part 210 with respect to the wheel part 220. Therefore, in the case shown in FIG. 4, controlling the drive unit 30 so as to pull back the output value V2 of the angular velocity detection unit 12 with respect to the output value V1 of the acceleration detection unit 11 destabilizes the behavior of the robot 100. It gives anxiety to the passengers on board 100.

  In the present embodiment, by performing posture control of the robot 100 based on the output value of the distance measuring unit 13, the posture of the robot 100 can be appropriately controlled even when the road surface is inclined. Accordingly, the robot 100 can be moved on an inclined surface while suppressing anxiety to the operator.

  As shown in FIG. 6, the distance measuring unit 13 detects the distance L1 between the sensor unit 13a and the road surface, and detects the distance L2 between the sensor unit 13b and the road surface. The controller 20 determines whether or not the road surface is inclined based on the distances L1 and L2 input as the distance value V3. If the difference value between the distance L1 and the distance L2 is a predetermined value or more, it can be determined that the road surface is inclined. Further, the controller 20 can calculate the inclination angle θ3 formed by the road surface with respect to the axis X3 based on the distances L1 and L2 input as the distance value V3. It is assumed that the interval between the sensor units 13a and 13b is known and stored in the memory 15.

  The controller 20 corrects the angle formed by the axis X2 with respect to the axis X1 based on the value calculated by the method described in FIG. For example, when the value of the inclination angle θ3 is larger than a predetermined value, it can be determined that the main body 210 is inclined forward too much. In this case, the controller 20 generates a control value V10 for controlling the drive unit 30 based on the output value V3 of the distance measurement unit 13 so that the value of the inclination angle θ3 becomes small. When the value of the inclination angle θ3 is smaller than the predetermined value, it can be determined that the main body 210 is inclined too much backward. In this case, the controller 20 generates a control value V10 for controlling the drive unit 30 based on the output value V3 of the distance measurement unit 13 so that the value of the inclination angle θ3 is increased.

  As shown in FIG. 7, the distance measuring unit 13 detects the distance L1 between the sensor unit 13a and the road surface, and detects the distance L2 between the sensor unit 13b and the road surface. The controller 20 calculates a difference value Δh between L1 and L2 (that is, executes Δh = L1−L2). Then, the controller 20 executes the following arithmetic expression. In this way, the controller 20 can calculate the vehicle body inclination angle (the angle formed by the axis X1 and the axis X2).

atan θ4 = | Δh | / L3
However, L3 is an arrangement interval between the sensor unit 13a and the sensor unit 13b.

  The output value of the acceleration detection unit 11 depends on the mounting accuracy of the acceleration sensor and may deteriorate with time. As shown in FIG. 7, by calculating the inclination angle of the axis X2 with respect to the axis X1 based on the output of the distance measuring unit 13, the output value V1 of the acceleration detecting unit 11 can be corrected. Specifically, the difference value between the angle value formed by the axis X1 and the axis X2 and the output value of the acceleration detection unit 11 may be stored in the memory 15 as a correction value. Then, it is preferable to correct the output value V2 of the angular velocity detection unit 12 using the correction value stored in the memory 15. As a result, the influence of the zero point deviation incorporated in the acceleration sensor is suppressed, and the robot 100 can control its posture with high accuracy.

  The number of sensor units included in the distance measuring unit 13 may be two or more, and the number is arbitrary. For example, as shown in FIG. 8, two sensor units may be arranged apart from each other along the x axis. Further, as shown in FIG. 9, two sets of two sensor units spaced along the x axis may be arranged along the y axis. As shown in FIG. 9, by disposing four sensor units, it is possible to increase resistance against failure of the sensor units.

  As shown in FIG. 9, the sensor units 13a and 13d are set as one set, and the sensor units 13b and 13c are set as a set, whereby the inclination in the xy plane can be detected. At this time, as shown in FIG. 10, the pitch direction of the robot 100 and the inclination direction of the road surface are made to coincide with each other by the turning function of the robot 100, and the main body 210 is inclined in the pitch direction in this state. Can be effectively increased, and the passenger can be effectively prevented from feeling uneasy.

  Next, the operation of the robot 100 will be described with reference to FIGS. 11 and 12. In this embodiment, the sensor unit is arranged as shown in FIG.

  First, the inversion control is started (S101). Specifically, the controller 20 determines, based on the output value V1 of the acceleration detection unit 11 and the output value V2 of the angular velocity detection unit 12, that the axis X2 that coincides with the natural axis of the robot 100 is relative to the axis X1 along the vertical direction. The control value V10 for controlling the drive unit 30 is generated so as to match.

  Next, a state value is acquired (S102). Specifically, the controller 20 acquires the output value V1 of the acceleration detection unit 11 and the output value V2 of the angular velocity detection unit 12 at a certain point in time. That is, a value (attitude value) indicating the posture of the robot obtained from the acceleration sensor and a value (attitude value) indicating the posture of the robot obtained from the gyro sensor are acquired.

  Next, it is determined whether or not the state value difference is within an allowable range (S103). Specifically, the controller 20 obtains a difference value between the acquired output value V1 and the output value V2, and determines whether the difference value is equal to or less than a predetermined value. When the difference between the state values is within the allowable range, the robot 100 performs the inversion control based on the output value V1 of the acceleration detection unit 11 and the output value V2 of the angular velocity detection unit 12.

  When the difference between the state values V1 and V2 is outside the allowable range, the distance between the lower surface of the vehicle body and the road surface is measured (S104). Specifically, the controller 20 instructs the distance measuring unit 13 to measure the distance. The distance measurement unit 13 measures the distances L1 and L2 between the main body unit 210 and the installation surface at a plurality of locations based on an instruction from the controller 20, and outputs the measured values to the controller 20.

  Next, it is determined whether or not the road surface is flat (S105). Specifically, the controller 20 determines whether or not the road surface is flat based on the distance value V3 transmitted from the distance measuring unit 13 by the method described with reference to FIG.

  If the road surface is not flat, an inclination correction process in the pitch direction is executed (S106). This step will be described with reference to FIG.

  If the road surface is flat, the acceleration sensor is calibrated (S107), a correction value is calculated and stored (S108). Specifically, the controller 20 calculates an angle θ2 formed by the axis X2 with respect to the axis X1 by the method described with reference to FIG. 5, and calculates a difference between the calculated angle and the output value V1 of the acceleration detection unit 11. This is obtained and stored in the memory 15 as an offset value. When the offset value is stored in the memory 15, the controller 20 corrects the output value of the acceleration detection unit 11 based on the offset value, and performs posture control based on the corrected value.

  Details of S106 will be described with reference to FIG.

  First, it is determined whether or not the tilt direction is the pitch direction (S110). Specifically, the controller 20 determines whether the slope direction of the road surface is the pitch direction based on the output value V3 of the distance measurement unit 13.

  If the slope direction of the road surface is not the pitch direction, the robot 100 turns 90 ° in the plane (S111). Specifically, the robot 100 turns as shown in FIG. Thereby, the pitch direction of the robot coincides with the inclination direction of the road surface.

  Next, the inclination is corrected by an angle θ in the pitch direction (S112). Specifically, the controller 20 generates a control value V10 for controlling the drive unit 30 so that the axis X2, which is the natural axis of the robot 100, is tilted by the designated angle θ. At the first time, the angle θ = 0 degrees is initially set. Therefore, no control is performed for the first time.

  Next, the distance between the lower surface of the vehicle body and the road surface is measured (S113). Specifically, the controller 20 instructs the distance measuring unit 13 to measure the distance. The distance measuring unit 13 measures the distance between the main body unit 210 and the installation surface at a plurality of locations based on an instruction from the controller 20, and outputs the measured value to the controller 20.

  Next, the inclination angle θ3 is calculated (S114). Specifically, the controller 20 calculates the tilt angle θ3 based on the output value V3 of the distance measuring unit 13 by the method described with reference to FIG.

  Next, it is determined whether or not the inclination angle θ3 is within an allowable range (S116). Specifically, the controller 20 determines whether or not the inclination angle θ3 is within the allowable range based on a comparison between the upper limit value and the lower limit value stored in advance in the memory 15 and the inclination angle θ3.

  If the inclination angle θ3 is within the allowable range, the process is terminated as it is.

  If the inclination angle θ3 is outside the allowable range, the angle is designated (S116). Specifically, the controller 20 reads the angle θ determined according to the value of the inclination angle θ3 from the memory 15, and designates the read value as the angle θ referred to in the correction process of S112. And it returns to above-mentioned step S112. In this S112, the angle θ is specified as a value read from the memory 15. Therefore, the controller 20 generates a control value V10 for controlling the drive unit 30 so that the axis X2 that is the natural axis of the robot 100 is inclined by the designated angle θ (value read from the memory 15). In this way, the axis line X2 is corrected so as to prevent the passenger from feeling uneasy based on the inclination of the road surface. After S116 and S112, S113 and S114 are performed in the same manner.

  If the tilt direction = pitch direction in S110, the process proceeds to S113. The flow shown in FIGS. 11 and 12 is executed in a very short cycle. Therefore, even when the robot 100 is moving at a relatively high speed, the posture control of the robot 100 can be appropriately performed according to the change in the inclination angle of the road surface. In addition, the turning operation of the robot 100 on the inclined surface can be stabilized.

  As is apparent from the above description, in this embodiment, the degree of road surface inclination is evaluated based on the output of the distance measuring unit 13, and the main body 210 of the robot 100 is moved in the pitch direction according to the evaluation result. Rotate to prevent the passenger from feeling uneasy. As a result, the robot 100 can be used on other than a flat surface, and the application range can be effectively expanded.

  In the present embodiment, the output of the angular velocity detection unit 12 can be corrected based on the output of the distance measurement unit 13. As a result, the error included in the output of the angular velocity detection unit 12 and its deterioration over time can be corrected, and the posture control of the robot 100 can be effectively enhanced. For example, when it is determined that the robot 100 is vertically inverted, it is possible to effectively avoid a situation in which the robot 100 is actually tilted.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a schematic block diagram of an inverted two-wheeled robot. FIG. 14 is a schematic diagram of an inverted two-wheeled robot. FIG. 15 is an exploded schematic view showing a schematic configuration of the lifting device of the inverted two-wheeled robot. FIG. 16 is a schematic diagram illustrating a schematic configuration of the lifting device of the inverted two-wheeled robot. FIG. 17 is a schematic flowchart showing the operation of the inverted two-wheeled robot. FIG. 18 is a schematic flowchart showing the operation of the inverted two-wheeled robot.

  In the present embodiment, in addition to the functions described in the first embodiment, the robot 100 is configured such that the relative position in the vertical direction between the main body 210 and the wheel 220 can be adjusted. Thus, even if the road surface is inclined in the roll direction (lateral direction), it is possible to effectively prevent the passenger from feeling uneasy by correcting the posture without turning the robot 100. can do. Also in this embodiment, the same effects as those described in the first embodiment can be obtained.

  As shown in FIG. 13, the robot 100 includes a drive unit 36. The drive unit 36 is controlled by the controller 20. When the elevating mechanism is driven by the drive unit 36, the interval in the vertical direction between the main body unit 210 and the wheel unit 220 is adjusted.

  As shown in FIG. 14, the robot 100 has an axis 240. The shaft 240 is composed of shafts 240a to 240c. The shaft 240a is a shaft member extending along the y-axis. The shafts 240b and 240c are shaft members that extend along the z-axis, and are connected to the respective ends of the shaft 240a.

  The wheel portion 220a is engaged with the shaft 240b so as to be movable up and down. The wheel portion 220a is variable on the shaft 240b in the z-axis direction. In other words, the relative position between the wheel portion 220a and the main body portion 210 in the z-axis direction is configured to be adjustable.

  The wheel portion 220b is movably engaged with the shaft 240c. The wheel part 220b is variable on the axis 240c in the z-axis direction. In other words, the relative position between the wheel portion 220a and the main body portion 210 in the z-axis direction is configured to be adjustable. In addition, the wheel part 220 is comprised by one set of wheel parts 220a and 220b.

  A specific mechanism for changing the distance between the wheel portion 220 and the main body portion 210 in the z-axis direction is arbitrary. For example, a mechanism as shown in FIGS. 15 and 16 may be employed.

  As shown in FIGS. 15 and 16, the wheel 50, the drive motor 51, the mount 52, the lead screw 53, and the drive motor 54 are arranged at the engagement portion between the wheel portion 220 a and the shaft 240 b. The wheel 50 is a general wheel. The drive motor 51 is connected to the wheels 50 via a rotation shaft. The wheel 50 rotates according to the rotational force generated by the drive motor 51. The mount 52 houses the drive motor 51. In addition, a groove that engages with the crest of the lead screw 53 is provided on the outer surface of the mount 52. The lead screw 53 is a member whose longitudinal direction is the z-axis, and a convex portion formed in a spiral shape is provided on the surface thereof. The drive motor 54 is connected to the lead screw 53. The mount 52 is displaced in the z-axis direction according to the rotational force generated by the drive motor 54. Along with the mount 52, the drive motor 51 and the wheel 50 are displaced in the z-axis direction. Note that the lead screw 53 coincides with the shaft 240b. The wheel unit 220 includes a wheel 50, a drive motor 51, and a mount 52.

  The operation of the robot 100 will be described with reference to FIGS. 17 and 18.

  As shown in FIG. 17, in the present embodiment, unlike the first embodiment, a roll direction inclination correction process (S120) is executed.

  With reference to FIG. 14, the roll direction inclination correction processing will be described with reference to FIG. It is assumed that the robot 100 is set in advance such that Δh = 0 based on the operator's command (command value V0).

  First, the current Δh is calculated (S131). Specifically, the controller 20 calculates Δh based on the output value V3 of the distance measuring unit 13 as described in FIG. More specifically, the controller 20 calculates L1−L2 = Δh.

  Next, the previously calculated Δh is read (S132). Specifically, the controller 20 reads the previously calculated Δh from the memory 15. Note that the controller 20 stores Δh in the memory 15 in accordance with a predetermined rule. For example, when the robot 100 is continuously moving on the inclined surface, Δh acquired five seconds ago is read in S132.

  Next, a difference value between the current Δh and the previous Δh is obtained (S133). Specifically, the controller 20 compares Δh calculated this time with Δh read from the memory 15 and obtains a difference value therebetween.

  Next, it is determined whether or not the difference value is within a predetermined range (S134). Specifically, it is determined whether or not the difference value obtained in S133 is within a predetermined range. Note that the upper limit value and the lower limit value are stored in advance in the memory 15, and the controller 20 reads these values from the memory 15 and compares them with the difference values to determine whether or not the difference values are within a predetermined range. It is good to judge.

  If the difference value is within the predetermined range, the process is terminated. In this case, it can be determined that there is little change in the slope of the road surface.

  If the difference value is out of the predetermined range, the lifting / lowering operation is executed (S135). Specifically, the controller 20 generates a control value V30 for controlling the drive unit 36 so as to improve the stability of the robot 100 according to the value of the difference value. Then, the drive unit 36 drives the drive motor 54 shown in FIGS. 15 and 16 according to the control value V30, rotates the lead screw 53, and displaces the mount 52 in the z-axis direction. Thereby, the wheel 50 is displaced along the z axis, and the arrangement interval between the wheel 50 and the main body 210 is changed. Accordingly, for example, as shown in FIG. 14, the wheel portion 220 b can be moved to the main body portion 210 side in accordance with the inclination state of the road surface, and the stability of the robot 100 in the roll direction can be enhanced while being on the spot. .

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. The specific configuration of the robot 100 is arbitrary. The functions of the robot 100 may be realized by software or hardware.

100 Inverted two-wheeled robot

210 Body 211 Seat 212 Armrest 213 Footrest 215 Ball Controller 220 Wheel 240 Shaft

DESCRIPTION OF SYMBOLS 10 Instruction input part 11 Acceleration detection part 12 Angular velocity detection part 13 Distance measurement part 14 Encoder part 15 Memory 20 Controller 30 Drive part 31 Adder part 32 Motor amplifier part 33 Shunt resistance part 34 Torque calculation part 35 Motor part 36 Drive part


V0 Command value V1 Inclination angle value V2 Angular velocity value V3 Distance value V10 Control value V20 Torque value V25 Command value V30 Control value

Claims (7)

A main body is rotatably connected to a wheel portion, and a moving body that moves in space in an inverted state in which the main body portion is inverted with respect to the wheel portion according to driving of the wheel portion,
When the moving body is in an inverted state, measure the distance between the grounding surface on which the wheel unit is grounded and the main body at a plurality of locations,
The flatness of the ground contact surface is evaluated based on the measurement result, and the movable body in an inverted state is controlled by controlling the relative position between the wheel portion and the main body portion according to the flatness evaluation result of the ground contact surface. A moving body that controls the posture of the body.   2. The posture of the movable body in an inverted state is controlled by rotating the main body with respect to the wheel portion according to an evaluation result of flatness of the ground surface. Moving body.   The posture of the mobile body in an inverted state is controlled by controlling the relative position between the wheel part and the main body part along an axis intersecting the grounding surface according to the evaluation result of the flatness of the grounding surface. The moving body according to claim 1, wherein the moving body is controlled. First detecting means for detecting an angular velocity of the main body part with respect to the wheel part;
When the main body is in an inverted state with respect to the wheel portion, distance measuring means for measuring a distance between the ground surface on which the wheel portion is grounded and the main body portion;
A signal for controlling the posture of the robot is generated according to at least the angular velocity detected by the first detection unit, and the posture of the robot in an inverted state is corrected based on a measurement value by the distance measurement unit. Signal generating means for generating a signal for
The moving body according to any one of claims 1 to 3, further comprising:   The mobile body according to claim 4, wherein the first detection unit includes a gyro sensor manufactured by utilizing MEMS technology. A second detector for detecting the acceleration of the main body in a plurality of directions and calculating an angle formed by the natural axis of the robot with respect to the vertical direction based on the detected acceleration;
The moving body according to claim 4 or 5, wherein the signal generation unit generates a signal for controlling the posture of the robot based on output values of the first and second detection units.   The moving body according to claim 6, wherein the angle calculated by the second detection unit is corrected based on a measurement value of the distance measurement unit.

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