JP5330199B2 - Control device for inverted pendulum type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of an inverted-pendulum type vehicle in which the limit of a constitution of a moving operation part detectible in idling is reduced, and which can perform idling detection reduced in the limit of detectible idling. <P>SOLUTION: A control unit 50 calculates a floor reaction force F acting on a vehicle 1 from a measurement value &theta;bdot_xy_s of an inclination angular velocity of a base body 9 and an estimation value Vb_xy of center velocity of the vehicle 1, and calculates torque T which needs to be given to a wheel body 5 when the calculated floor reaction force F is generated. Furthermore, the control unit 50 estimates the torque T which regulates a target value of a determined control operation quantity. Furthermore, the control unit 50 detects the generation of idling of the wheel body 5 based on a difference of the torque T. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a control device for an inverted pendulum type vehicle that can move on a floor surface.

  The inverted pendulum type vehicle has a base that is assembled with a moving operation unit that moves on the floor and an actuator device that drives the moving operation unit. In order to keep the inclination angle of the riding section at a certain target angle (in order to prevent the riding section from tilting), the moving operation unit is moved in such a manner that the fulcrum of the inverted pendulum is moved. It is a vehicle that needs to be moved.

  As a control technique for this type of inverted pendulum type vehicle, for example, the one shown in Patent Document 1 has been proposed by the present applicant.

  In this Patent Document 1, a vehicle base body on which a passenger's riding section is assembled is provided so as to be tiltable about two axes, a longitudinal axis and a lateral axis, with respect to a spherical moving operation unit. A control technique for the inverted inverted pendulum type vehicle is described. In this technology, the measured value of the inclination angle of the riding section (the inclination angle around the two axes in the front-rear direction and the left-right direction) is converged to the required target inclination angle, and the moving speed in the front-rear direction and the left-right direction of the vehicle is measured. The torque command value of the electric motor as an actuator is determined so that the value converges to the target speed, and the operation of the electric motor is controlled according to this torque command value, so that the vehicle is moved.

  In addition, as a vehicle that can function as an inverted pendulum type vehicle, those shown in Patent Documents 2 and 3 have been proposed by the applicant of the present application.

  Patent Document 4 describes a vehicle that detects the occurrence of slip between a wheel and a road surface. This vehicle includes a pair of left and right wheels at a lower portion of a vehicle body that includes a seat and can swing in the front-rear direction. Then, the predicted value of the turning angular velocity of the moving body calculated from the actual measurement values of the rotational angular velocities of the left and right wheels is compared with the actual measurement value of the turning angular velocity of the moving body to detect the occurrence of slip.

Patent No.3070015 PCT International Publication WO / 2008/132778 PCT International Publication WO / 2008/127279 JP 2008-189089 A

  However, in slip detection (idling detection) described in Patent Document 4, only slip of a vehicle in which a plurality of wheels are arranged so that a line connecting the axis of the wheels is not parallel to the traveling direction is detected. This is not possible, and the configuration of the moving operation unit capable of detecting slip is limited. Moreover, only slip at the time of turning can be detected, for example, slip at the time of going straight cannot be detected, and the idling that can be detected is limited.

  The present invention has been made in view of such a background, and the control of an inverted pendulum type vehicle capable of performing idling detection with few limitations on the configuration of the moving operation unit capable of detecting idling and having few limitations on idling that can be detected. An object is to provide an apparatus.

  In order to achieve such an object, a control device for an inverted pendulum type vehicle according to the present invention includes a moving operation unit that can move on a floor surface, an actuator device that drives the moving operation unit, and the moving operation unit and actuator device. Is an inverted pendulum type vehicle control device comprising a base body assembled with the base body and a tilting part assembled to the base body so as to be tiltable with respect to a vertical direction. A target value of the control operation amount that defines the driving force applied to the movement operation unit is determined, and the movement operation of the movement operation unit is controlled via the actuator device according to the determined target value of the control operation amount. The floor reaction force acting on the vehicle is calculated from the observed movement amount related to the tilting portion of the tilting portion and the state quantity related to the moving motion of the tilting portion, and the calculated floor reaction force is generated. and when Driving force calculating means for calculating a driving force that needs to be applied to the moving operation section, and driving force estimating means for estimating the driving force that defines the target value of the control operation amount determined by the moving section control means And idling detection means for detecting the occurrence of idling of the moving operation unit based on the driving force calculated by the driving force calculation means and the driving force estimated by the driving force estimation means.

  In the present invention, “floor” does not mean a floor in a normal sense (such as an indoor floor) but also includes an outdoor ground or road surface.

  According to the present invention, the driving force calculating means calculates the floor reaction force acting on the vehicle from the observation amount related to the tilt posture of the tilting portion and the state amount related to the moving motion of the moving operation portion, and the calculated floor reaction force is calculated. The driving force that needs to be applied to the moving operation unit when it occurs is calculated. On the other hand, the driving force estimation means estimates the driving force that defines the target value of the control operation amount determined by the moving unit control means. The idling detection means detects the occurrence of idling in the moving operation unit based on the driving force calculated by the driving force calculation means and the driving force estimated by the driving force estimation means.

  If the movement operation unit is moving as intended by the movement operation control unit, there is no difference between the driving force calculated by the driving force calculation unit and the driving force estimated by the driving force estimation unit. However, when idling occurs in the movement operation unit, the movement operation unit does not move as intended by the movement operation control unit, and the driving force calculated by the driving force calculation unit and the driving estimated by the driving force estimation unit There is a difference between force. Therefore, based on the driving force calculated by the driving force calculation unit and the driving force estimated by the driving force estimation unit, it is possible to determine the possibility that the idling has occurred in the moving operation unit. Therefore, it is possible to detect the occurrence of idling of the moving operation unit based on at least the driving force calculated by the driving force calculation unit and the driving force estimated by the driving force estimation unit.

  Unlike the slip detection described in Patent Document 4, it is possible to determine the possibility of idling regardless of the configuration of the moving operation unit. Furthermore, since it is possible to detect the possibility that idling has occurred in the moving operation unit that affects the tilting angular velocity of the tilting unit, it is possible to detect idling during straight traveling as well as during turning.

  In the present invention, when the idling detection means detects the occurrence of idling of the moving operation unit, the moving unit control means preferably causes the control operation amount to be closer to “0” than the basic target value.

  In this case, when the idling detection means detects the occurrence of idling in the moving operation unit, it is easier to eliminate idling than to maintain the control operation amount at the basic target value.

  By the way, it is difficult to eliminate idling as the tilt angle of the tilting portion increases.

  Therefore, the observation amount related to the tilt posture of the tilting portion includes at least the observation amount of the tilt angle of the tilting portion, and the moving operation unit control means increases the observation amount of the tilt angle of the tilting portion as the control amount. It is preferable to determine the target value of the control operation amount so that the ratio of approaching the basic target value of the operation amount to “0” increases.

  Further, in the present invention, the moving operation unit is configured to be movable in all directions including a first direction and a second direction orthogonal to each other on the floor surface, and the tilting unit is configured to move the first moving unit. The idle rotation detecting means is attached to the base body so as to be tiltable about two axes, ie, a direction axis and a second direction axis, and the idling detection means includes the driving force calculated by the driving force calculation means and the driving force. The reference for detecting the occurrence of idling of the moving operation unit based on the driving force estimated by the estimating unit is different between the first direction and the second direction, and the moving operation unit control unit includes: In order to move the moving operation unit in the first direction, a first control operation amount that defines a driving force applied to the moving operation unit and the moving operation unit to move in the second direction. A second control operation amount that regulates the driving force applied to the moving operation unit. Sequentially determined, it is preferable to control the movement of the moving operation part depending on the set of the thus determined first control operation amount and the second control operation amount.

  In this case, the idling detection sensitivity in the first direction is different from that in the second direction. Therefore, by increasing the detection sensitivity in the direction where it is difficult to eliminate idling or in the direction where the influence of idling is large, idling in that direction can be detected earlier, and problems caused by idling can be further suppressed.

The front view of the inverted pendulum type vehicle of embodiment. The side view of the inverted pendulum type vehicle of embodiment. The figure which expands and shows the lower part of the inverted pendulum type vehicle of embodiment. The perspective view of the lower part of the inverted pendulum type vehicle of embodiment. The perspective view of the movement operation part (wheel body) of the inverted pendulum type vehicle of embodiment. The figure which shows the arrangement | positioning relationship between the movement operation part (wheel body) and free roller of the inverted pendulum type vehicle of embodiment. The flowchart which shows the process of the control unit of the inverted pendulum type vehicle of embodiment. The figure which shows the inverted pendulum model expressing the dynamic behavior of the inverted pendulum type vehicle of embodiment. FIG. 8 is a block diagram showing processing functions related to STEP 9 in FIG. 7. The block diagram which shows the processing function of the gain adjustment part shown in FIG. The block diagram which shows the processing function of the limit process part (or limit process part shown in FIG. 12) shown in FIG. The block diagram which shows the processing function of the gravity center speed restriction | limiting part 76 shown in FIG. The block diagram which shows the processing function of the attitude | position control calculating part 80 shown in FIG. The flowchart which shows the process of the idling suppression part 81 shown in FIG. The flowchart which shows the subroutine processing of STEP24 of FIG. The flowchart which shows the subroutine processing of STEP25 of FIG.

  One embodiment of the present invention will be described below. First, the structure of an inverted pendulum type vehicle in the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, an inverted pendulum type vehicle 1 (hereinafter simply referred to as a vehicle 1) in the present embodiment includes a passenger (driver) riding section 3 as a transport target object of the vehicle 1, and a floor A moving operation unit 5 capable of moving in all directions (two-dimensional all directions including the front-rear direction being the first direction and the left-right direction being the second direction) on the floor surface while being in contact with the surface, An actuator device 7 that applies power for driving the moving operation unit 5 to the moving operation unit 5, and a base 9 on which the riding unit 3, the moving operation unit 5, and the actuator device 7 are assembled. The riding section 3 is a tilting section that can tilt with respect to the vertical direction.

  Here, in the description of the present embodiment, “front-rear direction” and “left-right direction” respectively match or substantially coincide with the front-rear direction and the left-right direction of the upper body of the occupant who has boarded the riding section 3 in a standard posture. Means direction. Note that the “standard posture” is a posture assumed by design with respect to the riding section 3, and the trunk axis of the occupant's upper body is generally directed vertically and the upper body is not twisted. It is posture.

  In this case, in FIG. 1, the “front-rear direction” and the “left-right direction” are the direction perpendicular to the paper surface and the left-right direction of the paper surface, respectively. In FIG. It is the left-right direction of the paper surface and the direction perpendicular to the paper surface. In the description of the present embodiment, the suffixes “R” and “L” attached to the reference numerals are used to mean the right side and the left side of the vehicle 1, respectively.

  The base 9 includes a lower frame 11 in which the moving operation unit 5 and the actuator device 7 are assembled, and a support frame 13 extending upward from the upper end of the lower frame 11.

  A seat frame 15 projecting forward from the column frame 13 is fixed to the upper portion of the column frame 13. A seat 3 on which an occupant sits is mounted on the seat frame 15. In the present embodiment, the seat 3 is a passenger's riding part (tilting part). Therefore, the inverted pendulum type vehicle 1 according to the present embodiment moves on the floor surface with the occupant seated on the seat 3.

  Further, on the left and right sides of the seat 3, grips 17R and 17L are disposed for the passengers seated on the seat 3 to grip as necessary. These grips 17R and 17L are respectively provided to the support frame 13 (or the seat frame 15). It is being fixed to the front-end | tip part of bracket 19R, 19L extended from.

  The lower frame 11 includes a pair of cover members 21R and 21L arranged so as to face each other in a bifurcated manner with a space in the left-right direction. The upper end portions (bifurcated branch portions) of these cover members 21R and 21L are connected via a hinge shaft 23 having a longitudinal axis, and one of the cover members 21R and 21L is hinged relative to the other. It can swing around the shaft 23. In this case, the cover members 21R and 21L are urged by a spring (not shown) in a direction in which the lower end side (the bifurcated tip side) of the cover members 21R and 21L is narrowed.

  Further, on each outer surface portion of the cover members 21R and 21L, a step 25R for placing the right foot of the occupant seated on the seat 3 and a step 25L for placing the left foot are respectively projected so as to protrude rightward and leftward. Yes.

  The moving operation unit 5 and the actuator device 7 are disposed between the cover members 21R and 21L of the lower frame 11. The structures of the moving operation unit 5 and the actuator device 7 will be described with reference to FIGS.

  The moving operation unit 5 and the actuator device 7 exemplified in the present embodiment have the same structure as that disclosed in FIG. Therefore, in the description of the present embodiment, the matters described in Patent Document 2 regarding the configurations of the moving operation unit 5 and the actuator device 7 are simply described.

  In the present embodiment, the moving operation unit 5 is a wheel body formed in an annular shape from a rubber-like elastic material, and has a substantially circular cross-sectional shape. Due to its elastic deformation, the moving operation unit 5 (hereinafter referred to as the wheel body 5) has a circular cross section center C1 (more specifically, a circular cross section center C1 as shown by an arrow Y1 in FIGS. 5 and 6). And can be rotated around a circumferential line that is concentric with the axis of the wheel body 5.

  The wheel body 5 is disposed between the cover members 21R and 21L with its axis C2 (axis C2 orthogonal to the diameter direction of the entire wheel body 5) directed in the left-right direction. Ground to the floor at the lower end of the outer peripheral surface.

  The wheel body 5 rotates around the axis C2 of the wheel body 5 as shown by an arrow Y2 in FIG. 5 (operation to rotate on the floor surface) by driving by the actuator device 7 (details will be described later). And an operation of rotating around the cross-sectional center C1 of the wheel body 5 can be performed. As a result, the wheel body 5 can move in all directions on the floor surface by a combined operation of these rotational operations.

  The actuator device 7 includes a rotating member 27R and a free roller 29R interposed between the wheel body 5 and the right cover member 21R, and a rotating member interposed between the wheel body 5 and the left cover member 17L. 27L and a free roller 29L, an electric motor 31R as an actuator disposed above the rotating member 27R and the free roller 29R, and an electric motor 31L as an actuator disposed above the rotating member 27L and the free roller 29L. .

  The electric motors 31R and 31L have their respective housings attached to the cover members 21R and 21L. Although illustration is omitted, the power sources (capacitors) of the electric motors 31 </ b> R and 31 </ b> L are mounted at appropriate positions on the base 9 such as the support frame 13.

  The rotating member 27R is rotatably supported by the cover member 21R via a support shaft 33R having a horizontal axis. Similarly, the rotation member 27L is rotatably supported by the cover member 21L via a support shaft 33L having a horizontal axis. In this case, the rotation axis of the rotation member 27R (axis of the support shaft 33R) and the rotation axis of the rotation member 27L (axis of the support shaft 33L) are coaxial.

  The rotating members 27R and 27L are connected to the output shafts of the electric motors 31R and 31L via power transmission mechanisms including functions as speed reducers, respectively, and the power (torque) transmitted from the electric motors 31R and 31L, respectively. It is rotationally driven by. Each power transmission mechanism is of a pulley-belt type, for example. That is, as shown in FIG. 3, the rotating member 27R is connected to the output shaft of the electric motor 31R via the pulley 35R and the belt 37R. Similarly, the rotating member 27L is connected to the output shaft of the electric motor 31L via a pulley 35L and a belt 37L.

  The power transmission mechanism may be constituted by, for example, a sprocket and a link chain, or may be constituted by a plurality of gears. In addition, for example, the electric motors 31R and 31L are arranged to face the rotating members 27R and 27L so that the respective output shafts are coaxial with the rotating members 27R and 27L, and the electric motors 31R and 31L are respectively arranged. The output shaft may be connected to each of the rotating members 27R and 27L via a speed reducer (such as a planetary gear device).

  Each rotating member 27R, 27L is formed in the same shape as a truncated cone that decreases in diameter toward the wheel body 5, and its outer peripheral surface is a tapered outer peripheral surface 39R, 39L.

  A plurality of free rollers 29R are arranged around the tapered outer peripheral surface 39R of the rotating member 27R so as to be arranged at equal intervals on a circumference concentric with the rotating member 27R. Each of these free rollers 29R is attached to the tapered outer peripheral surface 39R via a bracket 41R and is rotatably supported by the bracket 41R.

  Similarly, a plurality (the same number as the free rollers 29R) of free rollers 29L are arranged around the tapered outer peripheral surface 39L of the rotating member 27L so as to be arranged at equal intervals on a circumference concentric with the rotating member 27L. Yes. Each of these free rollers 29L is attached to the taper outer peripheral surface 39L via the bracket 41L, and is rotatably supported by the bracket 41L.

  The wheel body 5 is disposed coaxially with the rotating members 27R and 27L so as to be sandwiched between the free roller 29R on the rotating member 27R side and the free roller 29L on the rotating member 27L side.

  In this case, as shown in FIGS. 1 and 6, each of the free rollers 29 </ b> R and 29 </ b> L has the axis C <b> 3 inclined with respect to the axis C <b> 2 of the wheel body 5 and the diameter direction of the wheel body 5 (the wheel body 5. When viewed in the direction of the axis C2, it is arranged in a posture inclined with respect to the radial direction connecting the axis C2 and the free rollers 29R and 29L. In such a posture, the outer peripheral surfaces of the free rollers 29R and 29L are in pressure contact with the inner peripheral surface of the wheel body 5 in an oblique direction.

  More generally speaking, the free roller 29R on the right side has a frictional force component in the direction around the axis C2 at the contact surface with the wheel body 5 when the rotating member 27R is driven to rotate around the axis C2. (The frictional force component in the tangential direction of the inner periphery of the wheel body 5) and the frictional force component in the direction around the cross-sectional center C1 of the wheel body 5 (the tangential frictional force component in the circular cross section) The wheel body 5 is pressed against the inner peripheral surface in such a posture that it can act on the wheel body 5. The same applies to the left free roller 29L.

  In this case, as described above, the cover members 21R and 21L are urged in a direction in which the lower end side (the bifurcated tip side) of the cover members 21R and 21L is narrowed by a spring (not shown). Therefore, the wheel body 5 is sandwiched between the right free roller 29R and the left free roller 29L by this urging force, and the free rollers 29R and 29L are in pressure contact with the wheel body 5 (more specifically, free The pressure contact state in which a frictional force can act between the rollers 29R and 29L and the wheel body 5 is maintained.

  In the vehicle 1 having the structure described above, when the rotating members 27R and 27L are driven to rotate at the same speed in the same direction by the electric motors 31R and 31L, the wheel body 5 has the same direction as the rotating members 27R and 27L. Will rotate around the axis C2. Thereby, the wheel body 5 rotates on the floor surface in the front-rear direction, and the entire vehicle 1 moves in the front-rear direction. In this case, the wheel body 5 does not rotate around the center C1 of the cross section.

  Further, for example, when the rotating members 27R and 27L are rotationally driven in opposite directions at the same speed, the wheel body 5 rotates around the center C1 of the cross section. As a result, the wheel body 4 moves in the direction of the axis C2 (that is, the left-right direction), and as a result, the entire vehicle 1 moves in the left-right direction. In this case, the wheel body 5 does not rotate around the axis C2.

  Furthermore, when the rotating members 27R and 27L are rotationally driven at different speeds (speeds including directions) in the same direction or in the opposite direction, the wheel body 5 rotates around its axis C2, It will rotate about the cross-sectional center C1.

  At this time, the wheel body 5 moves in a direction inclined with respect to the front-rear direction and the left-right direction by a combined operation (composite operation) of these rotational operations, and as a result, the entire vehicle 1 moves in the same direction as the wheel body 5. Will be. The moving direction of the wheel body 5 in this case changes depending on the difference in rotational speed (rotational speed vector in which the polarity is defined according to the rotational direction) including the rotational direction of the rotating members 27R and 27L. .

  Since the moving operation of the wheel body 5 is performed as described above, by controlling the respective rotational speeds (including the rotational direction) of the electric motors 31R and 31L, and by controlling the rotational speeds of the rotating members 27R and 27L, The moving speed and moving direction of the vehicle 1 can be controlled.

  The seat (boarding portion) 3 and the base body 9 are tiltable about the axis C2 in the left-right direction with the axis C2 of the wheel body 5 as a fulcrum, and the grounding surface (lower end surface) of the wheel body 5 As a fulcrum, it can be tilted together with the wheel body 5 around an axis in the front-rear direction.

  Next, the structure for operation control of the vehicle 1 of this embodiment is demonstrated. In the following description, as shown in FIGS. 1 and 2, an XYZ coordinate system is assumed in which the horizontal axis in the front-rear direction is the X axis, the horizontal axis in the left-right direction is the Y axis, and the vertical direction is the Z axis. The direction and the left-right direction may be referred to as the X-axis direction and the Y-axis direction, respectively.

  First, schematic operation control of the vehicle 1 will be described. In the present embodiment, basically, when an occupant seated on the seat 3 tilts its upper body (specifically, the occupant and the vehicle 1 are combined). When the upper body is tilted so as to move the position of the entire center of gravity (the position projected on the horizontal plane), the base body 9 tilts together with the sheet 3 to the side on which the upper body is tilted. At this time, the moving operation of the wheel body 5 is controlled so that the vehicle 1 moves to the side on which the base body 9 is inclined. For example, when the occupant tilts the upper body forward and, as a result, tilts the base body 9 together with the seat 3, the movement operation of the wheel body 5 is controlled so that the vehicle 1 moves forward.

  That is, in the present embodiment, the operation of the occupant moving the upper body and thus tilting the base body 9 together with the seat 3 is one basic control operation (operation request of the vehicle 1) for the vehicle 1, and the control The moving operation of the wheel body 5 is controlled via the actuator device 7 in accordance with the operation.

  Here, in the vehicle 1 of the present embodiment, the ground contact surface of the wheel body 5 as the entire ground contact surface has an area compared to a region where the entire vehicle 1 and the passengers riding on the vehicle 1 are projected on the floor surface. It becomes a small single local region, and the floor reaction force acts only on the single local region. For this reason, in order to prevent the base body 9 from tilting, it is necessary to move the wheel body 5 so that the center of gravity of the occupant and the vehicle 1 is positioned almost directly above the ground contact surface of the wheel body 5.

  Therefore, in the present embodiment, the center of gravity of the entire occupant and vehicle 1 is positioned almost directly above the center point of the wheel body 5 (center point on the axis C2) (more precisely, the center of gravity point is The posture of the base body 9 in a state (which is located almost directly above the ground contact surface of the wheel body 5) is set as a target posture, and basically, the actual posture of the base body 9 is converged to the target posture. The movement operation is controlled.

  Further, in a state where no occupant is on board the vehicle 1, a state where the center of gravity of the single vehicle 1 is located almost directly above the center point of the wheel body 5 (center point on the axis C <b> 2) (more accurately, (The state where the center of gravity is located almost directly above the ground contact surface of the wheel body 5) is the target posture, and the actual posture of the base 9 is converged to the target posture. The movement operation of the wheel body 5 is controlled so that the vehicle 1 can stand on its own without tilting.

  In addition, in both the state where the occupant is on board the vehicle 1 and the state where the occupant is not on board, the moving speed of the vehicle 1 increases as the deviation from the target posture of the base body 9 increases. In a state where the actual posture of the base body 9 coincides with the target posture, the moving operation of the wheel body 5 is controlled so that the movement of the vehicle 1 is stopped.

  Supplementally, “posture” means a spatial orientation. In the present embodiment, the base body 9 and the sheet 3 are tilted to change the postures of the base body 9 and the sheet 3. Further, in the present embodiment, the base body 9 and the sheet 3 are integrally tilted, so that the posture of the base body 9 is converged to the target posture, which means that the posture of the sheet 3 is the target posture corresponding to the seat 3 ( This is equivalent to converging to the posture of the sheet 3 in a state where the posture of the base 9 matches the target posture of the base 9.

  In the present embodiment, in order to control the operation of the vehicle 1 as described above, as shown in FIG. 1 and FIG. 2, it is constituted by an electronic circuit unit including a microcomputer and drive circuit units of the electric motors 31R and 31L. An occupant gets on the control unit 50, an inclination sensor 52 for measuring an inclination angle θb of the predetermined portion of the base body 9 with respect to the vertical direction (gravity direction) and its changing speed (= dθb / dt), and the vehicle 1 A load sensor 54 for detecting whether or not the vehicle is rotating, and rotary encoders 56R and 56L as angle sensors for detecting the rotational angles and rotational angular velocities of the output shafts of the electric motors 31R and 31L, respectively. Installed in place.

  In this case, the control unit 50 and the inclination sensor 52 are attached to the column frame 13 in a state of being accommodated in the column frame 13 of the base body 9, for example. The load sensor 54 is built in the seat 3. The rotary encoders 56R and 56L are provided integrally with the electric motors 31R and 31L, respectively. The rotary encoders 56R and 56L may be attached to the rotating members 27R and 27L, respectively.

  More specifically, the tilt sensor 52 includes an acceleration sensor and a rate sensor (angular velocity sensor) such as a gyro sensor, and outputs detection signals of these sensors to the control unit 50. Then, the control unit 50 performs a predetermined measurement calculation process (this may be a known calculation process) based on the outputs of the acceleration sensor and the rate sensor of the tilt sensor 52, and thereby the part on which the tilt sensor 52 is mounted. The measured value of the inclination angle θb with respect to the vertical direction (the column frame 13 in this embodiment) and the measured value of the inclination angular velocity θbdot, which is the change speed (differential value) thereof, are calculated.

  In this case, the tilt angle θb to be measured (hereinafter also referred to as the base body tilt angle θb) is more specifically, the component θb_x in the Y axis direction (pitch direction) and the X axis direction (roll direction), respectively. It consists of component θb_y. Similarly, the measured tilt angular velocity θbdot (hereinafter also referred to as the base tilt angular velocity θbdot) is also measured in the Y-axis direction (pitch direction) component θbdot_x (= dθb_x / dt) and the X-axis direction (roll direction). Component θbdot_y (= dθb_y / dt).

  Supplementally, in the present embodiment, since the seat 3 tilts integrally with the support frame 13 of the base body 9, the base body tilt angle θb also has a meaning as the tilt angle of the riding section 3.

  In the description of the present embodiment, a variable such as a motion state quantity having a component in each direction of the X axis and the Y axis (or a direction around each axis) such as the base body inclination angle θb, or a relation to the motion state quantity. For a variable such as a coefficient to be processed, a suffix “_x” or “_y” is added to the reference symbol of the variable when each component is expressed separately.

  In this case, for a variable related to translational motion such as translational speed, a subscript “_x” is added to the component in the X-axis direction, and a subscript “_y” is added to the component in the Y-axis direction.

  On the other hand, for variables related to rotational motion, such as angle, rotational speed (angular velocity), angular acceleration, etc., the subscript “_x” is added to the component around the Y axis for convenience in order to align the subscript with the variable related to translational motion. In addition, the subscript “_y” is added to the component around the X axis.

  Further, when a variable is expressed as a set of a component in the X-axis direction (or a component around the Y-axis) and a component in the Y-axis direction (or a component around the X-axis), the reference numeral of the variable The subscript “_xy” is added. For example, when the base body tilt angle θb is expressed as a set of a component θb_x around the Y axis and a component θb_y around the X axis, it is expressed as “base body tilt angle θb_xy”.

  The load sensor 54 is built in the seat 3 so as to receive a load due to the weight of the occupant when the occupant sits on the seat 3, and outputs a detection signal corresponding to the load to the control unit 50. Then, the control unit 50 determines whether or not an occupant is on the vehicle 1 based on the measured load value indicated by the output of the load sensor 54.

  Instead of the load sensor 54, for example, a switch type sensor that is turned on when an occupant sits on the seat 3 may be used.

  The rotary encoder 56 </ b> R generates a pulse signal each time the output shaft of the electric motor 31 </ b> R rotates by a predetermined angle, and outputs this pulse signal to the control unit 50. Then, the control unit 50 measures the rotational angle of the output shaft of the electric motor 53R based on the pulse signal, and further calculates the temporal change rate (differential value) of the measured value of the rotational angle as the rotational angular velocity of the electric motor 53R. Measure as The same applies to the rotary encoder 56L on the electric motor 31L side.

  The control unit 50 determines a speed command that is a target value of the rotational angular speed of each of the electric motors 31R and 31L by executing a predetermined calculation process using each of the measured values, and the electric motor is operated according to the speed command. The rotational angular velocities of the motors 31R and 31L are feedback controlled.

  The relationship between the rotational angular velocity of the output shaft of the electric motor 31R and the rotational angular velocity of the rotating member 27R is proportional to the constant reduction ratio between the output shaft and the rotating member 27R. In the description of this embodiment, for the sake of convenience, the rotational angular velocity of the electric motor 31R means the rotational angular velocity of the rotating member 27R. Similarly, the rotational angular velocity of the electric motor 31L means the rotational angular velocity of the rotating member 27L.

  Hereinafter, the control process of the control unit 50 will be described in more detail.

  The control unit 50 executes the process (main routine process) shown in the flowchart of FIG. 7 at a predetermined control process cycle.

  First, in STEP 1, the control unit 50 acquires the output of the tilt sensor 52.

  Next, proceeding to STEP 2, the control unit 50 calculates the measured value θb_xy_s of the base body tilt angle θb and the measured value θbdot_xy_s of the base body tilt angular velocity θbdot based on the acquired output of the tilt sensor 52.

  In the following description, when an observed value (measured value) of an actual value of a variable (state quantity) such as the measured value θb_xy_s is represented by a reference symbol, the subscript “_s” is added to the reference symbol of the variable. Is added.

  Next, after acquiring the output of the load sensor 54 in STEP 3, the control unit 50 executes the determination process in STEP 4. In this determination process, the control unit 50 determines whether or not an occupant is in the vehicle 1 depending on whether or not the load measurement value indicated by the acquired output of the load sensor 54 is greater than a predetermined value ( Whether or not an occupant is seated on the seat 3).

  If the determination result in STEP 4 is affirmative, the control unit 50 sets the target value θb_xy_obj of the base body tilt angle θb, and constant parameters for controlling the operation of the vehicle 1 (basic values of various gains, etc.) ) Is set in STEPs 5 and 6, respectively.

  In STEP 5, the control unit 50 sets a predetermined target value for the boarding mode as the target value θb_xy_obj of the base body tilt angle θb.

  Here, the “boarding mode” means an operation mode of the vehicle 1 when an occupant is on the vehicle 1. The target value θb_xy_obj for the boarding mode is such that the overall center of gravity of the vehicle 1 and the occupant seated on the seat 3 (hereinafter referred to as the vehicle / occupant overall center of gravity) is located almost directly above the ground contact surface of the wheel body 5. In the posture of the base body 9 in a state, it is set in advance so as to match or substantially match the measured value θb_xy_s of the base body tilt angle θb measured based on the output of the tilt sensor 52.

  In STEP 6, the control unit 50 sets a predetermined value for the boarding mode as a constant parameter value for controlling the operation of the vehicle 1. The constant parameters are hx, hy, Ki_a_x, Ki_b_x, Ki_a_y, Ki_b_y (i = 1, 2, 3), which will be described later.

  On the other hand, if the determination result in STEP 4 is negative, the control unit 50 performs processing for setting the target value θb_xy_obj of the base body tilt angle θb_xy, and processing for setting constant parameter values for operation control of the vehicle 1. Are executed in STEP7 and STEP8.

  In STEP 7, the control unit 50 sets a predetermined target value for the independent mode as the target value θb_xy_obj of the inclination angle θb.

  Here, the “self-supporting mode” means an operation mode of the vehicle 1 when no occupant is on the vehicle 1. The target value θb_xy_obj for the self-supporting mode is an inclination sensor in the posture of the base body 9 in which the center of gravity of the vehicle 1 (hereinafter referred to as the vehicle center of gravity) is positioned almost directly above the ground contact surface of the wheel body 5. It is set in advance so as to coincide with or substantially coincide with the measured value θb_xy_s of the base body tilt angle θb measured based on the output of 52. The target value θb_xy_obj for the self-supporting mode is generally different from the target value θb_xy_obj for the boarding mode.

  In STEP 8, the control unit 50 sets a predetermined value for the independent mode as a constant parameter value for controlling the operation of the vehicle 1. The value of the constant parameter for the independent mode is different from the value of the constant parameter for the boarding mode.

  The difference in the value of the constant parameter between the boarding mode and the independent mode is due to the difference in the height of the center of gravity, the overall mass, etc. in each mode, and the response of the operation of the vehicle 1 to the control input. This is because the characteristics are different from each other.

  Through the processing in STEPs 4 to 8 described above, the target value θb_xy_obj of the base body tilt angle θb_xy and the value of the constant parameter are set separately for each operation mode of the boarding mode and the self-supporting mode.

  Note that the processing in STEP 5 and 6 or the processing in STEP 7 and 8 is not essential to be executed every control processing cycle, and may be executed only when the determination result in STEP 4 changes.

  Supplementally, in both the boarding mode and the self-supporting mode, the target value of the component θbdot_x around the Y axis and the target value of the component θbdot_y around the X axis of the base body tilt angular velocity θbdot are both “0”. For this reason, the process which sets the target value of base | substrate inclination angular velocity (theta) bdot_xy is unnecessary.

  After executing the processing of STEPs 5 and 6 or the processing of STEPs 7 and 8 as described above, the control unit 50 next executes the vehicle control calculation processing in STEP 9 to thereby control the respective speed commands of the electric motors 31R and 31L. To decide. Details of this vehicle control calculation processing will be described later.

  Next, proceeding to STEP 10, the control unit 50 executes an operation control process for the electric motors 31R and 31L in accordance with the speed command determined in STEP 9. In this operation control process, the control unit 50 determines the deviation according to the deviation between the speed command of the electric motor 31R determined in STEP 9 and the measured value of the rotational speed of the electric motor 31R measured based on the output of the rotary encoder 56R. The target value (target torque) of the output torque of the electric motor 31R is determined so as to converge to “0”. Then, the control unit 50 controls the energization current of the electric motor 31R so that the output torque of the target torque is output to the electric motor 31R. The same applies to the operation control of the left electric motor 31L.

  The above is the overall control process executed by the control unit 50.

  Next, the details of the vehicle control calculation process in STEP 9 will be described.

  In the following description, the vehicle / occupant overall center-of-gravity point in the boarding mode and the vehicle single body center-of-gravity point in the autonomous mode are collectively referred to as a vehicle system center-of-gravity point. When the operation mode of the vehicle 1 is the boarding mode, the vehicle system center-of-gravity point means the vehicle / occupant overall center-of-gravity point, and when it is in the self-supporting mode, it means the vehicle single body center-of-gravity point.

  In the following description, regarding the value (value to be updated) determined by the control unit 50 in each control processing cycle, the value determined in the current (latest) control processing cycle is the current value, and the control processing immediately before that The value determined by the cycle may be referred to as the previous value. A value not particularly different from the current value and the previous value means the current value.

  Further, regarding the speed and acceleration in the X-axis direction, the forward direction is a positive direction, and regarding the speed and acceleration in the Y-axis direction, the left direction is a positive direction.

  In the present embodiment, the dynamic behavior of the center of gravity of the vehicle system (specifically, the behavior seen by projecting from the Y-axis direction onto a plane (XZ plane) orthogonal thereto, and orthogonal to the X-axis direction) The vehicle of STEP9 is assumed that the behavior (projected and projected on the plane (YZ plane)) is approximately expressed by the behavior of the inverted pendulum model (the dynamic behavior of the inverted pendulum) as shown in FIG. Control arithmetic processing is performed.

  In FIG. 8, reference numerals without parentheses are reference numerals corresponding to the inverted pendulum model viewed from the Y-axis direction, and reference numerals with parentheses refer to the inverted pendulum model viewed from the X-axis direction. Corresponding reference sign.

  In this case, the inverted pendulum model expressing the behavior seen from the Y-axis direction has a mass point 60_x located at the center of gravity of the vehicle system and a rotation axis 62a_x parallel to the Y-axis direction. Wheel 62_x (hereinafter referred to as virtual wheel 62_x). The mass point 60_x is supported by the rotation shaft 62a_x of the virtual wheel 62_x via the linear rod 64_x, and can swing around the rotation shaft 62a_x with the rotation shaft 62a_x as a fulcrum.

  In this inverted pendulum model, the motion of the mass point 60_x corresponds to the motion of the vehicle system center of gravity as viewed from the Y-axis direction. Further, the inclination angle θbe_x of the rod 64_x with respect to the vertical direction coincides with the deviation θbe_x_s (= θb_x_s−θb_x_obj) between the measured base body tilt angle value θb_x_s and the base body tilt angle target value θb_x_obj in the direction around the Y axis. Further, the changing speed (= dθbe_x / dt) of the inclination angle θbe_x of the rod 64_x is set to coincide with the measured body inclination angular velocity θbdot_x_s in the direction around the Y axis. Further, the movement speed Vw_x (translation movement speed in the X-axis direction) of the virtual wheel 62_x is the same as the movement speed in the X-axis direction of the wheel body 5 of the vehicle 1.

  Similarly, an inverted pendulum model (refer to the reference numerals in parentheses in FIG. 8) expressing the behavior viewed from the X-axis direction includes a mass point 60_y located at the vehicle system center of gravity and a rotation axis 62a_y parallel to the X-axis direction. And virtual wheels 62_y (hereinafter referred to as virtual wheels 62_y) that can rotate on the floor surface. The mass point 60_y is supported by the rotation shaft 62a_y of the virtual wheel 62_y via a linear rod 64_y, and can swing around the rotation shaft 62a_y with the rotation shaft 62a_y as a fulcrum.

  In this inverted pendulum model, the motion of the mass point 60_y corresponds to the motion of the vehicle system center-of-gravity point viewed from the X-axis direction. In addition, the inclination angle θbe_y of the rod 64_y with respect to the vertical direction coincides with the deviation θbe_y_s (= θb_y_s−θb_y_obj) between the measured base body tilt angle value θb_y_s and the base body tilt angle target value θb_y_obj in the direction around the X axis. In addition, the change speed (= dθbe_y / dt) of the inclination angle θbe_y of the rod 64_y coincides with the measured base body inclination angular velocity θbdot_y_s in the direction around the X axis. Further, the moving speed Vw_y (translational moving speed in the Y-axis direction) of the virtual wheel 62_y is set to coincide with the moving speed in the Y-axis direction of the wheel body 5 of the vehicle 1.

  The virtual wheels 62_x and 62_y are assumed to have predetermined radii of predetermined values Rw_x and Rw_y, respectively.

  Further, the rotational angular velocities ωw_x and ωw_y of the virtual wheels 62_x and 62_y and the rotational angular velocities ω_R and ω_L of the electric motors 31R and 31L (more precisely, the rotational angular velocities ω_R and ω_L of the rotating members 27R and 27L), respectively. The relationship of the following formulas 01a and 01b is established.

ωw_x = (ω_R + ω_L) / 2 Equation 01a
ωw_y = C · (ω_R−ω_L) / 2 …… Formula 01b

Note that “C” in the expression 01b is a coefficient of a predetermined value depending on the mechanical relationship between the free rollers 29R and 29L and the wheel body 5 and slippage. Further, the positive directions of ωw_x, ω_R, and ω_L are the rotation direction of the virtual wheel 62_x when the virtual wheel 62_x rotates forward, and the positive direction of ωw_y is the case when the virtual wheel 62_y rotates leftward. This is the rotation direction of the virtual wheel 62_y.

  Here, the dynamics of the inverted pendulum model shown in FIG. 8 is expressed by the following equations 03x and 03y. The expression 03x is an expression expressing the dynamics of the inverted pendulum model viewed from the Y-axis direction, and the expression 03y is an expression expressing the dynamics of the inverted pendulum model viewed from the X-axis direction.

d ² θbe_x / dt ² = α_x · θbe_x + β_x · ωwdot_x ...... Formula 03x
d ² θbe_y / dt ² = α_y · θbe_y + β_y · ωwdot_y ...... Formula 03y

In equation 03x, ωwdot_x is the rotational angular acceleration of the virtual wheel 62_x (first-order differential value of the rotational angular velocity ωw_x), α_x is a coefficient that depends on the mass and height h_x of the mass 60_x, and β_x is the inertia (moment of inertia of the virtual wheel 62_x ) And the radius Rw_x. The same applies to ωwdot_y, α_y, and β_y in Expression 03y.

  As can be seen from these equations 03x and 03y, the motions of the mass points 60_x and 60_y of the inverted pendulum (and hence the motion of the vehicle system center of gravity) are respectively the rotational angular acceleration ωwdot_x of the virtual wheel 62_x and the rotational angular acceleration ωwdot_y of the virtual wheel 62_y. It is defined depending on.

  Therefore, in the present embodiment, the rotational angular acceleration ωwdot_x of the virtual wheel 62_x is used as an operation amount (control input) for controlling the motion of the vehicle system center of gravity point viewed from the Y-axis direction, and viewed from the X-axis direction. The rotational angular acceleration ωwdot_y of the virtual wheel 62_y is used as an operation amount (control input) for controlling the motion of the vehicle system center of gravity.

  Then, the vehicle control arithmetic processing in STEP 9 will be schematically described. The control unit 50 determines that the motion of the mass point 60_x seen in the X-axis direction and the motion of the mass point 60_y seen in the Y-axis direction are Virtual wheel rotational angular acceleration commands ωwdot_x_cmd and ωwdot_y_cmd, which are command values (target values) of the rotational angular accelerations ωwdot_x and ωwdot_y as operation amounts, are determined so as to achieve a motion corresponding to a desired motion. Further, the control unit 50 integrates the virtual wheel rotation angular acceleration commands ωwdot_x_cmd and ωwdot_y_cmd, and the virtual wheel rotation that is the command values (target values) of the respective rotation angular velocities ωw_x and ωw_y of the virtual wheels 62_x and 62_y. The angular velocity commands are determined as ωw_x_cmd and ωw_y_cmd.

  Then, the control unit 50 moves the virtual wheel 62_x corresponding to the virtual wheel rotational angular velocity command ωw_x_cmd (= Rw_x · ωw_x_cmd) and the virtual wheel 62_y corresponding to the virtual wheel rotational angular velocity command ωw_y_cmd (= Rw_y · ωw_y_cmd). ) As the target movement speed in the X-axis direction and the target movement speed in the Y-axis direction of the wheel body 5 of the vehicle 1, and the respective speeds of the electric motors 31 </ b> R and 31 </ b> L so as to realize these target movement speeds. The commands ω_R_cmd and ωL_cmd are determined.

  In this embodiment, the virtual wheel rotation angular acceleration commands ωwdot_x_cmd and ωwdot_y_cmd as the operation amount (control input) are obtained by adding three operation amount components as shown in equations 07x and 07y described later, respectively. It is determined.

  Supplementally, among the virtual wheel rotation angular acceleration commands ωwdot_x_cmd and ωwdot_y_cmd as the operation amount (control input) in the present embodiment, ωwdot_x_cmd is the rotation angular velocity of the virtual wheel 62_x moving in the X-axis direction. This functions as an operation amount that defines the driving force to be applied to the wheel body 5 in order to move the wheel in the X-axis direction. Further, since ωwdot_y_cmd is the rotational angular velocity of the virtual wheel 62_y moving in the Y-axis direction, it functions as an operation amount that defines the driving force to be applied to the wheel body 5 in order to move the wheel body 5 in the Y-axis direction. To be.

  The control unit 50 has the function shown in the block diagram of FIG. 9 as a function for executing the vehicle control calculation process of STEP 9 as described above.

  That is, the control unit 50 calculates the base body tilt angle deviation measurement value θbe_xy_s, which is a deviation between the base body tilt angle measurement value θb_xy_s and the base body tilt angle target value θb_xy_obj, and the moving speed of the vehicle system center-of-gravity point. A target value of the center-of-gravity speed Vb_xy in consideration of a center-of-gravity speed calculation unit 72 that calculates an estimated center-of-gravity speed value Vb_xy_s as an observed value of a certain center-of-gravity speed Vb_xy As a control target center of gravity speed Vb_xy_mdfd, and a gain adjustment section 78 for determining a gain adjustment parameter Kr_xy for adjusting the values of gain coefficients of equations 07x and 07y described later.

  The control unit 50 further performs the virtual wheel rotation when an idle rotation occurs between the attitude control calculation unit 80 that calculates the basic value of the virtual wheel rotation angular velocity command ωw_xy_cmd and the wheel body 5 and the floor surface. An idling suppression unit 81 that determines a suppression coefficient λ that suppresses the angular velocity command ωw_xy_cmd, and a calculation unit 83 that calculates a value of the virtual wheel rotation angular velocity command ωw_xy_cmd modified by multiplying the virtual wheel rotation angular velocity command ωw_xy_cmd by the suppression coefficient λ. The virtual wheel rotational angular velocity command ωw_xy_cmd output from the calculation unit 83 is converted into a speed command ω_R_cmd (rotational angular velocity command value) for the right electric motor 31R and a speed command ω_L_cmd (rotational angular velocity command value) for the left electric motor 31L. And a motor command calculation unit 82 for conversion into a set of

  Note that the reference numeral 84 in FIG. 9 indicates a delay element for inputting the virtual wheel rotation angular velocity command ωw_xy_cmd calculated by the attitude control calculation unit 70 for each control processing cycle. The delay element 84 outputs the previous value ωw_xy_cmd_p of the virtual wheel rotation angular velocity command ωw_xy_cmd in each control processing cycle.

  In the vehicle control calculation process in STEP 9, the processes of the above-described respective processing units are executed as described below.

  That is, the control unit 50 first executes the process of the deviation calculation unit 70 and the process of the gravity center speed calculation unit 72.

  The deviation calculating unit 70 receives the measured base body tilt angle value θb_xy_s (θb_x_s and θb_y_s) calculated in STEP 2 and the target values θb_xy_obj (θb_x_obj and θb_y_obj) set in STEP 5 or STEP 7. Then, the deviation calculating unit 70 subtracts θb_x_obj from θb_x_s to calculate a measured body tilt angle deviation value θbe_x_s (= θb_x_s−θb_x_obj) around the Y axis, and subtracts θb_y_obj from θb_y_s to obtain X A base body tilt angle deviation measurement value θbe_y_s (= θb_y_s−θb_y_obj) in the direction around the axis is calculated.

  The process of the deviation calculating unit 70 may be performed before the vehicle control calculation process of STEP9. For example, the process of the deviation calculating unit 70 may be executed in the process of STEP 5 or 7.

  The center-of-gravity velocity calculation unit 72 receives the current value of the base body tilt angular velocity measurement value θbdot_xy_s (θbdot_x_s and θbdot_y_s) calculated in STEP 2 and the previous value ωw_xy_cmd_p (ωw_x_cmd_p and ωw_y_cmd_p) of the virtual wheel speed command ωw_xy_cmd. Input from the delay element 84. Then, the center-of-gravity speed calculation unit 72 calculates the center-of-gravity speed estimated values Vb_xy_s (Vb_x_s and Vb_y_s) from these input values using a predetermined arithmetic expression based on the inverted pendulum model.

  Specifically, the center-of-gravity velocity calculation unit 72 calculates Vb_x_s and Vb_y_s by the following equations 05x and 05y, respectively.

Vb_x_s = Rw_x · ωw_x_cmd_p + h_x · θbdot_x_s ...... 05x
Vb_y_s = Rw_y · ωw_y_cmd_p + h_y · θbdot_y_s …… 05y

In these expressions 05x and 05y, as described above, Rw_x and Rw_y are the radii of the virtual wheels 62_x and 62_y, and these values are predetermined values set in advance. H_x and h_y are the heights of the mass points 60_x and 60_y of the inverted pendulum model, respectively. In this case, in the present embodiment, the height of the vehicle system center-of-gravity point is maintained substantially constant. Therefore, predetermined values set in advance are used as the values of h_x and h_y, respectively. Supplementally, the heights h_x and h_y are included in the constant parameters whose values are set in STEP 6 or 8.

  The first term on the right side of the formula 05x is the moving speed in the X-axis direction of the virtual wheel 62_x corresponding to the previous value ωw_x_cmd_p of the speed command of the virtual wheel 62_x, and this moving speed is the X-axis direction of the wheel body 5 This corresponds to the current value of the actual movement speed. Further, the second term on the right side of the expression 05x is the movement speed in the X-axis direction of the vehicle system center-of-gravity point caused by the base body 9 tilting at the inclination angular velocity of θbdot_x_s around the Y axis (relative to the wheel body 5). This is equivalent to the current value of the movement speed. The same applies to Formula 05y.

  Note that a set of measured values (current values) of the respective rotational angular velocities of the electric motors 31R and 31L measured based on the outputs of the rotary encoders 56R and 56L is converted into a set of rotational angular velocities of the virtual wheels 62_x and 62_y. The rotational angular velocities may be converted and used in place of ωw_x_cmd_p and ωw_y_cmd_p in equations 05x and 05y. However, it is advantageous to use the target values ωw_x_cmd_p and ωw_y_cmd_p in order to eliminate the influence of noise included in the measured value of the rotational angular velocity.

  Next, the control unit 50 executes the process of the gravity center speed limiting unit 76 and the process of the gain adjusting unit 78. In this case, the center-of-gravity speed limiter 76 and the gain adjustment unit 78 are input with the center-of-gravity speed estimated values Vb_xy_s (Vb_x_s and Vb_y_s) calculated by the center-of-gravity speed calculator 72 as described above.

  Then, the gain adjustment unit 78 determines the gain adjustment parameter Kr_xy (Kr_x and Kr_y) based on the input center-of-gravity velocity estimated value Vb_xy_s (Vb_x_s and Vb_y_s).

  The processing of the gain adjusting unit 78 will be described below with reference to FIGS.

  As shown in FIG. 10, the gain adjustment unit 78 inputs the input center-of-gravity velocity estimated values Vb_x_s and Vb_y_s to the limit processing unit 86. In the limit processing unit 86, output values Vw_x_lim1 and Vw_y_lim1 are generated by appropriately adding limits corresponding to the allowable ranges of the rotational angular velocities of the electric motors 31R and 31L to the gravity center speed estimated values Vb_x_s and Vb_y_s. The output value Vw_x_lim1 has a meaning after limiting the moving speed Vw_x in the X-axis direction of the virtual wheel 62_x, and the output value Vw_y_lim1 has a meaning as a value after limiting the moving speed Vw_y in the Y-axis direction of the virtual wheel 62_y. .

  The processing of the limit processing unit 86 will be described in more detail with reference to FIG. Note that the reference numerals in parentheses in FIG. 11 indicate processing of the limit processing unit 104 of the gravity center speed limiting unit 76 described later, and may be ignored in the description of the processing of the limit processing unit 86.

  First, the limit processing unit 86 inputs the center-of-gravity velocity estimated values Vb_x_s and Vb_y_s to the processing units 86a_x and 86a_y, respectively. The processing unit 86a_x divides Vb_x_s by the radius Rw_x of the virtual wheel 62_x to calculate the rotational angular velocity ωw_x_s of the virtual wheel 62_x when it is assumed that the moving speed in the X-axis direction of the virtual wheel 62_x matches Vb_x_s. . Similarly, the processing unit 86a_y calculates the rotational angular velocity ωw_y_s (= Vb_y_s / Rw_y) of the virtual wheel 62_y when it is assumed that the moving speed of the virtual wheel 62_y in the Y-axis direction matches Vb_y_s.

  Next, the limit processing unit 86 converts the set of ωw_x_s and ωw_y_s into a set of the rotation angular velocity ω_R_s of the electric motor 31R and the rotation angular velocity ω_L_s of the electric motor 31L by the XY-RL conversion unit 86b.

  In this embodiment, this conversion is performed by solving simultaneous equations obtained by replacing ωw_x, ωw_y, ω_R, and ω_L in the equations 01a and 01b with ωw_x_s, ωw_y_s, ω_R_s, and ω_L_s, with ω_R_s and ω_L_s as unknowns. Done.

  Next, the limit processing unit 86 inputs the output values ω_R_s and ω_L_s of the XY-RL conversion unit 86b to the limiters 86c_R and 86c_L, respectively. At this time, if the limiter 86c_R is within the allowable range for the right motor having a predetermined upper limit value (> 0) and lower limit value (<0), the limiter 86c_R keeps ω_R_s as it is. Output as output value ω_R_lim1. Further, when ω_R_s deviates from the right motor allowable range, the limiter 86c_R outputs the boundary value closer to ω_R_s between the upper limit value and the lower limit value of the right motor allowable range as the output value ω_R_lim1. Output as. As a result, the output value ω_R_lim1 of the limiter 86c_R is limited to a value within the allowable range for the right motor.

  Similarly, when the limiter 86c_L is within the allowable range for the left motor having a predetermined upper limit value (> 0) and lower limit value (<0), the limiter 86c_L keeps ω_L_s as it is. Output as output value ω_L_lim1. Further, when ω_L_s deviates from the left motor allowable range, the limiter 86c_L outputs the boundary value closer to ω_L_s between the upper limit value and the lower limit value of the left motor allowable range as the output value ω_L_lim1. Output as. As a result, the output value ω_L_lim1 of the limiter 86c_L is limited to a value within the left motor allowable range.

  The allowable range for the right motor is set so that the rotational angular velocity (absolute value) of the right electric motor 31R does not become too high, and in turn prevents the maximum value of torque that can be output by the electric motor 31R from decreasing. Tolerance. The same applies to the allowable range for the left motor.

  Next, the limit processing unit 86 converts the set of output values ω_R_lim1 and ω_L_lim1 of the limiters 86c_R and 86c_L into sets of rotational angular velocities ωw_x_lim1 and ωw_y_lim1 of the virtual wheels 62_x and 62_y by the RL-XY conversion unit 86d. .

  This conversion is a reverse conversion process of the conversion process of the XY-RL conversion unit 86b. This processing is performed by solving simultaneous equations obtained by replacing ωw_x, ωw_y, ω_R, and ω_L in the equations 01a and 01b with ωw_x_lim1, ωw_y_lim1, ω_R_lim1, and ω_L_lim1 as ωw_x_lim1 and ωw_y_lim1.

  Next, the limit processing unit 86 inputs the output values ωw_x_lim1 and ωw_y_lim1 of the RL-XY conversion unit 86d to the processing units 86e_x and 86e_y, respectively. The processing unit 86e_x converts ωw_x_lim1 into the moving speed Vw_x_lim1 of the virtual wheel 62_x by multiplying ωw_x_lim1 by the radius Rw_x of the virtual wheel 62_x. Similarly, the processor 86e_y converts ωw_y_lim1 into the moving speed Vw_y_lim1 (= ωw_y_lim1 · Rw_y) of the virtual wheel 62_y.

  It is assumed that the movement speed Vw_x of the virtual wheel 62_x in the X-axis direction and the movement speed Vw_y of the virtual wheel 62_y in the Y-axis direction are made to coincide with the center-of-gravity speed estimated values Vb_x_s and Vb_y_s, respectively, by the above processing of the limit processing unit 86. In other words (in other words, assuming that the moving speed in the X-axis direction and the moving speed in the Y-axis direction of the wheel body 5 are respectively matched with Vb_x_s and Vb_y_s), it is necessary to realize those moving speeds. When the rotational angular velocities ω_R_s and ω_L_s of the electric motors 31R and 31L are both within the allowable range, a set of output values Vw_x_lim1 and Vw_y_lim1 that respectively match Vb_x_s and Vb_y_s is obtained from the limit processing unit 86. Is output.

  On the other hand, when both or one of the rotational angular velocities ω_R_s and ω_L_s of the electric motors 31R and 31L deviate from the allowable range, both or one of the rotational angular velocities is forcibly limited within the allowable range. Thus, the limit processing unit 86 outputs a set of movement speeds Vw_x_lim1 and Vw_y_lim1 in the X-axis direction and the Y-axis direction corresponding to the set of rotational angular velocities ω_R_lim1 and ω_L_lim1 of the electric motors 31R and 31L after the limitation.

  Therefore, the limit processing unit 86 can make the rotation angular velocities of the electric motors 31R and 31L corresponding to the set of the output values Vw_x_lim1 and Vw_y_lim1 not to deviate from the permissible range under the necessary conditions. As long as the output values Vw_x_lim1 and Vw_y_lim1 coincide with Vb_x_s and Vb_y_s, a set of output values Vw_x_lim1 and Vw_y_lim1 is generated.

  Returning to the description of FIG. 10, the gain adjustment unit 78 next executes the processing of the calculation units 88_x and 88_y. The calculation unit 88_x receives the estimated center-of-gravity velocity value Vb_x_s in the X-axis direction and the output value Vw_x_lim1 of the limit processing unit 86. Then, the calculation unit 88_x calculates and outputs a value Vover_x obtained by subtracting Vb_x_s from Vw_x_lim1. Further, the Y-axis direction center of gravity velocity estimated value Vb_y_s and the output value Vw_y_lim1 of the limit processing unit 86 are input to the arithmetic unit 88_y. The computing unit 88_y calculates and outputs a value Vover_y obtained by subtracting Vb_y_s from Vw_y_lim1.

  In this case, if the output values Vw_x_lim1 and Vw_y_lim1 are not forcibly limited by the limit processing unit 86, Vw_x_lim1 = Vb_x_s and Vw_y_lim1 = Vb_y_s, and thus the output values Vover_x of the arithmetic units 88_x and 88_y, respectively. , Vover_y is “0”.

  On the other hand, when the output values Vw_x_lim1 and Vw_y_lim1 of the limit processing unit 86 are generated by forcibly limiting the input values Vb_x_s and Vb_y_s, the correction amount (= Vw_x_lim1−Vb_x_s) of Vw_x_lim1 from Vb_x_s , And Vw_y_lim1 are corrected from Vb_y_s (= Vw_y_lim1-Vb_y_s) from the arithmetic units 88_x and 88_y, respectively.

  Next, the gain adjustment unit 78 determines the gain adjustment parameter Kr_x by sequentially passing the output value Vover_x of the calculation unit 88_x through the processing units 90_x and 92_x. Further, the gain adjustment unit 78 determines the gain adjustment parameter Kr_y by sequentially passing the output value Vover_y of the calculation unit 88_y through the processing units 90_y and 92_y. The gain adjustment parameters Kr_x and Kr_y are both values in the range from “0” to “1”.

  The processing unit 90_x calculates and outputs the absolute value of the input Vover_x. Further, the processing unit 92_x generates Kr_x so that the output value Kr_x monotonously increases with respect to the input value | Vover_x | and has a saturation characteristic. The saturation characteristic is a characteristic in which the change amount of the output value with respect to the increase of the input value becomes “0” or approaches “0” when the input value increases to some extent.

  In this case, in this embodiment, when the input value | Vover_x | is equal to or less than a predetermined value, the processing unit 92_x sets a value obtained by multiplying the input value | Vover_x | by a proportional coefficient of the predetermined value. Output as Kr_x. In addition, when the input value | Vover_x | is larger than a predetermined value, the processing unit 92_x outputs “1” as Kr_x. The proportional coefficient is set so that the product of | Vover_x | and the proportional coefficient is “1” when | Vover_x | matches a predetermined value.

  The processing of the processing units 90_y and 92_y is the same as the processing of the above-described processing units 90_x and 92_x, respectively.

  When the output values Vw_x_lim1 and Vw_y_lim1 are not forcibly limited by the limit processing unit 86 by the processing of the gain adjusting unit 78 described above, that is, in the X axis direction and the Y axis direction of the wheel body 5 respectively. Even if the electric motors 31R and 31L are operated so that the movement speeds Vw_x and Vw_y coincide with the center-of-gravity speed estimated values Vb_x_s and Vb_y_s, the respective rotational angular velocities of the electric motors 31R and 31L are within the allowable range. In this case, the gain adjustment parameters Kr_x and Kr_y are both determined to be “0”. Therefore, normally, Kr_x = Kr_y = 0.

  On the other hand, when the output values Vw_x_lim1 and Vw_y_lim1 of the limit processing unit 86 are generated by forcibly limiting the input values Vb_x_s and Vb_y_s, that is, in the X axis direction and the Y axis direction of the wheel body 5 respectively. If the electric motors 31R and 31L are operated so that the moving speeds Vw_x and Vw_y coincide with the center-of-gravity speed estimated values Vb_x_s and Vb_y_s, respectively, the rotational angular speed of either of the electric motors 31R and 31L deviates from the allowable range. In the case (when the absolute value of one of the rotational angular velocities becomes too high), the gain adjustment parameters Kr_x and Kr_y are determined according to the absolute values of the correction amounts Vover_x and Vover_y, respectively. In this case, Kr_x is determined to have a larger value as the absolute value of the correction amount Vx_over increases with “1” as the upper limit. The same applies to Kr_y.

  Further, the center-of-gravity speed limiter 76 uses the input estimated center-of-gravity speed value Vb_xy_s (Vb_x_s and Vb_y_s) to execute the processing shown in the block diagram of FIG. 12, thereby controlling the target gravity center speed Vb_xy_mdfd (Vb_x_mdfd). And Vb_y_mdfd).

  Specifically, the center-of-gravity speed limiting unit 76 first executes the processes of the steady deviation calculating units 94_x and 94_y.

  In this case, the steady-state deviation calculating unit 94_x receives the estimated center-of-gravity velocity value Vb_x_s in the X-axis direction and the previous value Vb_x_mdfd_p of the control target center-of-gravity velocity Vb_x_mdfd in the X-axis direction via the delay element 96_x. . The steady deviation calculating unit 94_x first inputs the input Vb_x_s to the proportional / differential compensation element (PD compensation element) 94a_x. The proportional / differential compensation element 94_x is a compensation element whose transfer function is represented by 1 + Kd · S, and is obtained by multiplying the input Vb_x_s and its differential value (time change rate) by a predetermined coefficient Kd. Add the value and output the result of the addition.

  Next, the steady deviation calculating unit 94_x calculates a value obtained by subtracting the input Vb_x_mdfd_p from the output value of the proportional / differential compensation element 94_x by the calculating unit 94b_x, and then outputs the output value of the calculating unit 94b_x to the phase compensation It inputs into the low-pass filter 94c_x which has a function. The low-pass filter 94c_x is a filter whose transfer function is represented by (1 + T2 · S) / (1 + T1 · S). The steady deviation calculating unit 94_x outputs the output value Vb_x_prd of the low-pass filter 94c_x.

  In addition, the steady-state deviation calculating unit 94_y receives the Y-axis centroid speed estimated value Vb_y_s and the previous value Vb_y_mdfd_p of the Y-axis control target centroid speed Vb_y_mdfd via the delay element 96_y.

  Then, similarly to the above-described steady deviation calculation unit 94_x, the steady deviation calculation unit 94_y sequentially executes the processing of the proportional / differential compensation element 94a_y, the calculation unit 94b_y, and the low-pass filter 94c_y, and outputs the output value Vb_y_prd of the low-pass filter 94c_y. To do.

  Here, the output value Vb_x_prd of the steady deviation calculating unit 94_x is based on the current motion state of the vehicle system center of gravity as viewed from the Y-axis direction (in other words, the motion state of the mass point 60_x of the inverted pendulum model as viewed from the Y-axis direction). It has a meaning as a steady deviation with respect to the control target center-of-gravity speed Vb_x_mdfd of the estimated predicted center-of-gravity speed estimated value in the X-axis direction. Similarly, the steady deviation calculating unit 94_y output value Vb_y_prd is estimated from the current motion state of the vehicle system center of gravity as viewed from the X-axis direction (in other words, the motion state of the mass point 60_y of the inverted pendulum model as viewed from the X-axis direction). The convergence predicted value of the estimated center-of-gravity speed value in the future Y-axis direction has a meaning as a steady deviation with respect to the control target center-of-gravity speed Vb_y_mdfd. Hereinafter, the respective output values Vb_x_prd and Vb_y_prd of the steady deviation calculation units 94_x and 94_y are referred to as center-of-gravity velocity steady deviation prediction values.

  The center-of-gravity speed limiter 76 executes the processes of the steady-state deviation calculators 94_x and 94_y as described above, and then inputs the center-of-gravity speed steady-state deviation predicted values Vb_x_prd and Vb_y_prd to the limit processor 100. The processing of the limit processing unit 100 is the same as the processing of the limit processing unit 86 of the gain adjustment unit 78 described above. In this case, only the input value and the output value of each processing unit of the limit processing unit 100 are different from the limit processing unit 86, as indicated by reference numerals in parentheses in FIG.

  Specifically, in the limit processing unit 100, it is assumed that the moving speeds Vw_x and Vw_y of the virtual wheels 62_x and 62_y coincide with Vb_x_prd and Vb_y_prd, respectively, and the rotational angular velocities ωw_x_t, ωw_y_t is calculated by the processing units 86a_x and 86a_y, respectively. Then, a set of the rotational angular velocities ωw_x_t and ωw_y_t is converted into a set of rotational angular velocities ω_R_t and ω_L_t of the electric motors 31R and 31L by the XY-RL converter 86b.

  Further, these rotational angular velocities ω_R_t and ω_L_t are limited by the limiters 86c_R and 86c_L to values within the allowable range for the right motor and values within the allowable range for the left motor, respectively. Then, the values ω_R_lim2 and ω_L_lim2 after the restriction process are converted into the rotational angular velocities ωw_x_lim2 and ωw_y_lim2 of the virtual wheels 62_x and 62_y by the RL-XY conversion unit 86d.

  Next, the moving speeds Vw_x_lim2 and Vw_y_lim2 of the virtual wheels 62_x and 62_y corresponding to the rotational angular velocities ωw_x_lim2 and ωw_y_lim2 are calculated by the processing units 86e_x and 86e_y, respectively, and the moving speeds Vw_x_lim2 and Vw_y_lim2 are output from the limit processing unit 100. The

  By the above processing of the limit processing unit 100, the limit processing unit 100, like the limit processing unit 86, has the rotational angular velocities of the electric motors 31R and 31L corresponding to the set of output values Vw_x_lim2 and Vw_y_lim2 deviate from the allowable range. It is an essential requirement that the output values Vw_x_lim2 and Vw_y_lim2 are generated so that the output values Vw_x_lim2 and Vw_y_lim2 coincide with Vb_x_t and Vb_y_t, respectively, as much as possible under the necessary conditions.

  Note that the permissible ranges for the right motor and the left motor in the limit processing unit 100 need not be the same as the permissible ranges in the limit processing unit 86, and may be set to different permissible ranges.

  Returning to the description of FIG. 12, the center-of-gravity speed limiting unit 76 next calculates the control target center-of-gravity speeds Vb_x_mdfd and Vb_y_mdfd by executing the processing of the calculation units 102_x and 102_y, respectively. In this case, the calculation unit 102_x calculates a value obtained by subtracting the X-axis direction center-of-gravity velocity steady deviation predicted value Vb_x_prd from the output value Vw_x_lim2 of the limit processing unit 100 as the control target center-of-gravity velocity Vb_x_mdfd. Similarly, the calculation unit 102_y calculates a value obtained by subtracting the Y-axis direction center-of-gravity velocity steady-state deviation predicted value Vb_y_prd from the output value Vw_y_lim2 of the limit processing unit 100 as the Y-axis direction control center-of-gravity velocity Vb_y_mdfd.

  The control target center-of-gravity velocities Vb_x_mdfd and Vb_y_mdfd determined as described above are obtained when the output values V_x_lim2 and V_y_lim2 in the limit processing unit 100 are not forcibly limited, that is, in the X-axis direction of the wheel body 5. Even if the electric motors 31R and 31L are operated so that the respective movement speeds in the Y-axis direction coincide with the center-of-gravity speed steady-state deviation predicted values Vb_x_prd and Vb_y_prd, the rotational angular speeds of the electric motors 31R and 31L are allowed. When it falls within the range, the control target center-of-gravity speeds Vb_x_mdfd and Vb_y_mdfd are both determined to be “0”. Therefore, normally, Vb_x_mdfd = Vb_y_mdfd = 0.

  On the other hand, when the output values Vw_x_lim2 and Vw_y_lim2 of the limit processing unit 100 are generated by forcibly limiting the input values Vb_x_t and Vb_y_t, that is, the X axis direction and the Y axis direction of the wheel body 5 respectively. When the electric motors 31R and 31L are operated so that the moving speeds coincide with the center-of-gravity speed steady deviation predicted values Vb_x_prd and Vb_y_prd, respectively, the rotational angular speed of either of the electric motors 31R and 31L deviates from the allowable range. (When the absolute value of one of the rotational angular velocities is too high), the correction amount (= Vw_x_lim2-Vb_x_prd) from the input value Vb_x_prd of the output value Vw_x_lim2 of the limit processing unit 100 is X axis in the X axis direction. This is determined as the target control center of gravity velocity Vb_x_mdfd.

  For the Y-axis direction, a correction amount (= Vw_y_lim2-Vb_y_prd) from the input value Vb_y_prd of the output value Vw_y_lim2 of the limit processing unit 100 is determined as the control target center-of-gravity velocity Vb_y_mdfd in the Y-axis direction.

  In this case, for example, regarding the speed in the X-axis direction, the control target center-of-gravity speed Vb_x_mdfd is a speed opposite to the X-axis direction center-of-gravity speed steady deviation predicted value Vb_x_prd output by the steady deviation calculating unit 94_x. The same applies to the speed in the Y-axis direction.

  The above is the process of the gravity center speed limiting unit 76.

  Returning to the description of FIG. 9, the control unit 50 executes the processes of the gravity center speed limiter 76, the gain adjuster 78, and the deviation calculator 70 as described above, and then executes the process of the attitude control calculator. To do.

  The processing of the attitude control calculation unit 80 will be described below with reference to FIG. In FIG. 13, reference numerals without parentheses are reference numerals related to processing for determining the virtual wheel rotation angular velocity command ωw_x_cmd that is a target value of the rotation angular velocity of the virtual wheel 62_x rotating in the X-axis direction. The reference numerals in parentheses are reference numerals related to the process of determining the virtual wheel rotation angular velocity command ωw_y_cmd that is the target value of the rotation angular velocity of the virtual wheel 62_y rotating in the Y-axis direction.

  The posture control calculation unit 80 includes a base body tilt angle deviation measurement value θbe_xy_s calculated by the deviation calculation unit 70, a base body tilt angular velocity measurement value θbdot_xy_s calculated in STEP2, and a center of gravity speed calculated by the center of gravity speed calculation unit 72. The estimated value Vb_xy_s, the control target center-of-gravity speed Vb_xy_mdfd calculated by the center-of-gravity speed limiting unit 76, and the gain adjustment parameter Kr_xy calculated by the gain adjustment unit 78 are input.

  The attitude control calculation unit 80 first calculates a virtual wheel rotation angular acceleration command ωdotw_xy_cmd by using the following expressions 07x and 07y using these input values.

ωwdot_x_cmd = K1_x ・ θbe_x_s + K2_x ・ θbdot_x_s
+ K3_x · (Vb_x_s−Vb_x_mdfd) ...... Formula 07x
ωwdot_y_cmd = K1_y ・ θbe_y_s + K2_y ・ θbdot_y_s
+ K3_y · (Vb_y_s−Vb_y_mdfd) …… Formula 07y

Therefore, in the present embodiment, as an operation amount (control input) for controlling the motion of the mass point 60_x of the inverted pendulum model viewed from the Y-axis direction (and hence the motion of the vehicle system center-of-gravity point viewed from the Y-axis direction). Virtual wheel rotation angular acceleration command ωdotw_x_cmd and operation amount (control input) for controlling the motion of the mass point 60_y of the inverted pendulum model viewed from the X-axis direction (and hence the motion of the center of gravity of the vehicle system viewed from the X-axis direction) The virtual wheel rotation angular acceleration command ωdotw_y_cmd is determined by adding three manipulated variable components (three terms on the right side of equations 07x and 07y).

  In these equations 07x and 07y, the gain coefficients K1_x and K1_y are feedback gains related to the inclination angle of the base 9 (or the sheet 3), and the gain coefficients K2_x and K2_y are the inclination angular velocities (time of the inclination angle) of the base 9 (or the sheet 3). The feedback gain and gain coefficients K3_x and K3_y related to the dynamic change rate have a meaning as a feedback gain related to the moving speed of the vehicle system center-of-gravity point (a predetermined representative point of the vehicle 1).

  In this case, the gain coefficients K1_x, K2_x, K3_x related to each manipulated variable component in the expression 07x are variably set according to the gain adjustment parameter Kr_x, and the gain coefficients K1_y, K2_y, K3_y related to each manipulated variable component in the expression 07y. Is variably set according to the gain adjustment parameter Kr_y. Hereinafter, the gain coefficients K1_x, K2_x, and K3_x in Expression 07x may be referred to as a first gain coefficient K1_x, a second gain coefficient K2_x, and a third gain coefficient K3_x, respectively. The same applies to the gain coefficients K1_y, K2_y, and K3_y in Expression 07y.

  The i-th gain coefficient Ki_x (i = 1, 2, 3) in Expression 07x and the i-th gain coefficient Ki_y (i = 1, 2, 3) in Expression 07y are as follows. It is determined according to the gain adjustment parameters Kr_x and Kr_y by the equations 09x and 09y.

Ki_x = (1−Kr_x) · Ki_a_x + Kr_x · Ki_b_x ...... Expression 09x
Ki_y = (1−Kr_y) · Ki_a_y + Kr_y · Ki_b_y ...... Equation 09y
(I = 1, 2, 3)

Here, Ki_a_x and Ki_b_x in Expression 09x are preliminarily set as the gain coefficient value on the minimum side (side closer to “0”) and the gain coefficient value on the maximum side (side away from “0”) of the i-th gain coefficient Ki_x, respectively. It is a set constant value. The same applies to Ki_a_y and Ki_b_y in Expression 09y.

  Accordingly, each i-th gain coefficient Ki_x (i = 1, 2, 3) used in the calculation of Expression 07x is determined as a weighted average value of the corresponding constant values Ki_a_x and Ki_b_x. In this case, the weights applied to Ki_a_x and Ki_b_x are changed according to the gain adjustment parameter Kr_x. Therefore, when Kr_x = 0, Ki_x = Ki_a_x, and when Kr_x = 1, Ki_x = Ki_b_x. As Kr_x approaches “1” from “0”, the i-th gain coefficient Ki_x approaches Ki_b_x from Ki_a_x.

  Similarly, each i-th gain coefficient Ki_y (i = 1, 2, 3) used in the calculation of Expression 07y is determined as a weighted average value of the corresponding constant values Ki_a_y and Ki_b_y. In this case, the weights applied to Ki_a_y and Ki_b_y are changed according to the gain adjustment parameter Kr_y. Therefore, as in the case of Ki_x, as the value of Kr_y changes between “0” and “1”, the value of the i-th gain coefficient Ki_y changes between Ki_a_y and Ki_b_y.

  As described above, Kr_x and Kr_y are normally “0” (specifically, when the output values Vw_x_lim1 and Vw_y_lim1 in the limit processing unit 86 of the gain adjusting unit 78 are not forcibly limited). is there. Accordingly, the i-th gain coefficients Ki_x and Ki_y (i = 1, 2, 3) are usually Ki_x = Ki_a_x and Ki_y = Ki_a_y, respectively.

  Supplementally, the constant values Ki_a_x, Ki_b_x and Ki_a_y, Ki_b_y (i = 1, 2, 3) are included in the constant parameters whose values are set in STEP 6 or 8.

  In the present embodiment, in the situation where Kr_x = 0 and Kr_y = 0, the ratio of the third gain coefficient K3_x related to the expression 07x to the first gain coefficient K1_x relative to the absolute value of the third gain coefficient K3_x and the third gain coefficient K3_y related to the expression 07y The ratio of the absolute value to the first gain coefficient K1_y differs between the boarding mode and the independent mode, which will be described later.

  The attitude control calculation unit 80 calculates the expression 07x using the first to third gain coefficients K1_x, K2_x, and K3_x determined as described above, so that the virtual wheel related to the virtual wheel 62_x that rotates in the X-axis direction. Rotational angular acceleration command ωwdot_x_cmd is calculated.

  In more detail, with reference to FIG. 13, the posture control calculation unit 80 sets the manipulated variable component u1_x obtained by multiplying the base body tilt angle deviation measured value θbe_x_s by the first gain coefficient K1_x and the base body tilt angular velocity measured value θbdot_x_s. The operation amount component u2_x obtained by multiplying the two gain coefficients K2_x is calculated by the processing units 80a and 80b, respectively. Further, the attitude control calculation unit 80 calculates a deviation (= Vb_x_s−Vb_x_mdfd) between the estimated center-of-gravity velocity value Vb_x_s and the target gravity center velocity for control Vb_x_mdfd (= Vb_x_s−Vb_x_mdfd), and multiplies this deviation by the third gain coefficient K3_x. The operation amount u3_x is calculated by the processing unit 80c. Then, the posture control calculation unit 80 calculates the virtual wheel rotation angular acceleration command ωwdot_x_cmd by adding these manipulated variable components u1_x, u2_x, u3_x in the calculation unit 80e.

  Similarly, the posture control calculation unit 80 calculates the expression 07y using the first to third gain coefficients K1_y, K2_y, and K3_y determined as described above, so that the virtual wheel 62_y that rotates in the Y-axis direction is obtained. The related virtual wheel rotation angular acceleration command ωwdot_y_cmd is calculated.

  In this case, the posture control calculation unit 80 multiplies the operation amount component u1_y obtained by multiplying the base body tilt angle deviation measurement value θbe_y_s by the first gain coefficient K1_y and the base body tilt angular velocity measurement value θbdot_y_s by the second gain coefficient K2_y. The operation amount component u2_y is calculated by the processing units 80a and 80b, respectively. Further, the attitude control calculation unit 80 calculates a deviation (= Vb_y_s−Vb_y_mdfd) between the center-of-gravity velocity estimated value Vb_y_s and the control target center-of-gravity velocity Vb_y_mdfd by the calculation unit 80d, and multiplies this deviation by the third gain coefficient K3_y. The operation amount u3_y is calculated by the processing unit 80c. Then, the attitude control calculation unit 80 calculates the virtual wheel rotation angular acceleration command ωwdot_x_cmd by adding these manipulated variable components u1_y, u2_y, u3_y in the calculation unit 80e.

  Here, the first term (= the first manipulated variable component u1_x) and the second term (= the second manipulated variable component u2_x) on the right side of the expression 07x are the body tilt angle deviation measured values θbe_x_s in the direction around the X axis, It has a meaning as a feedback manipulated variable component for converging to “0” (converging the base body tilt angle measurement value θb_x_s to the target value θb_x_obj) by the PD law (proportional / differential law) as a feedback control law.

  In addition, the third term (= third manipulated variable component u3_x) on the right side of Expression 07x converges to “0” by the proportional law as the feedback control law for the deviation between the center of gravity speed estimated value Vb_x_s and the control target center of gravity speed Vb_x_mdfd. It has a meaning as a feedback manipulated variable component for causing Vb_x_s to converge to Vb_x_mdfd.

  The same applies to the first to third terms (first to third manipulated variable components u1_y, u2_y, u3_y) on the right side of Expression 07y.

  Normally, as described above (more specifically, when the output values V_x_lim2 and V_y_lim2 are not forcibly limited by the limit processing unit 100 of the centroid speed limiting unit 76), the control target centroid speed Vb_x_mdfd , Vb_y_mdfd is “0”. In the normal case where Vb_x_mdfd = Vb_y_mdfd = 0, the third manipulated variable components u3_x and u3_y match the values obtained by multiplying the center-of-gravity velocity estimated values Vb_x_s and Vb_y_s by the third gain coefficients K3_x and K3_y, respectively.

  The attitude control calculation unit 80 calculates the virtual wheel rotation angular acceleration commands ωwdot_x_cmd and ωwdot_y_cmd as described above, and then integrates the ωwdot_x_cmd and ωwdot_y_cmd by the integrator 80f, thereby obtaining the virtual wheel rotation angular velocity command. Determine ωw_x_cmd and ωw_y_cmd.

  Supplementally, the third term on the right side of Expression 07x is hypothesized by an expression that is separated into an operation amount component (= K3_x · Vb_x_s) according to Vb_x_s and an operation amount component (= −K3_x · Vb_x_mdfd) according to Vb_x_mdfd. The wheel rotation angular acceleration command ωdotw_x_cmd may be calculated. Similarly, the third term on the right side of Expression 07y is divided into an operation amount component (= K3_y · Vb_y_s) according to Vb_y_s and an operation amount component (= −K3_y · Vb_y_mdfd) according to Vb_y_mdfd, The wheel rotation angular acceleration command ωdotw_y_cmd may be calculated.

  In the present embodiment, the rotational angular velocity commands ωw_x_cmd and ωw_y_cmd of the virtual wheels 62_x and 62_y are used as the operation amount (control input) for controlling the behavior of the vehicle system center of gravity. However, for example, the virtual wheels 62_x 62_y or a translational force obtained by dividing the driving torque by the radii Rw_x and Rw_y of the virtual wheels 62_x and 62_y (that is, the frictional force between the virtual wheels 62_x and 62_y and the floor surface). You may make it use as.

  The above is the details of the processing of the attitude control calculation unit 80.

  Next, details of the processing of the idling suppression unit 81 will be described with reference to FIGS.

  In this embodiment, the idling suppression unit 81 detects the occurrence of idling of the wheel body 5 and suppresses the moving operation of the wheel body 5 according to the inclination angle of the base body 9 (and the seat 3) when idling occurs. Therefore, the suppression coefficient λ is determined.

  First, the idling suppression unit 81 executes the process of STEP 21. In this process, the idling suppression unit 81 calculates the floor reaction force F_xy acting on the vehicle 1 from the observed amount relating to the tilt posture of the base body 9 and the state quantity relating to the moving motion of the wheel body 5, and the calculated floor reaction force F_xy. The predicted torque value T_xy_exp required to be applied to the virtual wheels 62_x and 62_y in order to generate

  In the following description, when a predicted value (predicted value) of a variable (state quantity) such as the predicted value T_xy_exp is expressed by a reference symbol, a subscript “_exp” is added to the reference symbol of the variable.

  In STEP 21, specifically, the idling suppression unit 81 first calculates the center-of-gravity speed estimated by the equations 05 x and 05 y and input from the center-of-gravity speed calculation unit 72 using an inclination model related to the overall center of gravity of the vehicle 1. The value (= −Vbdot_xy_s) obtained by differentiating the value Vb_xy_s is divided by the gravitational acceleration constant g multiplied by the base body tilt angle measurement value θb_xy_s (= g · θb_xy_s), and the total weight M of the vehicle body 1 is divided by the divided value. The floor reaction force F_xy (= (− Vbdot_xy_s + g · θb_xy_s) · M) is obtained by using the multiplied value to balance the floor reaction force F_xy of the virtual wheels 62_x and 62_y. Note that g · θb_xy_s · M is an inertial force that cancels the moment due to gravity.

  Then, assuming that the virtual wheels 62_x and 62_y have a radius R_xy, the predicted torque value (hereinafter referred to as torque predicted value) T_xy_exp applied to the virtual wheels 62_x and 62_y is −F_xy · R_xy (= (− Vbdot_xy_s + g · θb_xy_s) · M · R_xy).

  On the other hand, the idling suppression unit 81 uses a map or the like from the previous value ωw_xy_cmd_p of the virtual wheel rotation angular velocity command and the measured value Imot_RL_s of the drive current of the electric motors 31R and 31L, and the torque applied to the virtual wheels 62_x and 62_y. Estimated value (hereinafter referred to as torque estimated value) T_xy_est is obtained. By using the map, it is possible to consider torque loss due to the viscous resistance of the motors 31R and 31L.

  In the following description, when an estimated value of a variable (state quantity) such as the estimated value T_xy_est is represented by a reference symbol, a subscript “_est” is added to the reference symbol of the variable.

  Next, proceeding to STEP 22, the idling suppression unit 81 calculates a torque deviation T_xy_dif (= T_xy_exp−T_xy_est) that is a difference between the estimated torque value T_xy_est calculated in STEP 21 and the predicted torque value T_xy_exp.

  Next, proceeding to STEP 23, the idling suppression unit 81 determines whether the current processing mode is the non-idling mode or the idling mode.

  The non-idling mode is a mode when the wheel body 5 is not idling, the suppression coefficient λ is “1”, and the virtual wheel rotation angular velocity command ωw_xy_cmd is not suppressed. On the other hand, the idling mode is a mode when the wheel body 5 is idling, and the suppression coefficient λ is determined within the range of “0” to “1”, and this suppression coefficient λ is multiplied to determine the virtual wheel rotation angular velocity command. Suppresses ωw_xy_cmd.

  Note that the processing mode (initial processing mode) in a state in which the control unit 50 is initialized when the control unit 50 is started is a non-idling mode.

  The idling suppression unit 81 next executes the processing of STEP24 and the processing of STEP25 respectively in the case where the current processing mode is the non-idling mode and the idling mode in STEP22.

  The processing in the non-idling mode in STEP 24 is executed as shown in the flowchart of FIG. Specifically, the idling suppression unit 81 first satisfies the condition of | T_x_dif |> DV1_x with respect to the torque deviation T_x_dif calculated in STEP 22, and the virtual wheel rotation angular velocity command output from the delay element 81b in STEP 21. Whether or not the condition | ωw_x_cmd_p |> DV2_x is satisfied with respect to the previous value ωw_x_cmd_p is determined in STEP24-1.

  Here, DV1_x is a preset positive value threshold (> 0). And | T_x_dif |> DV1_x means that the torque T_x acting on the virtual wheel 62_x from the electric motors 31R, 31L is estimated from the drive control of the virtual wheel 62_x via the actuator device 7 by the control unit 50. This means that the absolute value of the difference between T_x_est and the predicted value T_x_exp is greater than the threshold value DV1_x. In this situation, the torque applied to the virtual wheel 62_x is contrary to the control by the control unit 50, and the cause may include idling of the virtual wheel 62_x.

  The DV2_x is a preset positive value threshold (> 0). And | ωw_x_cmd_p |> DV2_x means that the absolute value of the previous value ωw_x_cmd_p of the virtual wheel rotation angular velocity command of the virtual wheel 62_x by the control unit 50 via the actuator device 7 is larger than the threshold DV2_x. In this situation, the drive control by the control unit 50 drives the virtual wheel 62_x beyond a predetermined rotational angular velocity. For example, when an external force is applied in the X-axis direction to the vehicle 1 that is stationary or nearly stationary, the virtual wheel 62_x is rotated by the external force, and therefore, the virtual wheel 62_x is regarded as not idle. However, there is a situation where the condition | T_x_dif |> DV1_x is satisfied. Therefore, by adding the condition of | ωw_x_cmd_p |> DV2_x, it is possible to accurately determine that the virtual wheel 62_x may be regarded as idling (hereinafter, referred to as deemed idling). .

  Therefore, the situation in which the determination result in STEP 24-1 is affirmative is a situation in which the virtual wheel 62_x is considered to run idle.

  When the determination result of STEP 24-1 is negative, that is, when it is determined that the virtual wheel 62_x is deemed not to cause idling, the idling suppression unit 81 next executes the determination process of STEP 24-2. . In STEP 24-2, specifically, the idling suppression unit 81 first satisfies the condition | T_y_dif |> DV1_y with respect to the torque deviation T_y_dif calculated in STEP 22, and the virtual output from the delay element 81b in STEP 21. It is determined whether or not the condition | ωw_y_cmd_p |> DV2_y is satisfied with respect to the previous value ωw_y_cmd_p of the wheel rotation angular velocity command.

  Here, DV1_y is a preset positive value threshold (> 0). And | T_y_dif |> DV1_y means that the torque T_y acting on the virtual wheel 62_y from the electric motors 31R and 31L is estimated from the drive control of the virtual wheel 62_y via the actuator device 7 by the control unit 50. This means that the absolute value of the difference between T_y_est and the predicted value T_y_exp is greater than the threshold value DV1_y. In this situation, the torque applied to the virtual wheel 62_y is contrary to the control by the control unit 50, and the idling of the virtual wheel 62_y may be included as the cause.

  The DV2_y is a preset positive value threshold (> 0). And | ωw_y_cmd_p |> DV2_y means that the absolute value of the previous value ωw_y_cmd_p of the virtual wheel rotation angular velocity command of the virtual wheel 62_y by the control unit 50 via the actuator device 7 is larger than the threshold value DV2_y. In this situation, the drive control by the control unit 50 drives the virtual wheel 62_y beyond a predetermined rotational angular velocity. For example, when an external force is applied in the Y-axis direction to the vehicle 1 that is stationary or nearly stationary, the virtual wheel 62_y is rotated by this external force. There is a situation that satisfies the condition of T_y_dif |> DV1_y. Therefore, by adding the condition of | ωw_x_cmd_p |> DV2_x, it is possible to accurately determine that the virtual wheel 62_y is deemed to be idling.

  Therefore, the situation in which the determination result in STEP 24-2 is affirmative is a situation in which the virtual wheel 62_y is considered to be idle.

  The threshold values DV1_y and DV2_y are preferably set to values smaller than the threshold values DV1_x and DV2_x, respectively. Thereby, the sensitivity of the idling detection in the Y-axis direction in which the wheel diameter of the wheel body 5 having a donut shape is small is higher than in the X-axis direction, and the stability of the vehicle 1 can be improved.

  When the determination result of STEP 24-1 or STEP 24-2 is affirmative, that is, when it is determined that at least one of the virtual wheels 62_x and 62_y may cause idling, the idling suppression unit 81 In STEP24-3, 1 is added to the counter value CNT of the increment counter. This increment count is a counter that counts the number of elapsed control processing cycles after detecting the possibility of idling.

  Next, the idling suppression unit 81 determines in STEP 24-4 whether or not the count value CNT of the increment counter is larger than the threshold value DV1_CNT.

  Here, the DV1_CNT is a positive threshold value (> 0) set in advance and is an idling determination count threshold value. CNT> DV1_CNT means that the state where it is determined that there is a possibility of idling has continued for a predetermined time (= Δt · DV1_CNT), and idling It is certain that it has occurred.

  Therefore, if the determination result in STEP23-4 is affirmative, the idling suppression unit 81 resets the count value CNT of the increment counter to “0” in STEP24-5, and sets the processing mode in STEP24-6. The non-idling mode is changed to the idling mode, and the process of FIG.

  On the other hand, if the determination results in STEP 24-1 and STEP 24-2 are negative, the count value CNT of the increment counter is reset to “0” in STEP 24-7, and the processing in FIG. If the determination result in STEP 24-2 is negative, the processing mode is not changed, so that the processing mode is maintained in the non-idling mode even in the next control processing cycle.

  The above is the details of the processing in STEP 24 in the non-idling mode.

  Next, the idling mode process in STEP 25 is executed as shown in the flowchart of FIG. Specifically, the idling suppression unit 81 first determines in STEP 24-1 whether or not the condition | T_x_dif | <DV1_x is satisfied with respect to the torque deviation T_x_dif calculated in STEP 22.

  | T_x_dif | <DV1_x means that the torque T_x applied to the virtual wheel 62_x is estimated from the drive control of the virtual wheel 62_x by the control unit 50 via the actuator device 7 and the predicted value T_x_exp. This means that the absolute value of the deviation T_x_dif is smaller than the threshold value DV1_x. In this case, the estimated torque value T_x_est and the estimated torque value T_x_exp match or substantially match, and the virtual wheel 62_x is considered to be free from idling.

  Therefore, the situation in which the determination result in STEP 25-1 is positive is a situation in which the virtual wheel 62_x is regarded as being less likely to run idle.

  If the determination result in STEP 25-1 is affirmative, that is, if it is determined that the virtual wheel 62_x is considered to be less likely to cause idling, the idling suppression unit 81 next executes the determination process in STEP 25-2. . Specifically, in STEP25-2, the idling suppression unit 81 first determines whether or not the condition | T_y_dif | <DV1_y is satisfied with respect to the torque deviation T_y_dif calculated in STEP22.

  | T_y_dif | <DV1_y means that the torque T_y applied to the virtual wheel 62_y is estimated from the drive control of the virtual wheel 62_y by the control unit 50 via the actuator device 7 and the predicted value T_y_exp. This means that the absolute value of the deviation T_y_dif is smaller than the threshold value DV1_y. In this case, the estimated torque value T_y_est and the predicted torque value T_y_exp match or substantially match, and the virtual wheel 62_y is considered to be less likely to slip.

  If the determination result in STEP 25-2 is affirmative, that is, if it is determined that both the virtual wheels 62_x and 62_y are considered to be less likely to cause idling, the idling suppression unit 81 determines the counter of the increment counter in STEP 25-3. Add 1 to the value CNT. This increment count is a counter that counts the number of elapsed control processing cycles after detecting the possibility of elimination of idling.

  Next, the idling suppression unit 81 determines in STEP 24-4 whether or not the count value CNT of the increment counter is larger than the threshold value DV2_CNT.

  Here, DV2_CNT is a preset positive value threshold (> 0), and is a non-idling (grounding) determination count threshold. And, CNT |> DV2_CNT means that a state in which the virtual wheels 62_x and 62_y are considered to be less likely to run idle continues for a predetermined time (= Δt · DV2_CNT). However, it is certain that idling has been resolved.

  Therefore, if the determination result in STEP23-4 is affirmative, the idling suppression unit 81 resets the count value CNT of the increment counter to “0” in STEP25-5, and the processing mode is changed in STEP25-6. The idling mode is changed to the non-idling mode, and the process of FIG. 16 is terminated.

  On the other hand, if the determination result in STEP 25-1 or STEP 25-2 is negative, the count value CNT of the increment counter is reset to “0” in STEP 25-7, and the process in FIG. If the determination result in STEP 25-1 or STEP 25-2 is negative, the processing mode is not changed, and therefore the processing mode is maintained in the idling mode in the next control processing cycle.

  The above is the details of the idling mode processing of STEP25.

  Returning to the description of FIG. 14, the idling suppression unit 81 determines the suppression coefficient λ to be “1” after executing the processing of the non-idling mode of STEP 24 as described above, and the filter time constant T in the filtering processing of STEP 27. The process of determining is executed in STEP26. In this case, the filter time constant T is determined to be a relatively short time constant Ta, for example, 0.01 seconds.

  On the other hand, the idling suppression unit 81 performs the idling mode processing of STEP 25 as described above, and then determines the suppression coefficient λ within the range of “0” to “1”, and filtering of STEP 28 described later. Processing for determining the filter time constant T in the processing is executed in STEP 27.

  First, the idling suppression unit 81 performs a process of determining the temporary suppression coefficient λ_xy_temp, which is a candidate value of the suppression coefficient λ, in STEP 27-1. Specifically, the idling suppression unit 81 calculates a temporary suppression coefficient λ_xy_temp by the following equations 11x and 11y.

λ_x_temp = A_x · | θb_x_s | + B_x Equation 11x
λ_y_temp = A_y · | θb_y_s | + B_y Equation 11y

Here, A_x and A_y in the expressions 11x and 11y are respectively negative constant values (<0) set in advance, and B_x and B_y are respectively positive constant values (> 0) set in advance. is there. Therefore, the larger the absolute value of the base body tilt angle measurement value θb_xy_s, that is, the greater the tilt of the base body 9, the smaller the provisional suppression coefficient λ_xy_temp, and the base body tilt angle measurement value θb_xy_s is 0, that is, the base body 9 tilts. If not, the temporary suppression coefficient λ_xy_temp is maximum at B_xy.

  A_xy and B_xy are set so that the temporary suppression coefficient λ_xy_temp is “0” when the absolute value of the measured base body tilt angle θb_xy_s is a predetermined angle θth1_xy, for example, θb_x_s is 10 degrees and θb_y_s is 5 degrees. . That is, when the absolute value of the base body tilt angle measurement value θb_xy_s exceeds the predetermined angle θth1_xy, the temporary suppression coefficient λ_xy_temp becomes a negative value (<0). Thus, the absolute value of the base body tilt angle measurement value θb_xy_s at the boundary where the temporary suppression coefficient λ_xy_temp becomes a negative value is larger in the Y-axis direction than in the X-axis direction. Thereby, the sensitivity of the idling detection in the Y-axis direction in which the wheel diameter of the wheel body 5 having a donut shape is small is higher than in the X-axis direction, and the stability of the vehicle 1 can be improved.

  Further, A_xy and B_xy are set so that the temporary suppression coefficient λ_xy_temp is “1” when the absolute value of the base body tilt angle measurement value θb_xy_s is a predetermined angle θth2_xy, for example, θb_x_s is 2 degrees and θb_y_s is 1 degree. . That is, when the absolute value of the measured base body tilt angle θb_xy_s is less than the predetermined angle θth1_xy, the temporary suppression coefficient λ_xy_temp becomes a value exceeding 1 (> 1). Thus, the absolute value of the base body tilt angle measurement value θb_xy_s at the boundary where the temporary suppression coefficient λ_xy_temp is “1” is smaller in the Y-axis direction than in the X-axis direction. Thereby, the sensitivity of the idling detection in the Y-axis direction in which the wheel diameter of the wheel body 5 having a donut shape is small is higher than in the X-axis direction, and the stability of the vehicle 1 can be improved. However, A_xy and B_xy may be set so that the temporary suppression coefficient λ_xy_temp is “1” when the absolute values of the measured base body tilt angle values θb_x_s and θb_y_s are the same predetermined angle, for example, 0 degrees.

  Next, the idling suppression unit 81 performs a process of determining the suppression coefficient λ in STEP 27-2 using the temporary suppression coefficient λ_xy_temp calculated in STEP 27-1. Specifically, the idling suppression unit 81 temporarily determines a smaller value min (λ_x_temp, λ_y_temp) of the temporary suppression coefficients λ_x_temp and λ_y_temp as the suppression coefficient λ. Then, a value obtained through the limiter is determined as the current value of the suppression coefficient λ so that the temporarily determined value of the suppression coefficient λ falls within the range of “0” to “1” (0 <= λ <= 1). In this case, the limiter is for preventing the suppression coefficient λ from being excessively large or small, and if the temporarily determined suppression coefficient λ is in the range of “0” to “1”, The value of the suppression coefficient λ is output as it is as the current value. However, if the temporarily determined suppression coefficient λ is less than “0”, the limiter outputs “0” as the current value of the suppression coefficient λ, and the temporarily determined suppression coefficient λ is “1”. If “1” is exceeded, “1” is output as the current value of the suppression coefficient λ.

  Thus, when the absolute value of the base body tilt angle measurement value θb_x_s is greater than or equal to the predetermined angle θth1_x, or when the absolute value of the base body tilt angle measurement value θb_y_s is greater than or equal to the predetermined angle θth1_y, the current value of the suppression coefficient λ is “ 0 "is determined. When the absolute value of the base body tilt angle measurement value θb_x_s is equal to or smaller than the predetermined angle θth2_x, or when the absolute value of the base body tilt angle measurement value θb_y_s is equal to or smaller than the predetermined angle θth21_y, the current value of the suppression coefficient λ is “1”. It is determined.

  Next, the idling suppression unit 81 executes a process of determining a filter time constant T in a filtering process of STEP 28 described later in STEP 27-3. In this case, the filter time constant T is determined to be a relatively long time constant Tb, for example, 0.1 second.

  And the idling suppression part 81 performs the process (filtering process) which inputs the suppression coefficient (lambda) determined by STEP26 or STEP27 to a filter after performing the process of STEP26 or STEP27 in STEP28.

  Here, the filter for inputting the suppression coefficient λ is to prevent the magnitude of the suppression coefficient λ from changing suddenly stepwise immediately after the processing mode is changed between the idle mode and the non-idle mode. This is a low-pass filter having a first-order lag characteristic. When the processing mode is changed from the idling mode to the non-idling mode, since the filter time constant T determined in STEP 26 is set to a relatively short time constant Ta, the idling mode in which the suppression coefficient λ changes abruptly. In situations other than immediately after changing to the non-idling mode, the output value of the filter matches or substantially matches the suppression coefficient λ, that is, “1”. On the other hand, when the processing mode is changed from the non-idling mode to the idling mode, the filter time constant T determined in STEP 27-3 is set to a relatively long time constant Tb, so the non-idling mode is changed to the idling mode. Even if the suppression coefficient λ changes suddenly, the output value of the filter does not change suddenly.

  The process of STEP28 is executed and the process of FIG.

  The above is the details of the processing of the idling suppression unit 81.

  By the processing of the idling suppression unit 81 described above, the suppression coefficient λ is determined in the following manner.

  For example, if the current processing mode is the non-idle mode, if the determination result in STEP 24-1 or STEP 24-2 is negative, the processing mode is maintained in the non-idle mode, and the suppression coefficient λ is “1”. It is not changed (STEP 26). Therefore, the basic value of the virtual wheel rotation angular velocity command ωw_xy_cmd output from the attitude control calculation unit 80 is input to the motor command calculation unit 82 as it is.

  On the other hand, when the determination result of STEP24-1 and STEP24-2 is negative and the state continues for a predetermined time (= Δt · DV1_CNT) (STEP24-4: YES), the processing mode is changed. Change to idle mode. Then, the suppression coefficient λ is changed in STEP 27, and after being filtered in STEP 28, the suppression coefficient λ is output from the idling suppression unit 81. The suppression coefficient λ output at this time is in the range of “0” to “1”, and the basic of the virtual wheel rotation angular velocity command ωw_xy_cmd output from the attitude control calculation unit 80 according to the value of the suppression coefficient λ. The value is suppressed by the calculation unit 83 and input to the motor command calculation unit 82.

  The value of the suppression coefficient λ determined in STEP 27 is set to be smaller as the absolute value of the base body tilt angle θb_xy is larger. For this reason, the idling can be solved more quickly as the inclination of the base body 9 becomes larger. By the way, since the wheel body 5 has a donut shape, the moving speed of the vehicle 1 is slower in the Y-axis direction than in the X-axis direction. Therefore, the value of the suppression coefficient λ determined in STEP 27 is the base oblique angle in the Y-axis direction, rather than the rate of change | A_x | of the suppression coefficient λ that changes corresponding to the absolute value of the base body tilt angle θb_x in the X-axis direction. The rate of change | A_y | of the suppression coefficient λ that changes corresponding to the absolute value of θb_y is increased. As a result, when the inclination of the base body 9 in the Y-axis direction with a slow movement speed increases, the idling is more quickly eliminated as compared with the case where the inclination of the base body 9 in the X-axis direction with a high movement speed increases. Thus, the vehicle 1 can be stabilized more quickly.

  When the processing mode is the idling mode, the determination result of STEP25-1 and STEP25-2 is affirmative, and the state continues for a predetermined time (= Δt · DV2_CNT) (STEP25). -4: YES), the processing mode is changed to the non-idling mode, and the suppression coefficient λ returns to “1” (STEP 26).

  The above is the details of the calculation processing of the idling suppression unit 81.

  Returning to the description of FIG. 9, the control unit 50 next multiplies the basic value of the virtual wheel rotation angular velocity commands ωw_x_cmd and ωw_y_cmd determined by the attitude control calculation unit 80 by the suppression coefficient λ determined by the idling suppression unit 81. The value is calculated by the calculation unit 83. Then, the control unit 50 inputs the virtual wheel rotation angular velocity commands ωw_x_cmd and ωw_y_cmd, which are suppressed by the calculation unit 83 depending on whether or not idling occurs, to the motor command calculation unit 82, and executes the processing of the motor command calculation unit 82 Thus, the speed command ω_R_cmd of the electric motor 31R and the speed command ω_L_cmd of the electric motor 31L are determined. The processing of the motor command calculation unit 82 is the same as the processing of the XY-RL conversion unit 86b of the limit processing unit 86 (see FIG. 11).

  Specifically, the motor command calculation unit 82 replaces ωw_x, ωw_y, ω_R, and ω_L in the equations 01a and 01b with ωw_x_cmd, ωw_y_cmd, ω_R_cmd, and ω_L_cmd, respectively, and sets ω_R_cmd and ω_L_cmd as unknowns. By solving, the respective speed commands ω_R_cmd and ω_L_cmd of the electric motors 31R and 31L are determined.

  Thus, the vehicle control calculation process of STEP 9 is completed.

  As described above, the control unit 50 executes the control calculation process, so that the attitude of the seat 3 and the base body 9 basically changes in the base body tilt angle deviation in both the riding mode and the self-supporting mode. In a state where both of the measured values θbe_x_s and θbe_y_s are “0” (hereinafter, this posture is referred to as a basic posture), a virtual as an operation amount (control input) is performed so that the vehicle system center of gravity is stationary. A wheel rotation angular acceleration command ωdotw_xy_cmd is determined. When the posture of the seat 3 and the base body 9 is tilted with respect to the basic posture, in other words, the horizontal position of the vehicle system center of gravity (the vehicle / occupant overall center of gravity or the vehicle single body center of gravity) is When the seat 3 and the base body 9 are displaced from a state almost directly above the ground plane, the postures of the seat 3 and the base 9 are restored to the basic posture (θbe_x_s and θbe_y_s are brought close to “0” or held at “0”). And) the virtual wheel rotation angular acceleration command ωdotw_xy_cmd is determined.

  Then, the respective rotational angular velocities of the electric motors 31R and 31L obtained by converting the virtual wheel rotational angular velocity command ωw_xy_cmd obtained by integrating the components of ωdotw_xy_cmd are determined as the speed commands ω_R_cmd and ω_L_cmd of the electric motors 31R and 31L. Further, the rotational speeds of the electric motors 31R and 31L are controlled according to the speed commands ω_R_cmd and ω_L_cmd. As a result, the moving speeds of the wheel body 5 in the X-axis direction and the Y-axis direction are controlled so as to coincide with the moving speed of the virtual wheel 62_x corresponding to ωw_x_cmd and the moving speed of the virtual wheel 62_y corresponding to ωw_y_cmd, respectively. The

  For this reason, for example, if the actual base body tilt angle θb_x shifts forward from the target value θb_x_obj in the direction around the Y axis, the wheel body 5 is adjusted to eliminate the shift (to converge θbe_x_s to “0”). Move forward. Similarly, when the actual θb_x shifts backward from the target value θb_x_obj, the wheel body 5 moves rearward in order to eliminate the shift (to converge θbe_x_s to “0”).

  Further, for example, when the actual base body tilt angle θb_y shifts to the right tilt side from the target value θb_y_obj in the direction around the X axis, the wheel body 5 faces right to eliminate the shift (to converge θbe_y_s to “0”). Move to. Similarly, when the actual θb_y shifts to the left tilt side from the target value θb_y_obj, the wheel body 5 moves to the left in order to eliminate the shift (to converge θbe_y_s to “0”).

  Further, when both the actual base body tilt angles θb_x and θb_y deviate from the target values θb_x_obj and θb_y_obj, respectively, in order to eliminate the shift operation of the wheel body 5 to eliminate the shift of θb_x and the shift of θb_y. And the horizontal movement of the wheel body 5 are combined, and the wheel body 5 moves in the X-axis direction and the Y-axis direction (direction inclined with respect to both the X-axis direction and the Y-axis direction). It becomes.

  In this way, when the postures of the seat 3 and the base body 9 are tilted from the basic posture, the wheel body 5 moves toward the tilted side. Therefore, for example, in the boarding mode, when the occupant intentionally tilts the upper body together with the seat 3 and the base body 9, the wheel body 5 moves to the tilted side. In the present embodiment, for the reasons described later, the movement direction (movement direction in the direction orthogonal to the Z axis) of the vehicle system center of gravity in the horizontal plane when the seat 3 and the base body 9 are tilted from the basic posture, and the wheel The moving direction of the body 5 does not necessarily match.

  When the wheel body 5 is moved (when the entire vehicle 1 is moved), the posture of the seat 3 and the base body 9 is tilted from the basic posture (a posture where the base body tilt angle deviation measurement value θbe_xy_s is constant). When held, the moving speed of the vehicle system center-of-gravity point (and thus the moving speed of the wheel body 5) has a certain deviation from the control target center-of-gravity speed Vb_xy_mdfd, and the deviation depends on the measured base body tilt angle deviation value θbe_xy_s. Converge to the desired moving speed.

  In a situation where Vb_x_mdfd and Vb_x_mdfd are kept at “0”, if the posture of the seat 3 and the base body 9 is held at a constant posture inclined from the basic posture, as described above, The moving speed of the point (and consequently the moving speed of the wheel body 5) converges to a moving speed having a magnitude and direction depending on the measured base body tilt angle deviation value θbe_xy_s.

  Then, the control unit 50 determines the floor reaction force acting on the vehicle 1 from the measured base body tilt angle value θb_xy_s (observed amount related to the tilt posture of the base body 9) and the center of gravity speed estimated value Vb_xy_s (state quantity related to the moving motion of the wheel body 5). F_xy is calculated, and a predicted value T_xy_exp of torque to be applied to the virtual wheel 62_xy when the calculated floor reaction force F_xy is generated is calculated. Further, the control unit 50 is obtained using a map from the previous value ωw_y_cmd_p (target value of the control operation amount) of the determined virtual wheel rotation angular velocity command and the measured value Imot_RL_s of the drive current of the electric motors 31R and 31L. An estimated value T_xy_est of the torque applied to the virtual wheel 62_xy is calculated. Then, the control unit 50 detects the idling of the wheel body 5 based on the torque deviation T_xy_dif that is the difference between the predicted torque value T_xy_exp and the estimated torque value T_xy_est.

  If the wheel body 5 is moving as intended by the control unit 50, there is no difference between the predicted torque value T_xy_exp and the estimated torque value T_xy_est, and the absolute value of the torque deviation T_xy_dif is “0” or the threshold value DV1_xy. Smaller and smaller value. However, when idling occurs in the wheel body 5, the wheel body 5 does not move as intended by the control unit 5, and a difference occurs between the predicted torque value T_xy_exp and the estimated torque value T_xy_est, resulting in a torque deviation. The absolute value of T_xy_dif is larger than the threshold value DV1_xy. Therefore, it is possible to determine the possibility of idling in the wheel body 5 based on the torque deviation T_xy_dif. Accordingly, the idling suppression unit 81 can detect the occurrence of idling of the wheel body 5 based at least on the torque deviation T_xy_dif.

  Furthermore, unlike the slip detection described in the above-mentioned Patent Document 4, it is possible to determine the possibility of idling regardless of the configuration of the moving operation unit. Furthermore, since it is possible to detect the possibility that idling has occurred in the wheel body 5 that affects the floor reaction force F_xy, it is possible to detect idling such as when going straight as well as during turning.

  For example, when an external force is applied to the vehicle 1 that is stationary or nearly stationary, and the wheel body 5 is moved by the external force, the torque deviation T_xy_dif is less than the threshold DV1_xy even if the wheel body 5 is not idling. May be large. Therefore, when the absolute value of the previous value ωw_xy_cmd_p of the virtual wheel rotation angular velocity command is smaller than the threshold value DV2_xy, it is determined that no idling has occurred in the wheel body 5. As a result, it is possible to accurately detect that the wheel body 5 has slipped.

  Here, the correspondence between the vehicle 1 of the present embodiment and the present invention will be supplemented.

  In the present embodiment, the seat 3 (boarding part) corresponds to the mounting part (the mounting part of the occupant as the object to be transported) in the present invention.

  Further, the tilt angle measuring means in the present invention is realized by the tilt sensor 52 and the processing of STEP2 in FIG. In this case, the base body tilt angle measured value θb_xy_s corresponds to the observed value of the tilt posture of the seat 3 as the mounting portion.

  Moreover, the moving operation unit control means in the present invention is realized by the control unit 10, and the processing of STEPs 4 to 10 executed by the control unit 10 corresponds to the control processing in the present invention. The virtual wheel rotation angular acceleration command ωdotw_xy_cmd corresponds to the control operation amount in the present invention.

  Further, the idling suppression unit 81 implements the driving force calculating means, driving force estimating means, and idling detecting means in the present invention. The means for performing the processing of STEP 21 executed by the idling suppression unit 81 corresponds to the driving force calculating means and the driving force estimating means in the present invention, and the means for performing the processing of STEP 22 corresponds to the idling detecting means in the present invention. The predicted torque value T_xy_exp corresponds to the driving force calculated by the driving force calculation means in the present invention, and the estimated torque value T_xy_est corresponds to the driving force estimated by the driving force estimation means in the present invention.

  The front-rear direction corresponds to the first direction in the present invention, and the left-right direction corresponds to the second direction in the present invention. Further, the suppression coefficient λ corresponds to a ratio of approaching “0” from the basic target value of the control operation amount in the present invention.

  Next, some modifications relating to the embodiment described above will be described.

  In the above embodiment, the suppression coefficient λ for the virtual wheel rotation angular velocity commands ωw_x_cmd and ωw_y_cmd is the same, but the present invention is not limited to this. For example, values obtained by performing limiter processing and filtering processing on the temporary suppression coefficients λ_x_temp and λ_y_temp may be used as the suppression coefficients for the virtual wheel rotation angular velocity commands ωw_x_cmd and ωw_y_cmd, respectively.

  In the embodiment, when it is detected that idling occurs only in one of the virtual wheels 62_x and 62_y, the virtual wheel rotation angular velocity command ωw_xy_cmd related to the virtual wheels 62_x and 62_y is suppressed together. It is not limited to this. For example, only the virtual wheel rotation angular velocity command ωw_xy_cmd related to the virtual wheels 62_x and 62_y in which idling has occurred may be suppressed.

  In the above embodiment, the differential value of the center of gravity speed estimated value Vb_xy_s calculated by the equations 05x and 05y and input from the center of gravity speed calculating unit 72 is used in STEP 21, but the speed of gravity instead of the center of gravity speed estimated value Vb_xy_s is used. A value obtained by measuring the center of gravity acceleration with an acceleration sensor may be used instead of the value obtained by measuring the center of gravity speed with a sensor, instead of the differential value of the center of gravity speed estimated value Vb_xy_s.

  Further, in the above-described embodiment, it is assumed that the possibility that idling has occurred in the virtual wheels 62_x and 62_y is detected by comparing the torque deviation T_xy_dif calculated in STEP 22 and the threshold value DV1_xy. However, the present invention is not limited to this. For example, a value obtained by dividing the estimated torque value T_xy_est by the predicted torque value T_xy_exp (= T_xy_est / T_xy_exp) may be compared with a threshold value to detect the possibility of idling in the virtual wheels 62_x and 62_y. Further, the floor reaction force deviation (= T_xy_dif · R_xy) may be compared with a threshold value to detect the possibility that idling has occurred in the virtual wheels 62_x and 62_y.

  Moreover, in the said embodiment, although the vehicle 1 of the structure shown in FIG.1 and FIG.2 was illustrated, the inverted pendulum type vehicle 1 in this invention is not restricted to the vehicle illustrated in this embodiment.

  Specifically, the wheel body 5 as the moving operation unit of the vehicle 1 according to the present embodiment has an integral structure. For example, the wheel body 5 has a structure as shown in FIG. May be. That is, a plurality of rollers are extrapolated on a rigid annular shaft body so that the shaft centers in the tangential direction of the shaft body, and the plurality of rollers are circumferentially arranged along the shaft body. You may comprise a wheel body by arranging in a direction.

  Further, the moving operation unit may have a crawler-like structure as described in FIG.

  Alternatively, for example, as described in FIG. 5 of Patent Document 2, FIG. 7 of Patent Document 3, or FIG. 1 of Patent Document 1, the moving operation unit is configured by a sphere, and the sphere is connected to an actuator device ( For example, the vehicle may be configured to be rotationally driven in the direction around the X axis and the direction around the Y axis by an actuator device having the wheel body 5).

  Moreover, in this embodiment, although the vehicle 1 provided with the seat 3 as the tilting portion was illustrated, the inverted pendulum type vehicle according to the present invention is a step in which an occupant places both feet as shown in FIG. And the vehicle of the structure assembled | attached to the base | substrate by using as a tilting part the part which the passenger | crew who stood up on the step grips may be sufficient.

  Thus, the present invention can be applied to an inverted pendulum type vehicle having various structures as seen in Patent Documents 1 to 3 and the like.

  Furthermore, the inverted pendulum type vehicle according to the present invention includes a plurality of moving operation units that can move in all directions on the floor surface (for example, two in the left-right direction, two in the front-rear direction, or three or more). You may have.

  Further, in the inverted pendulum type vehicle according to the present invention, the tilting portion can be tilted only around one axis (for example, around the left and right axis of the occupant riding the vehicle), and the vehicle is moved in the front-rear direction of the occupant according to the tilting. It may be an inverted pendulum type vehicle.

  In the inverted pendulum type vehicle of the above-described embodiment, the occupant's boarding part (seat) 3 is provided as the tilting part. However, instead of the occupant's boarding part 3, an object to be transported such as luggage is mounted. It may have a mounting portion. In this case, the control process similar to the boarding mode is executed with the transport object mounted on the mounting portion, and the control process similar to the self-supporting mode is performed with the transport object not mounted. It should be executed. Moreover, the vehicle provided with the upper body part etc. of the robot as a tilting part may be sufficient.

  DESCRIPTION OF SYMBOLS 1 ... Inverted pendulum type vehicle, 3 ... Seat (tilting part), 5 ... Wheel body (moving operation part), 7 ... Actuator apparatus, 9 ... Base | substrate, 50 ... Control unit (moving operation part control means), 81 ... Slip suppression Unit (driving force calculation means, driving force estimation means, idling detection means), STEP21 ... driving force calculation means, driving force estimation means, STEP22-28 ... idling detection means.

Claims (4)

A moving operation unit movable on the floor, an actuator device for driving the moving operation unit, a base body on which the moving operation unit and the actuator device are assembled, and a base member on which tilting with respect to the vertical direction is possible. An inverted pendulum type vehicle control device having a tilting part attached thereto,
A target value of a control operation amount that defines a driving force applied to the movement operation unit in order to move the movement operation unit is determined, and according to the determined target value of the control operation amount, A moving operation unit control means for controlling the moving operation via the actuator device;
The floor reaction force acting on the vehicle is calculated from the observed amount relating to the tilt posture of the tilting portion and the state amount relating to the moving motion of the moving motion portion, and when the calculated floor reaction force is generated, Driving force calculating means for calculating the driving force that needs to be applied;
Driving force estimating means for estimating the driving force that defines a target value of the control operation amount determined by the moving unit control means;
An inverted pendulum type comprising: an idling detecting means for detecting the idling of the moving operation unit based on the driving force calculated by the driving force calculating means and the driving force estimated by the driving force estimating means Vehicle control device. In the control apparatus for an inverted pendulum type vehicle according to claim 1,
When the idling detection means detects the occurrence of idling of the moving operation unit, the moving unit control means causes the control operation amount to be closer to “0” than the basic target value. Control device. In the control apparatus for an inverted pendulum type vehicle according to claim 2,
The observed amount related to the tilt posture of the tilting portion includes at least an observed amount of the tilt angle of the tilting portion,
The moving operation unit control means sets the target value of the control operation amount such that the larger the observed amount of the tilt angle of the tilting unit, the larger the ratio of approaching “0” from the basic target value of the control operation amount. A control apparatus for an inverted pendulum type vehicle characterized by determining In the control apparatus of the inverted pendulum type vehicle according to any one of claims 1 to 3,
The moving operation unit is configured to be movable in all directions including a first direction and a second direction perpendicular to each other on the floor surface,
The tilting part is assembled to the base body so as to be tiltable about two axes, an axis around the first direction and an axis around the second direction,
The idling detection means has a reference for detecting the occurrence of idling of the moving operation unit based on the driving force calculated by the driving force calculation means and the driving force estimated by the driving force estimation means. Different from the second direction,
The movement operation unit control means includes a first control operation amount that defines a driving force applied to the movement operation unit to move the movement operation unit in the first direction and the movement operation unit in the second direction. Each of the second control operation amount that defines the driving force applied to the moving operation unit is sequentially determined, and the determined first control operation amount and the second control operation amount are determined. A control apparatus for an inverted pendulum type vehicle, wherein the movement operation of the movement operation unit is controlled according to a set.

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