JP2005138631A - Traveling device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize safe landing even when a wheel is left from a road surface and freely drops off. <P>SOLUTION: When difference of level exists, a floor area becomes narrow at a position of difference of level of a floor. A tire is deformed and variation is generated on a Z axis (traveling position (2)). Further, when the vehicle body is advanced and progresses to a dropping off direction, the tire is further deformed and variation of the Z axis becomes large. Thus, variation of the Z axis is detected to recognize the difference of level and the dropping off state can be previously predicted. Thereby, the wheel rotation speed can be controlled so as to safely carry out landing. Namely, a table attitude angle is varied in the traveling position (2) to damp the traveling speed, but when the traveling speed is large, ZMP rides over the difference of level and comes down. The dropping state can be detected by the rapid variation of an acceleration sensor signal output of the Z axis. When the dropping acceleration [9.8G] is detected by the Z axis acceleration sensor, a motor torque output is made to zero. Thus, when landing is carried out in such a state that the motor torque is made to zero, the tire is freely rotated by reaction force of a contact road surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a traveling device suitable for use in, for example, a vehicle that travels on two wheels with a human being on board, and a control method therefor. Specifically, for example, the regenerative energy generated when the vehicle decelerates or travels on a downhill is efficiently charged so that a favorable travel can be realized.

  For example, a vehicle that travels on two wheels with a human being on board has been proposed (see, for example, Patent Document 1).

US Pat. No. 6,288,505

  For example, the applicant of the present application has previously proposed a traveling apparatus as described below (Japanese Patent Application No. 2003-168224) as a vehicle that travels on two wheels with a human being on board.

  First, an external perspective view of an embodiment of a coaxial two-wheeled vehicle proposed by the present applicant is shown in FIG. In the coaxial two-wheel vehicle 1 shown in FIG. 18, a pair of wheels 3 (a right wheel 3 </ b> R and a left wheel 3 </ b> L) are fixed to both ends of the wheel shaft 2. The wheel 3 is formed of a rubber material having flexible characteristics, and the inside thereof is filled with air, nitrogen gas, or the like. By adjusting the gas pressure to adjust the flexibility of the wheel 3, vibrations of the airframe can be absorbed, and vibrations caused by road surface unevenness and impacts caused by steps can be reduced.

  Further, the wheel shaft 2 includes a base 4 in which a substantially rectangular parallelepiped housing in which a control device or the like to be described later is housed is joined below a plate-like body on which a person rides in a standing posture. It is supported so that it can tilt around. In the following description, it is assumed that the intermediate point of the wheel shaft 2 connecting the two wheels is the origin O of the XYZ coordinate system, passes through this origin O, is parallel to the main surface of the base 4 and is connected to the wheel shaft 2. The vertical direction is defined as the X axis or roll axis, the wheel axis direction passing through the origin O is defined as the Y axis or pitch axis, and the direction passing through the origin O and perpendicular to the main surface of the base 4 is defined as the Z axis or yaw axis. Further, the front of the coaxial two-wheel vehicle 1 is defined as the positive direction of the X axis, the left is defined as the positive direction of the Y axis, and the upper direction is defined as the positive direction of the Z axis.

  As shown in FIG. 19, a motor 10 (10 </ b> R and 10 </ b> L) that can rotate forward and backward is mounted on the base 4, and a rotary encoder 11 that detects the rotational position of the motor 10 is adjacent to the motor 10. (11R and 11L) are provided. Further, a speed reducer 12 (12R and 12L) using a gear or a timing belt is interposed between the motor 10 and the wheel 3, and the rotation of the motor 10 is performed via the speed reducer 12 and a joint (not shown). And transmitted to the wheel 3.

  Further, the base 4 includes a gyro sensor 13 for detecting the angular velocity ωp and ωyaw around the pitch axis and yaw axis of the base 4, and linear accelerations Ax, Ay, Az and pitch axes in the X, Y, and Z axis directions. Various sensors such as an acceleration sensor 14 for detecting angular accelerations αp, αr, αyaw around the roll axis and the yaw axis and a pressure sensor 15 for detecting a load weight on the base 4 are incorporated.

Among these, the pressure sensors 15 are provided at the four corners between the support base 4a and the movable base 4b constituting the plate-like body of the base 4 as shown in the plan view of FIG. 20A and the side view of FIG. 20B. The center of gravity coordinates (Xg, Yg) of the load on the base 4 and the load weight Wg thereof can be detected from the sensor signals of the _four pressure sensors 15 ₁ , 15 ₂ , 15 ₃ , 15 _4. .

That is, when the sensor signals of the pressure sensors 15 ₁ to 15 ₄ are PS ₁ , PS ₂ , PS ₃ , and PS ₄ , and the self-weight applied to the pressure sensors 15 ₁ to 15 ₄ in the no-load state is W ₀ , The weight Wg is obtained as in the following formula (1).

The coordinates of the pressure sensors 15 ₁ , 15 ₂ , 15 ₃ , and 15 ₄ are (X _ps , Y _ps ), (−X _ps , Y _ps ), (−X _ps , −Y _ps ), and (X _ps ), respectively. , −Y _ps ), the barycentric coordinates (Xg, Yg) are obtained as in the following equation (2).

In this equation (2), W ₁₄ represents the weight applied to the pressure sensors 15 ₁ and 15 ₄ in the unloaded state, W ₂₃ represents the weight applied to the pressure sensors 15 ₂ and 15 ₃ in the unloaded state, and W ₁₂ represents W ₃₄ indicates the own weight applied to the pressure sensors 15 ₁ and 15 ₂ in the no-load state, and W ₃₄ indicates the own weight applied to the pressure sensors 15 ₃ and 15 ₄ in the no-load state.

In this way, the load load torque T ₁ due to the load on the base 4 can be calculated by the pressure sensor 15, so that a counter moment is given to the motor 10 to maintain the balance on the base 4 and stabilize the posture. It becomes possible.

  Furthermore, a control device 16 composed of a microcomputer is mounted on the lower housing of the base 4, and various sensor signals and detection signals are input to the control device 16. Based on these input signals, the control device 16 generates motor torque for moving the aircraft forward, backward, and swivel while maintaining the pitch axis angle and yaw axis angle of the base 4 at appropriate values as will be described later. Control.

  Further, as shown in FIG. 21, the coaxial two-wheel vehicle 1 is configured such that the weight center M of the base 4 that can be tilted around the wheel shaft 2 is positioned below the wheel shaft 2. As a result, the position of the center of gravity of the aircraft is kept at the most stable position even when stopped, and it is difficult for the aircraft to fall. In FIG. 21, the height of the upper surface of the base 4 is higher than that of the wheel shaft 2, but the upper surface of the base 4 may be lower than that of the wheel shaft 2.

Here, a control concept for maintaining the posture on the base 4 will be described. As shown in FIG. 22, the load on the base 4, against load induced torque T _1, for example by a human body weight, by controlling the motor torque Tm to generate the same moment, the base 4 is a fulcrum like a seesaw Keep balance in the center. The point corresponding to this balance maintaining point, that is, the point at which the rotational moment about the wheel shaft 2 becomes zero is called ZMP (Zero Moment Point). When this ZMP coincides with the contact point with the road surface of the wheel 3 or when it is within the contact surface with the road surface, the balance is maintained and the posture on the base 4 can be maintained.

When a person with a weight Wh gets on the coaxial two-wheel vehicle 1, the weight center M of the base 4 is tilted about the wheel shaft 2 in accordance with the inclination angle θ of the person as shown in FIG. At this time, the wheel shaft torque T ₀ for balancing the wheel shaft 2 is expressed by the following equation (3), and the motor torque Tm for maintaining the posture is T _{0 when} the reduction ratio of the speed reducer 12 is N: 1. / N.

Thus, in the above-described coaxial two-wheeled vehicle 1, the weight center M of the base 4 is configured to be positioned below the wheel shaft 2 as described above. It is only necessary to add the difference between the moment due to Wh and the moment due to the weight Wm of the base 4 as the wheel shaft torque T ₀ , and the balance can be maintained with a relatively small motor torque.

Further, a dynamic model for maintaining the posture on the base 4 will be described in detail using the XZ coordinate system shown in FIG. Here, for the sake of simplicity, FIG. 24 will be described assuming that there is one wheel 3. Further, the wheel 3, the base 4, and the person on the base 4 are regarded as links, and the center-of-gravity position coordinates are (x ₀ , z ₀ ), (x ₁ , z ₁ ), (x ₂ , z ₂ ), respectively. To do. Further, the mass of each link is m ₀ , m ₁ , m ₂ , and the moment of inertia is I ₀ , I ₁ , I ₂ .

The momentum of the i-th link (i = 0, 1, 2) around the defined point Ω (σ, φ) is expressed by the following formula (4), where the center-of-gravity position coordinates are (x _i , z _i ). Is done. Here, one point given above x and z in Equation (4) indicates that it is the first derivative of x and z.

  Accordingly, the moment due to the inertial force of all links is expressed by the following equation (5). Here, the two points on x and z in the equation (5) indicate the second-order differentiation of x and z. The moment due to gravity of all links is expressed by the following equation (6), where g is the acceleration of gravity.

  The sum of the moment due to the inertial force and the moment due to gravity gives a moment MΩ around the point Ω (σ, φ) as shown in Equation (7).

Excluding the moment due to the gravity of the wheel 3 having the mass m ₀ , the moment MΩ described above becomes the moment Ma around the wheel axis 2 by taking the point Ω (σ, φ) as the origin. The moment Ma about the wheel shaft 2 is expressed by the following equation (8).

If the moment MΩ is expressed using this moment Ma, when x ₀ = 0, that is, when the center of gravity of the wheel 3 is on the wheel shaft 2, the following equation (9) is given.

  Here, ZMP is defined as a point on the floor where the moment MΩ is zero. Therefore, when the height of the wheel shaft 2 is set to h and the coordinates of the ZMP are set to (σzmp, −h) into the formula (7), the following formula (10) is obtained. By solving Equation (10) for σzmp, ZMP can be expressed by link position, acceleration, and mass.

  Further, when the ZMP coordinates (σzmp, −h) are substituted into the above equation (9), the following equation (11) is obtained. In addition, this Formula (11) shows the formula of the balance of the moments around the wheel shaft 2.

  Here, the force acting on the ZMP is illustrated in FIG. In FIG. 25, FN represents a floor reaction force, FT represents a rolling friction force, and F represents a combined vector of FN and FT. Note that the floor reaction force FN is actually distributed over the entire ground contact surface of the wheel 3, but is shown in FIG. From this figure, the formula of the balance of moments about the wheel shaft 2 is expressed as the following formula (12).

  If the following formulas (13) to (15) are substituted into the formula (12), the formula (11) is the same as the above-described formula (11).

In order to stabilize the posture on the base 4, it is only necessary to satisfy σzmp = 0 in the equation (12). That is, if the wheel shaft torque T ₀ = −FT * h is established, the posture can be maintained. Therefore, the posture can be stabilized by controlling the state variable represented by the following formula (16) that satisfies T ₀ = FT = 0.

At this time, x ₀ and x ₁ are uniquely determined by the mechanism structure, but m ₂ , I ₂ , x ₂ , and z ₂ are undefined values because they are human. The moment Mt on the base 4 due to m ₂ , I ₂ , x ₂ and z ₂ is given by the following equation (17). However, the base 4 is assumed to be kept horizontal as shown in FIG.

Here, when the load is a human, the angular velocity ω ₂ is sufficiently small. Therefore, when approximating ω ₂ ≈0, the moment Mt is zero when x ₂ and its second-order differential value are zero in the equation (18). become. that the x ₂ and its second-order differential value to zero, may be considered equivalent to load induced torque T ₁ of the on the base 4 to control the x ₀ and x ₁ such that zero. Further, moment Mt by the load induced torque T ₁ is equivalent to act on the point on the base 4 (xf, L) with a force F2. Therefore, if x ₀ and x ₁ that make xf zero can be given, T ₁ = 0, and the condition for maintaining a stable posture can be satisfied.

As shown in FIG. 26, when it is controlled so as to keep the x _{0 =} x ₁ by feedback controlled gyro sensor signal on the base 4 gives the motor torque Tm, the motor such that xf = x ₀ The posture can be kept stable by controlling the torque Tm.

Specifically, when the error _{Ef = xf-x 0, Ef} > a x ₀ if 0 to advance the machine body of the motor torque Tm to be displaced in the positive direction as negative, if Ef <0 the motor torque Tm to displace the x ₀ in the negative direction by retracting the fuselage as positive, it is possible to converge the error Ef to zero. That is, A ₀ is a positive constant, the Ef by giving the motor torque Tm to be Tm = -A 0 * _Ef is converged to zero, it is possible to maintain the posture stability.

Actually, for example, when the base 4 is tilted about the pitch axis by an angle θ ₀ as shown in FIG. 27, a load load torque of T ₁ (= Mτ × L) is generated by a person with a weight M, so that load load By controlling the motor torque Tm so as to give the wheel shaft torque T ₀ in the opposite direction to the torque T ₁ , ZMP can be made to coincide with the ground contact point of the wheel 3 and the posture can be kept stable.

Here, when a person rides on the base 4, although there is an individual difference, the force applied to the sole is usually changed in order to maintain the posture in a cycle of 1 to 2 seconds. torque T ₁ is changed to the uncertainty. Therefore, it is necessary to add torque that can be balanced in real time to the motor 10 to keep the angle of the base 4 constant with respect to load fluctuations.

Therefore, the above-described coaxial two-wheel vehicle 1 has a control mechanism as shown in FIG. 28 in the control device 16 in order to cancel such load fluctuations in real time. In FIG. 28, the subtracter 20 takes a deviation between the base angle command θref, which is an attitude command, and the current base angle θ ₀ detected by the gyro sensor 13 and the acceleration sensor 14, and supplies this deviation to the attitude controller 21. Is done. Posture controller 21 calculates the motor torque current value Tgyr [A] from the base angle command θref and current base angle theta ₀ Prefecture.

Further, the regulator 22 estimates the load load torque T ₁ using the sensor signals PS ₁ , PS ₂ , PS ₃ , PS ₄ of the pressure sensor 15 and cancels the estimated load load torque current value T _1. '/ Km [A] is calculated. Here, Km is a motor constant [Nm / A]. When the barycentric coordinates of the load are (Xg, Yg) and the load weight is Wg, the estimated load load torque T ₁ ′ is given by the following equation (18).

Then, the subtracter 23 takes a deviation between the motor torque current value Tgyr and the estimated load load torque current value T ₁ ′ / Km, and this deviation is given to the motor 24 as the motor current I [A]. Motor 24 the motor torque Tm generated by the rotation by the motor current I, the adder 25 and transmitted to the base 26 and the motor torque Tm and the load induced torque T ₁ is being added.

Thus, by adding the motor torque Tm to cancel the load induced torque T ₁ to the motor 24, at the time of stopping it can be kept constant base angle to the load fluctuation.

  Although the posture stability control can be performed by the above control mechanism, in order to travel in this state, a control mechanism for travel control is further required. Therefore, the above-described coaxial two-wheel vehicle 1 actually has a two-wheel structure control mechanism that independently obtains motor torque for posture stability control and motor torque for travel control.

  A physical model of such a two-wheel structure control mechanism is shown in FIG. In FIG. 29, for the sake of simplicity, description will be made assuming that there is one wheel 3. As shown in FIG. 29, various sensors such as a gyro sensor 13, an acceleration sensor 14, and a pressure sensor 15 are built in the base 4, and a motor stator 30, a rotary encoder 31, and a motor rotor 32 are present below the base 4. The rotation of the motor rotor 32 is transmitted to the wheel 3 via the speed reducer 33 and the joint 34.

The posture controller / adjuster 40 includes a base angle command θref that is a posture command, the current base angle θ ₀ detected by the gyro sensor 13 and the acceleration sensor 14, and sensor signals PS ₁ , PS ₂ , PS ₃ , The motor torque Tgyr and the estimated load load torque T ₁ ′ described above are calculated from PS ₄ . Further, the motor controller 41 calculates a motor torque for traveling from the rotational position command Pref of the motor rotor 32 that is a traveling command and the current rotational position θr of the motor rotor 32 detected by the rotary encoder 31.

The adder 42 adds the motor torque Tgyr and the estimated load load torque T ₁ ′ and the motor torque for traveling, and supplies the added value to the motor rotor 32.

  Here, the base angle command θref described above is a target value of the base angle that is set according to the acceleration Ax in the X-axis direction so that the passenger can ride stably. Specifically, the base 4 is horizontal when the X-axis acceleration Ax is zero, and the base 4 is tilted forward when the X-axis acceleration Ax is negative. Each is set to tilt backward.

  Therefore, for example, when the X-axis acceleration Ax is positive, as shown in FIG. 30, if the base 4 is tilted so that the ZMP is positioned in the direction of the combined vector of the inertial force and gravity, the occupant maintains a stable posture. be able to. The base angle command θref changes in proportion to the X-axis acceleration Ax.

A block diagram of the control mechanism is shown in FIG. In the subtracter 50, a deviation between the base angle command θref, which is an attitude command, and the current base angle θ ₀ detected by the gyro sensor 13 (and the acceleration sensor 14) is taken, and this deviation is supplied to the attitude controller 51. . Attitude controller 51, the motor torque Tgyr calculated from the base angle command θref and current base angle theta ₀ Prefecture, supplies the motor torque Tgyr the adder 54.

  On the other hand, the subtracter 52 takes a deviation between the rotational position command Pref of the motor rotor 57 that is a running command and the current rotational position θr of the motor rotor 57 detected by the rotary encoder 58, and this deviation is supplied to the motor controller 53. The The motor controller 53 calculates a motor torque for traveling from the rotational position command Pref and the current rotational position θr, and supplies the motor torque to the adder 54.

When the load torque T ₁ is applied to the base 4, sensor signals PS ₁ , PS ₂ , PS ₃ , PS _{4 of} the pressure sensor 15 are supplied to the adjuster 55, and the adjuster 55 is based on this sensor signal. The estimated load load torque T ₁ ′ described above is calculated.

The adder 54 adds the motor torque Tgyr from the attitude controller 51 and the motor torque from the motor controller 53, and the subtracter 56 subtracts the estimated load load torque T ₁ ′ from this added value. This becomes the final motor torque Tm and is given to the motor rotor 57. In the adder 59, the reaction force of the motor torque Tm and the load induced torque T ₁ is is added, the sum is given to the motor stator / base 60.

  The rotation of the motor rotor 57 is controlled according to the motor torque Tm. The rotational position θr of the motor rotor 57 is converted to 1 / N by the reducer 61 having a reduction ratio N: 1 and transmitted to the wheels 3. That is, the rotational position θw of the wheel 3 is 1 / N of the rotational position θr of the motor rotor 57. The rotary encoder 58 detects the rotational position θr of the motor rotor 57 and supplies a detection signal to the subtractor 52.

On the other hand, the motor stator / base 60, as described above, although the added value of the reaction force of the motor torque Tm and the load induced torque T ₁ is applied, since they are canceled each other, the tilting of the motor stator / base 60 Is suppressed.

FIG. 32 represents the process in the block diagram shown in FIG. 31 as a mathematical model using a Laplace operator. As described above, the posture controller 51, given a deviation between the base angle command θref and current base angle theta ₀ is, the motor controller 53, the rotational position command Pref of the motor rotor 57 and the current rotational position θr Deviation is given. In the attitude controller 51 and the motor controller 53, each motor torque is calculated by feedback control that performs, for example, PID (proportional / integral / derivative) calculation.

That is, Kp ₀ and Kp ₁ are proportional gains, Ki ₀ and Ki ₁ are integral gains, and Kd ₀ and Kd ₁ are differential gains. With these control gains, the followability of the motor responding to the attitude command θref and the travel command Pref changes. For example, when the proportional gains Kp ₀ and Kp ₁ are reduced, the motor rotor 57 moves with a slow follow-up delay, and when the proportional gains Kp ₀ and Kp ₁ are increased, the motor rotor 57 follows at high speed. In this way, by changing the control gain, it is possible to adjust the attitude command θref, the travel command Pref, the magnitude of the actual motion error, and the response time.

The motor rotor 57 is given a motor torque Tm obtained by subtracting the estimated load load torque T ₁ ′ from the sum of the motor torque from the attitude controller 51 and the motor torque from the motor controller 53, and the rotation angle θr. Only rotate. Here, Jr is an inertia of the motor rotor 57, and Dr is a viscous resistance (damper coefficient) of the motor rotor 57.

On the other hand, the motor stator / base 60, but the sum of the reaction force of the motor torque Tm as described above and load induced torque T ₁ is applied, they are suppressed tilted because it is canceled out with each other. Here, J is the inertia of the motor stator / base 60, and D is the viscous resistance (damper coefficient) of the motor stator / base 60.

More specifically, the mathematical model shown in FIG. 32 is as shown in FIG. As shown in FIG. 33, the posture controller 70 generates a motor torque Tgyr for attitude control by performing PID control on the difference between the base angle command θref and current base angle theta _0, the motor control The device 71 generates motor torque for travel control by performing PID control on the deviation between the rotational position command Pref of the motor 10 and the current rotational position θr.

Further, the adjuster 72 generates an estimated load load torque T ₁ ′ from the sensor signal of the pressure sensor 15. The adder 73 adds these torques and gives the obtained motor torque Tm to the motor 10. The motor 10 is rotationally driven by the motor torque Tm, and the rotation is converted to 1/16 by the reducer 74 having a reduction ratio of 16: 1 and transmitted to the wheels 3.

  As described above, in FIG. 29 to FIG. 33, for the sake of simplicity, it has been described that there is one wheel 3. However, in the actual coaxial two-wheeled vehicle 1 having the left and right wheels 3 </ b> R and 3 </ b> L, for example, the attitude controller 51 in FIG. While used in common by the left and right wheels 3R, 3L, a motor controller 53 is provided independently on the left and right.

  A block diagram of the control mechanism in this case is shown in FIG. The sensor value ωp from the gyro sensor 13 is sent to the angle calculator 82 via a bandpass filter (BPF) 80 having a pass band of 0.1 to 50 Hz, for example, and the sensor value αp from the acceleration sensor 14 is, for example, a cutoff frequency Is sent to the angle calculator 82 via a low-pass filter (LPF) 81 of 0.1 Hz. The angle calculator 82 calculates the current base angle θ0 based on these sensor values.

Further, the subtractor 83 takes a deviation between the base angle command θref, which is a posture command, and the current base angle θ _0, and this deviation is supplied to the posture controller 84. Posture controller 84 from the base angle command θref and current base angle theta ₀ Prefecture, calculates a motor torque Tgyr described above.

  On the other hand, the subtractor 85R takes a deviation between the rotational position command Prefr of the motor rotor 92R, which is a travel command for the right wheel 3R, and the current rotational position θr of the motor rotor 92R detected by the rotary encoder 93R, and this deviation is proportional to the position. It is supplied to the controller 86R. The position proportional controller 86R performs position proportional (P) control on this deviation and supplies the proportional control result to the subtractor 87R.

  The differentiator 88R differentiates the rotational position θr of the motor rotor 92R supplied from the rotary encoder 93R, and supplies the differentiation result to the subtractor 87R. In the subtractor 87R, the deviation between the proportional control result from the position proportional controller 86R and the differential result from the differentiator 88R is taken, and this deviation is supplied to the speed proportional controller 89R. The speed proportional controller 89R performs speed proportional (P) control on this deviation, and supplies the proportional control result to the adder 90R.

In the adder 90R, the proportional control result, the motor torque Tgyr, and the estimated load load torque T ₁ ′ obtained from the sensor signals PS ₁ , PS ₂ , PS ₃ , PS ₄ of the pressure sensor 15 in the adjuster 94 are added. The added value is supplied to the current control amplifier 91R. The current control amplifier 91R generates a motor current based on the added value and drives the motor rotor 92R. The rotational position of the motor rotor 92R is supplied to the differentiator 88R together with the subtractor 85R. Since the same applies to the left wheel 3L, the description thereof is omitted.

  Thus, the above-described coaxial two-wheel vehicle 1 has a control mechanism for posture stability control common to the left and right wheels 3R and 3L and a control mechanism for independent left and right travel control, and these perform independent control. Therefore, it is possible to achieve both stable posture control and traveling control in a stable manner.

  Next, speed control in the above-described coaxial two-wheel vehicle 1 will be described.

As described above, in the coaxial two-wheel vehicle 1 described above, the load on the base 4 is detected from the sensor signals PS ₁ , PS ₂ , PS ₃ , PS _{4 of the four} pressure sensors 15 ₁ to 15 4 provided at the four corners of the base 4. The barycentric coordinates (Xg, Yg) and the load weight Wg thereof are detected to obtain the load load torque T1, and the barycentric coordinates (Xg, Yg) are further used as a direction and speed control command. Specifically, when the load weight Wg is equal to or greater than a predetermined value, the speed command Vx is changed based on the X coordinate Xg of the center of gravity position.

This is shown in FIG. In Figure 35, where a range from X ₃ to X ₁ is stopping area, the command speed to zero within this range. This stop area is preferably the X coordinate range of the contact surface with the road surface of the wheel 3. In this case, for example, when the load weight Wg is large or when the gas pressure of the wheel 3 is low, the contact area with the road surface of the wheel 3 increases, so the range of the stop region also increases. By providing the stop region (dead zone) in this way, the aircraft can be prevented from moving forward and backward due to a slight center of gravity movement unintended by the passenger.

If X-coordinate is X ₁ or more, until it reaches the maximum forward speed SFmax, command speed is increased in accordance with the magnitude of the X coordinate. Further, X-coordinate is forcibly decelerate to a stop becomes X ₂ or more, and stops until stabilizing the posture at the stop area again. Thus, by providing the area where the vehicle is forcibly decelerated and stopped, the safety of the passenger when traveling at the maximum speed can be ensured.

Similarly, when the X coordinate is X ₃ below, until reaching the retracted maximum speed SB max, the command speed is increased in accordance with the magnitude of the X coordinate. The maximum reverse speed SbMAX is preferably smaller than the maximum forward speed SfMAX. Further, X-coordinate is forcibly decelerate to a stop becomes X ₄ below, to stop until stabilizing the posture at the stop area again.

X coordinate from _{X 1} to _{X 2,} or in the period from _{X 3} to _{X 4,} in accordance with the X-coordinate Xg, for example, by the following equation (19), the rotation of the rotational position command Prefr the motor 10L of the motor 10R A position command Prefl is generated. Here, in Expression (19), G ₀ is a positive constant gain, and can be varied according to, for example, the load weight Wg.

When the speed command at time t = 0 is Vx ₀ and the speed command at time t = t ₁ is Vx ₁ , the acceleration is continuously changed so as not to cause mechanical resonance vibration. It is preferable to travel. In this case, assuming that the time required to reach Vx ₁ is Δt, the traveling speed command Vref (t) at time t (0 ≦ t ≦ t ₁ ) can be calculated by the following equation (20), for example. .

At this time, the rotational position command Pref (t) of the motor 10 is a value obtained by integrating the traveling speed command Vref (t) of the equation (20), and is given by a quintic function as shown in the following equation (21). Here, in Expression (21), Pref ₀ is a rotational position command at time t = 0.

In addition to forward / backward movement, when the load weight Wg is equal to or greater than a predetermined value, the turning speed command Vr can be changed based on the Y coordinate Yg of the center of gravity position, for example, as shown in FIG. Here, in FIG. 36, a range from −Y ₁ to Y ₁ is a stop region, and the command turning speed is set to zero within this range.

This stop area can be arbitrarily set in the vicinity of the origin O. By providing the stop region (dead zone) in this way, it is possible to prevent the aircraft from turning due to a slight center of gravity movement that is not intended by the passenger. When the Y coordinate becomes Y ₁ or more, the command turning speed increases according to the size of the Y coordinate until the clockwise maximum speed CWMAX is reached. Similarly, when the Y coordinate becomes −Y ₁ or less, the command turning speed increases according to the magnitude of the Y coordinate until the counterclockwise maximum speed CCWMAX is reached.

When the Y coordinate is Y ₁ or more or −Y ₁ or less, a rotational position command Rrefr of the motor 10R and a rotational position command Rrefl of the motor 10L are generated according to the Y coordinate Yg. When the traveling speed is zero, the rotational position command Rrefr of the motor 10R and the rotational position command Rrefl of the motor 10L are antiphase commands as shown in the following formula (22), for example. Here, in the formula (22), G ₁ is a positive constant gain may be variable in accordance with the example the load weight Wg.

  On the other hand, when the traveling speed is not zero, the rotational position command Rrefr of the motor 10R and the rotational position command Rrefl of the motor 10L are in-phase commands as shown in the following equations (23) and (24), for example. Here, in the equations (23) and (24), G2 is a positive constant gain, and can be varied according to the load weight Wg, for example.

  Here, when traveling on uneven road surfaces such as uneven road surfaces and inclined road surfaces, it becomes difficult to travel in the target direction given by the rotational position commands of the left and right motors 10R, 10L. There is a risk of deviation in the traveling direction. Further, even when the effective diameter of the wheel 3 is different due to the difference in gas pressure between the left and right wheels 3R, 3L, there is a possibility that the target direction and the actual traveling direction are similarly shifted.

  Therefore, in the above-described coaxial two-wheeled vehicle 1, the actual traveling direction is detected by the gyro sensor 13 that detects the angular velocity ωyaw around the yaw axis, and the rotational speeds of the left and right motors 10R and 10L are independently controlled, thereby obtaining the target direction. Eliminate deviations from the actual direction of travel.

As an example, the effective diameter of the left wheel 3L is shorter than the right wheel 3R as shown in A of FIG. 37, and ωyaw _{1 is used} as a gyro sensor signal around the yaw axis when going straight as shown in B of FIG. A case where [rad / sec] is detected will be described. In such a case, when the average of the rotational speed commands Vrefr and Vrefl is Vref ₀ , the rotational speed commands Vrefr and Vrefl to be given to the left and right motors 10R and 10L as shown in the following equations (25) and (26). By correcting the above, the aircraft can be moved straight. Here, in Formulas (25) and (26), K ₀ is a positive constant.

  Further, when Dref [rad / sec] is given as the target direction as shown in FIG. 37C, the rotational speed command Vrefr is applied to the left and right wheels as shown in the following equations (27) and (28). , Vrefl is given.

  The rotational speed commands Vrefr and Vrefl thus obtained are converted into wheel rotational position commands Prefr and Prefl by the following equations (29) and (30), respectively. Here, in Expressions (29) and (30), k is an integer representing the number of samplings, and Pref (k) indicates a rotational position command in k sampling.

  Similarly, when turning, there is a possibility that the turning speed may be shifted due to a difference in gas pressure between the left and right wheels 3R and 3L, a difference in road surface conditions, and the like. Also in this case, the actual turning speed is detected by the gyro sensor 13 that detects the angular velocity ωyaw around the yaw axis, and the rotational speeds of the left and right motors 10R and 10L are independently controlled, so that the target turning speed and the actual turning speed can be determined. The deviation from the turning speed of can be eliminated.

As an example, the case where the effective diameter of the left wheel 3L is shorter than the right wheel 3R and ωyaw ₂ [rad / sec] is detected as a gyro sensor signal around the yaw axis when turning will be described. If the signals obtained by differentiating the rotational position command Rrefr of the right wheel 3R and the rotational position command Rrefl of the left wheel 3L are respectively Vrefr and Vrefl, the turning speed error ωerr is expressed by the following equation (31).

In this case, as shown in the following equations (32) and (33), the airframe can be turned as intended by correcting the rotational position commands Rrefr and Rrefl given to the left and right motors 10R and 10L. Here, equation (32), in (33), _{G 3} is a positive constant gain may be variable in accordance with the example the load weight Wg.

  Thus, in the above-described coaxial two-wheeled vehicle 1, the actual traveling direction and turning speed are detected by the gyro sensor 13 that detects the angular velocity ωyaw around the yaw axis, and the rotational speeds of the left and right motors 10R and 10L are independently controlled. Thus, the deviation between the target direction (turning speed) and the traveling direction (turning speed) can be eliminated.

  Further, the software configuration of the coaxial two-wheel vehicle 1 will be described with reference to FIG. As shown in FIG. 38, the hardware layer 150 in the lowest layer is formed in a hierarchical structure including the kernel layer 151, the on-body layer 152, the network layer 153, and the application layer 154 in the highest layer. The

  The hardware layer 150 is a circuit hierarchy, and includes, for example, a motor control circuit, a central control circuit, a sensor circuit control circuit, and the like. The kernel layer 151 is a layer that performs various calculations such as motor servo calculation, attitude control calculation, traveling control calculation, or real-time traveling target value calculation. In the hardware layer 150 and the kernel layer 151, basic attitude stabilization control and traveling control are realized. The on-body layer 152 is a layer that performs a travel target value calculation, an obstacle avoidance trajectory generation, and the like.

  Each of these hierarchies is executed with a different sampling control cycle, and the cycle becomes longer as the upper hierarchies. For example, in the hardware layer 150 of the lowest layer, the control cycle is as short as 0.1 msec, whereas in the kernel layer 151, the control cycle is as long as 1 msec and on-body layer 152 is 10 msec. .

Next, the overall circuit configuration of the coaxial two-wheel vehicle 1 will be described. As shown in FIG. 39, the sensor circuit 200, the sensor signals PS1 from the pressure sensor _{15 1 ~15 4, PS2, PS3} , PS4 is supplied. In addition to this sensor signal, the sensor circuit 200 detects sensor signals ωp, ωyaw from the gyro sensor 13 that detects angular velocities around the pitch axis and the yaw axis, linear acceleration in the X, Y, and Z axis directions, pitch axis, roll The sensor signals Ax, Ay, Az, αp, αr, αyaw from the acceleration sensor 14 that detects the angular acceleration around the axes and the yaw axes are combined and supplied to the control device 16.

  Based on these sensor signals, the control device 16 generates the motor torque Tgyr and the rotational position command Pref of the motor rotor, which is a travel command, as described above, and supplies these to the left and right motor drivers 203R and 203L. The motor drivers 203R and 203L calculate the optimum motor current for driving the motors 10R and 10L of 200 W, for example, based on the motor torque Tgyr, the rotational position command Pref of the motor rotor, and the like, and supply them to the motors 10R and 10L. . The rotational positions of the motors 10R and 10L are obtained by the rotor encoders 11R and 11L and fed back to the motor drivers 203R and 203L.

  The servo-on / power switch 204 is connected to the control device 16 and the power switch 205, and a signal from the power switch 205 is supplied to the power management circuit 206. The power management circuit 206 is connected to the battery 207 and supplies control power of 24V to the control device 16, the audio processing circuit 201, and the image processing circuit 202, and also supplies motor power to the motor drivers 203R and 203L. . The power management circuit 206 is supplied with regenerative power of the motors 10R and 10L via the motor drivers 203R and 203L, and the power management circuit 206 charges the battery 207 using this regenerative power.

A detailed internal configuration of the overall configuration shown in FIG. 39 will be described with reference to FIG. As shown in FIG. 40, the sensor circuit 200, the sensor signals PS1 from the pressure sensor _{15 1 ~15 4, PS2, PS3} , PS4, the gyro sensor ₁₃ 1, 13 ₂ sensor signals from .omega.p, Omegayaw, the acceleration sensor 14 Sensor signals Ax, Ay, Az, αp, αr, αyaw are supplied. The sensor circuit 200 adjusts the gain of the sensor signals PS1, PS2, PS3, and PS4 from the pressure sensor 15 with a pressure gain of, for example, 10 mv / N, and further converts them into digital signals via an analog-digital converter (not shown). This is supplied to the center-of-gravity calculation unit 210 of the control device 16.

The sensor circuit 200, the gyro sensor ₁₃ 1, 13 ₂ sensor signals from .omega.p, with gain adjustment in a position gain of the example 1.6V / (rad / sec) ωyaw , sensor signals Ax from the acceleration sensor 14, Ay, Az, αp, αr, and αyaw are gain-adjusted with a posture gain of, for example, 1.6 V / (rad / sec ² ), converted into a digital signal via an analog-digital converter (not shown), and then subjected to signal preprocessing. To the unit 211. The signal preprocessing unit 211 performs preprocessing such as applying a digital filter to the input signal, or calculating an offset adjustment or a posture position, that is, a base angle θ0.

The center-of-gravity calculation unit 210 is based on the sensor signals PS1, PS2, PS3, and PS4 from the pressure sensors 15 ₁ to 15 ₄ as described above, and the center-of-gravity position coordinates (Xg, Yg) of the load on the base 4 and its load weight Wg. The center of gravity position coordinates (Xg, Yg) and the load weight Wg information are supplied to the travel command calculator 212, and the center of gravity position Y coordinate Yg and the load weight Wg information are supplied to the turn command generator 215. Supply.

  For example, the travel command calculator 212 generates a speed command Vx based on the center-of-gravity position X coordinate-travel speed characteristic as shown in FIG. 35, and the rotational speed command generator 213 is based on the speed command Vx. A rotation speed command Vref (t) is generated by performing a next function calculation. The rotational speed command generator 213 supplies the rotational position command Pref (t) to the rotational position command generator 214, the turning command generator 215, and the attitude command generator 216.

  The turning command generator 215 includes the Y coordinate Yg and the load weight Wg of the center of gravity supplied from the center of gravity calculating unit 210, the rotational angular velocity ωyaw about the yaw axis supplied from the signal preprocessing unit 211, and the rotational speed command generator 213. A phase command for turning, for example, Yg * G1, is generated based on the rotational speed command Vref (t) supplied from, and this phase command is supplied to the rotational position command generator 214.

  The rotational position command generator 214 integrates the rotational speed command Vref (t) supplied from the rotational speed command generator 213 to generate a rotational position command Pref (t), and sends the rotational position command Prefr ( t), Prefl (t) is supplied. At this time, the rotational position command generator 214 generates rotational position commands Prefr (t) and Prefl (t) in consideration of the phase command from the turning command generator 215.

  The attitude command generator 216 calculates a base angle command θref which is an attitude command based on the rotation speed command Vref (t) supplied from the rotation speed command generator 213 as described with reference to FIG. The angle command θref is supplied to the subtracter 217. The subtractor 217 subtracts the current base angle θ 0 obtained by the signal preprocessing unit 211 from the base angle command θref, and supplies the deviation to the attitude controller 218. The attitude controller 218 performs PID control based on this deviation to obtain the motor torque Tgyr.

  When performing PID control, the PI gain may be changed according to the load weight Wg on the base 4. Specifically, it is preferable to increase the proportional gain and decrease the integral gain when the load weight Wg increases. The attitude control unit 218 supplies the motor torque Tgyr to the left and right motor drivers 203R and 203L.

  In the motor driver 203R for the right wheel 3R, the subtractor 230R takes a deviation between the rotational position command Prefr, which is a traveling command for the motor 10R, and the current rotational position θr of the motor 10R detected by the rotary encoder 11R. The deviation is supplied to the position proportional controller 231R. The position proportional controller 231R performs position proportional (P) control on this deviation, and supplies the proportional control result to the subtractor 232R. The differentiator 233R differentiates the rotational position θr of the motor 10R supplied from the rotary encoder 11R, and supplies the differentiation result to the subtractor 232R.

  The subtractor 232R takes a deviation between the proportional control result from the position proportional controller 231R and the differential result from the differentiator 233R, and this deviation is supplied to the speed proportional / integral controller 234R. The speed proportional / integral controller 234R performs speed proportional / integral (PI) control on this deviation, and supplies the proportional / integral control result to the adder 235R. The adder 235R adds the proportional / integral control result and the motor torque Tgyr, and supplies the added value to the current control amplifier 236R.

  The current control amplifier 236R generates a motor current based on the added value, and drives the 200W motor 10R, for example. The rotational position of the motor 10R is supplied to the differentiator 233R together with the subtractor 230R. Since the same applies to the left wheel 3L, the description thereof is omitted.

  The power management circuit 206 is connected to, for example, a 24V battery 207, supplies 24V and 1A control power to the control device 16, and supplies 24V and 30A motor power to the motor drivers 203R and 203L, respectively. The power management circuit 206 is supplied with regenerative power of the motors 10R and 10L via the motor drivers 203R and 203L, and the power management circuit 206 charges the battery 207 using this regenerative power.

  As described above, in the coaxial two-wheeled vehicle 1 previously proposed by the present inventor, the motor torque Tgyr for controlling the angle of the base 4 using the gyro sensor 13 and the acceleration sensor 14 and the load load torque using the pressure sensor 15. A posture controller common to the left and right wheels 3R and 3L, and a left and right independent motor controller that generates motor torque for running control using the pressure sensor 15. Since they are provided and perform independent control, it is possible to achieve both stable posture control and stable travel control.

  Moreover, in the coaxial two-wheeled vehicle 1 previously proposed by the inventor of the present application, traveling control is performed according to the center of gravity coordinates of the load on the base 4, but stops in the X coordinate range and the Y coordinate range of the ground contact surface with the road surface of the wheel 3. Since the area (dead zone) is provided, the aircraft can be prevented from moving forward, backward, and turning due to a slight movement of the center of gravity that is not intended by the passenger.

Further, in the coaxial two-wheeled vehicle 1 previously proposed by the present inventor, the actual traveling direction and turning speed are detected by the gyro sensor 13 that detects the angular velocity ωyaw around the yaw axis, and the rotational speeds of the left and right motors 10R and 10L are independent. By controlling to, the deviation between the target direction (turning speed) and the traveling direction (turning speed) can be eliminated.
The applicant of the present application has previously proposed a traveling device using such a coaxial two-wheeled vehicle.

  Incidentally, for example, in the traveling device shown in Patent Document 1 described above, the occupant travels by changing the posture of the center of gravity based on the control principle of the inverted pendulum. For this reason, when the vehicle travels on a road surface with a large level difference and the wheel falls free from the road surface in the air, the wheel rotates at a high speed by the control device. When the wheels rotated at high speed land on the road surface, the aircraft suddenly travels and the posture becomes unstable, and there is a problem that the passenger falls over without being able to maintain the posture and becomes in a dangerous state.

  On the other hand, the coaxial two-wheeled vehicle 1 previously proposed by the inventor described above is a device that freely changes the direction only by the balance of the center of gravity of a human. In this case, various sensors are provided to measure the movement of the center of gravity, and it is possible to detect the state in which the vehicle is freely falling using these sensors.

  This application has been made in view of the above points, and the problem to be solved is that the conventional apparatus travels on a road surface with a large step and the wheels are free-falling in the air away from the road surface. If the wheel is rotated at high speed by the control device, the aircraft will suddenly run and the posture becomes unstable when the wheel that has rotated at high speed lands on the road surface, and the passenger falls over without maintaining the posture and is in a dangerous state There was a risk of becoming.

  Therefore, in the present invention, the road surface step is predicted by the change of the acceleration sensor in the gravity direction (Z-axis) of the aircraft, and the rotation of the wheel is controlled with respect to the state of falling from the step. According to the above, even when the vehicle travels on a road surface having a large level difference and the wheels are free from the road surface and fall free in the air, a safe landing can be realized.

  According to the first aspect of the present invention, there is provided means for independently driving a plurality of wheels and a casing for connecting the plurality of wheels, and the casing is provided with means for detecting movement of the center of gravity of the passenger. A traveling device that sets the number of rotations of each of the wheels according to the detected information on the movement of the center of gravity, and includes a detection means for detecting acceleration in the gravitational direction on the casing, and the acceleration in the gravitational direction. It is possible to realize a safe landing even when the wheels are free-falling in the air away from the road surface by having a control means for detecting a change in the number of wheels and applying predetermined control to the rotational speeds of the plurality of wheels. is there.

  According to the invention of claim 2, the plurality of wheels are composed of two wheels whose rotation axes are arranged in a straight line, and the control by the control means keeps the casing horizontal for setting the number of rotations of the plurality of wheels. By including the elements, stable running can be performed.

  According to the invention of claim 3, when the fall of the housing is detected by detecting the acceleration in the direction of gravity, the control means performs a control that does not give a rotational torque to the plurality of wheels, so that a safe landing can be achieved. It can be realized.

  According to the invention of claim 4, the gyro sensor for detecting the angular velocity of the pitch axis is provided in the housing, and when the fall of the housing is detected by detecting the acceleration in the direction of gravity, the control means outputs the gyro sensor. By applying a predetermined torque control to the number of rotations of the wheels so that the housing has a desired angle, the wheels rotate backward with the same torque from the time when the housing angle becomes half of the target value. By performing the control, the casing can be kept horizontal.

  According to the fifth aspect of the present invention, the casing is further provided with detecting means for detecting the longitudinal acceleration and detecting means for detecting the rotational angular velocities of the plurality of wheels, and the control means controls the output of the gyro sensor and the longitudinal acceleration. By performing control to make the relative speed between the rotation of the wheel and the road surface zero using the integrated value and the detected value of the rotational angular velocity of the plurality of wheels, good running can be performed at the time of landing.

  According to the sixth aspect of the present invention, the plurality of wheels are independently driven, and the housing has a housing for connecting the plurality of wheels, and the housing is provided with means for detecting movement of the center of gravity of the passenger. A method of controlling a traveling device that performs traveling by setting the number of rotations of a plurality of wheels according to detected movement information of the center of gravity, and detects acceleration in the gravitational direction on a casing, and changes in acceleration in the gravitational direction By detecting the above and applying predetermined control to the rotational speeds of the plurality of wheels, a safe landing can be realized even when the wheels are free-falling in the air away from the road surface.

  According to the invention of claim 7, the plurality of wheels are composed of two wheels whose rotation axes are arranged in a straight line, and for predetermined control, the casing is kept horizontal for setting the number of rotations of the plurality of wheels. By including the elements, stable running can be performed.

  According to the invention of claim 8, when the fall of the housing is detected by detecting the acceleration in the direction of gravity, a safe landing can be realized by performing a control that does not give a rotational torque to a plurality of wheels. It can be done.

  According to the ninth aspect of the present invention, when the angular velocity of the pitch axis of the casing is detected and the fall of the casing is detected by detecting the acceleration in the gravitational direction, the casing is desired by the detection output of the angular velocity of the pitch axis. In addition to applying a predetermined torque control to the rotational speeds of the plurality of wheels so that the angle becomes the angle, the control is performed to reversely rotate the plurality of wheels with the same torque from the time when the angle of the housing becomes half of the target value. By this, the casing can be kept horizontal.

  According to the invention of claim 10, the longitudinal acceleration is detected in the casing and the rotational angular velocities of the plurality of wheels are detected, the angular axis velocity detection output, the integrated value of the longitudinal acceleration, and the plurality of wheels are detected. By performing control to make the relative speed between the rotation of the wheel and the road surface zero using the detected value of the rotational angular velocity, it is possible to perform good running at the time of landing.

  As a result, in the conventional device, when the wheel travels on a road surface with a large step and the wheel freely falls in the air away from the road surface, the wheel rotates at a high speed by the control device, and when the wheel that rotates at high speed lands on the road surface, The present invention can easily solve such problems according to the present invention, which suddenly travels and the posture becomes unstable, and the rider may fall into a dangerous state without being able to maintain the posture. Is something that can be done.

  The present invention will be described below with reference to the drawings. FIG. 1 is a front view (A) and a side view (B) showing a configuration of an embodiment of a coaxial two-wheeled vehicle to which a traveling device and a control method thereof according to the present invention are applied. It is.

  In FIG. 1, for example, left and right wheels 101 and 102 are provided. These left and right wheels 101 and 102 are arranged by a table (housing) 103 so that the axles 104 and 105 are in a straight line. Further, on the table 103, left and right motors 106 and 107 are disposed close to the wheels 101 and 102, respectively, and the rotation shafts 108 and 109 of the left and right motors 106 and 107 are respectively transmitted portions (reduction gears) 110 and 111. The wheels 101 and 102 are driven to rotate by being connected to the axles 104 and 105 through the wheel.

  In addition, a sensor circuit 112 such as a gyro sensor or an acceleration sensor for detecting the posture of the passenger is mounted on the table 103. Then, the sensor signal detected by the sensor circuit 112 is supplied to the control device 113 to control the driving of the motors 106 and 107, and the attitude of the table 103 with respect to the roll axis and the pitch axis is controlled. Control of charging of regenerative energy to a secondary battery 115 (not shown) is performed by a charging circuit 114 (not shown) provided alongside the control device 113.

  Furthermore, the system configuration of the entire apparatus of one embodiment of the coaxial two-wheeled vehicle to which the traveling apparatus and the control method thereof according to the present invention are applied is the same as that shown in FIG. The specific operation of such an apparatus will be described below.

  That is, as shown in FIG. 2, when a two-wheeled vehicle controlled by a motor travels on a stepped floor, it naturally falls along a locus determined by the traveling speed. At this time, since the floor reaction force is lost, it becomes impossible to maintain the posture by motor control. Further, since there is no floor reaction force during the fall, if the table posture angle changes, the motor rotates at a high speed and becomes in a dangerous state.

  On the other hand, since the motor rotation direction and rotation speed vary depending on the table posture angle, the landing direction cannot be determined, and there is a problem that the passenger falls down and causes a disaster. The present invention proposes a method of safely controlling while avoiding such a dangerous state.

  By the way, in the conventional control, the two-wheeled vehicle is controlled by the control principle of the inverted pendulum. In such an inverted pendulum control, for example, when there is a large level difference on the floor as shown in FIG. 2, the occupant takes a posture of leaning forward (traveling direction) when it reaches the position immediately before falling (traveling position (2)). A force that moves forward in the drop direction at high speed acts on the wheel by the control calculation.

  For this reason, the motor lands in a state of high-speed rotation, and the aircraft moves forward at high speed when landing. Thus, if the vehicle moves forward at a high speed when landing, the passenger cannot maintain his / her posture and is exposed to the risk of falling down, resulting in a very dangerous situation. In order to solve these problems, the present invention uses attitude control by ZMP instead of control by an inverted pendulum.

  That is, the fall state is estimated by using the state signals of the aircraft (posture position, XYZ position / velocity / acceleration, pitch-roll-yaw angle / angular acceleration / angular acceleration). By controlling so that the wheel does not rotate at high speed sometimes, it is possible to land safely so as to suppress the traveling speed at the time of landing.

  In the case of the inverted pendulum control, when the body moves in the traveling direction, the tire rotation speed Ω (t) [rad / sec] rotates at a high speed to control the posture when the posture changes at a time when there is a step. For this reason, at the time of landing, the aircraft advances at a high traveling speed as indicated by an arrow due to the road surface reaction force, and the passenger enters a dangerous state.

  Here, when there is a step as shown in FIG. 3, the floor area becomes narrow at the step position of the floor. Then, the tire is deformed and changes in the Z-axis (traveling position (2)). Here, when the airframe further advances and proceeds in the falling direction, the tire is further deformed and the change in the Z-axis is increased. Thus, the Z-axis change is detected, the step is recognized, the fall state can be predicted in advance, and the wheel rotation speed can be controlled so as to land safely. That is, since the ZMP can be controlled to be on the floor reaction force from the traveling position (1) to the traveling position (2), the posture can be kept stable.

  In contrast, at the travel position (2), a Z-axis change occurs and is detected by the Z-axis acceleration sensor. Since the step position is specified in this way, at the traveling position (2), the table angle can be changed as shown in FIG. 3 to change the posture of the occupant's center of gravity so as to be in the direction to avoid falling. At this time, the ZMP changes in the direction indicated by the arrow of the travel position (2), and the speed at which the ZMP falls from the step is attenuated. Thus, the vehicle can be moved in a direction to avoid the state where the ZMP is changed to fall from the step.

On the other hand, if the speed in the traveling direction (+ X direction) is high, the vehicle will fall over the step due to the inertial force of the aircraft and the passenger. In such a case, similarly to the above, at the travel position (2), the table posture angle is changed to attenuate the travel speed. However, when the travel speed is high, the ZMP falls beyond the step. In the fall state, the Z-axis acceleration sensor signal output changes abruptly so that the fall state can be detected. When the fall acceleration [1 G] (9.8 m / sec ² ) is detected by this Z-axis acceleration sensor, the motor torque output is set to zero.

  Then, the tire is easily rotated by an external force. Thus, when landing with the motor torque set to zero, the tire is freely rotated by the reaction force of the contact road surface. For this reason, since the tire freely rotates from the floor reaction force and absorbs the kinetic energy at the time of landing, the rider attenuates the floor reaction force from the road surface.

  Further, the table posture angle changes depending on the posture of the occupant, but the posture immediately before dropping is maintained in the state of dropping due to the law of inertia. That is, since it is in a stable posture before dropping, it is dropped in the posture of that state. When landing in this state, when the tire touches the road surface, it freely rotates according to the road surface condition, so that the change in the X direction due to the floor reaction force is absorbed, and it becomes easy to keep the posture stable by the law of inertia. .

  However, the table posture angle becomes unstable immediately after landing because it is only an action for the passenger to keep his posture stable. For this reason, the motor needs to quickly recover control and stably control the table posture angle. The landing state is detected because the Z-axis change occurs and the Z-axis acceleration sensor signal changes so that the tire is deformed and restored as shown in FIG. Immediately after landing, the motor can stably maintain the posture by controlling the posture so that the table posture angle is controlled stably so that the ZMP is on the floor reaction force.

  In this way, the passenger can continue traveling while maintaining his / her posture even after landing after falling. At this time, it is assumed that the occupant prepares for landing by changing his appearance so as to maintain his posture regardless of the table angle during the fall. In addition, the control device can perform control according to the flowcharts of FIGS.

  That is, in FIG. 5, during traveling operation, whether or not there is a change in the Z-axis acceleration is determined in step [1], and when it is changed (Yes), the fall prevention control as shown in FIG. 6 is performed in step [2]. Is done. Further, in step [3], it is determined again whether or not there is a change in the Z-axis acceleration, and when it has changed (Yes), drop landing control as shown in FIG. 7 is performed in step [4].

  When the Z-axis acceleration does not change in step [1] (No), the travel control as shown in FIG. 34 is performed in step [5]. If the Z-axis acceleration has not changed in step [3] (No), the process returns to step [1]. Further, after the processing in steps [4] and [5] is performed, it is determined in step [6] whether or not the traveling has stopped. If not (No), the process returns to step [1]. When it is stopped, the process is terminated.

  In the above-described fall prevention control of FIG. 6, when this process is called, the posture angle θREF is tilted in the opposite direction to the direction in which the Z-axis acceleration changes in step [7], and the ZMP is changed to the direction as shown in FIG. Change. As a result, the center of gravity of the occupant's body also changes like ZMP, and the aircraft advances in the fall prevention direction. After processing, the original routine is restored. In this way, the fall prevention control in step [2] is performed.

  Further, in the falling landing control of FIG. 7, when this process is called, in step [8], the travel commands Pref1, 2 shown in FIG. 22 are set to zero, and at the same time, the motor torque Tm is set to zero. Further, in step [9], the Z-axis fall acceleration is determined. When the fall is in progress (Yes), the process returns to step [8]. When the fall is completed (No), the original routine is restored. In this way, the drop landing control in step [4] is performed.

  In the above-described apparatus, the load sensor for detecting ZMP is configured as shown in FIG. 8, for example. In this configuration, the coordinates of the center of gravity (Xg, Yg) are obtained by the following equation.

W = PS1 + PS2 + PS3 + PS4-W0 [N]: W0 is its own weight without load W1 = (PS1 + PS4) / 2−W10 [N]: W10 is its own weight without load W2 = (PS2 + PS3) / 2−W20 [N]: W20 Is unloaded self weight W3 = (PS1 + PS2) / 2−W30 [N]: W30 is unloaded self weight W4 = (PS3 + PS4) / 2 W40 [N]: W40 is unloaded self weight Xg = L0 * ( W1-W2) / (W1 + W2) [m]
Yg = L1 * (W3-W4) / (W3 + W4) [m]

Here, when W is greater than or equal to a certain weight, the forward / backward movement is performed according to the sign and size of the value Xg. The tire command at time t at that time is given by the following equation.
Prefx (t) = Xg × Gx × t [rad] (Gx is a positive constant)
Pref1 (t) = Pref2 (t) = Prefx (t) [rad]

On the other hand, the pressure sensor signal is changed by the load load torque Tl as a load torque correction command, and the load load torque Tl is measured by the above equation. From this measured value, a torque that cancels Tl is calculated by the following equation. This calculated signal is defined as a load / load torque estimated value T′l.
T′l = W × Xg / 2 [Nm]
This calculation is executed by the regulator of FIG.

Further, an outline of the turning command will be described. That is, when turning using the output of the pressure sensor, PM is the barycentric coordinate signal Yg in FIG.
PM = Yg

Here, if the position commands of the left and right wheels at time t are Rref1 (t) and Rref2 (t) [rad], if the traveling speed Prefx (t) / dt is zero, the phase command is reversed and the right wheel and the left wheel The command is as follows.
Rref1 (t) = PM × G0 × t [rad]: Right wheel command (G0 is a positive constant value)
Rref2 (t) = − PM × G0 × t [rad]: Left wheel command

Therefore, when the traveling speed Prefx (t) / dt is not zero, the command is the same phase, and the commands for the right wheel and the left wheel are as follows.
Rref1 (t) = Prefx (t) + PM × G1 × t [rad]: Right wheel command (G1 is a positive constant value)
Rref2 (t) = Prefx (t) −PM × G1 × t [rad]: Left wheel command At this time, it is assumed that Rref1 (t) and Rref2 (t) have the same sign as Prefx (t). If the signs are different, the values of Rref1 (t) and Rref2 (t) are set to zero.

  With these Rref1 (t) and Rref2 (t), the left and right tires rotate at the rotational speeds Ω1 and Ω2 [rad / sec] in the circuit shown in FIG. The turning radius R and the turning speed ωyaw are determined by the difference between Ω1 and Ω2. Further, the upper limit of the turning speed ωyaw is defined by the turning speed defined in FIG. 35, so that the passenger can keep a stable posture and turn.

  Further, in the above-described embodiment, the bounce control method when the step is dropped is described below. That is, the gravitational acceleration sensor signal or the load sensor signal mounted on the table is zero because the floor reaction force disappears when dropped. When these signals are zero, that is, in the air, the posture can be controlled by applying motor torque to the tire inertia and the table inertia.

  Therefore, for example, during the travel positions (2) to (3) in FIG. 9, the posture can be controlled by the motor torque as shown in FIG. However, when the fall time is uncertain, the control of the moment of inertia force using the inertia in the air needs to be controlled by the time until contact with the road surface, so the control time is limited.

  On the other hand, in the present invention, the motor current is set to zero and the wheel rotation is rotated by a force (a floor reaction force or a ground friction force) acting on the tire from the outside, so that the floor reaction force at the time of landing is changed by the tire. The posture of the table is held by the inertial force of the table by absorbing the rotational force, and the posture control is performed when the posture can be controlled by detecting the stable state after the bounce using the acceleration sensor signal or the load sensor signal. Control is performed so as to be stable (see FIG. 9). In this way, the tire bounce problem can be avoided and the posture can be controlled.

  Furthermore, after falling from the step and bounce, the signals of the acceleration sensor and the load sensor on the fuselage change as shown in FIG. That is, when in the fall state or the bounce state, the motor current is zero and the motor is rotated by an external force. For this reason, the posture of the table is maintained by the inertial force. The state in which the vehicle is stably grounded on the road surface after the fall is determined from the values set by the load sensor and the acceleration sensor (see FIG. 9). After detecting the grounded state in this way, the occupant can stably maintain the posture by the posture control.

  In the above-described embodiment, a method for attitude control in free fall is as follows. That is, for example, when the motor torque τm [Nm] is applied at the time of free fall by the mechanism shown in FIG. 11, the table rotation speed and the tire rotation speed change according to FIG. Thus, the table rotation angle at the time of dropping can be controlled by generating the motor torque.

  On the other hand, when a step signal is given as the motor torque as shown in FIGS. 11 and 12, the table rotates by inversely proportional to the moment of inertia of the table. The rotation angle at that time is detected by the gyro sensor and the half of the target table angle is detected. If the time t0 [SEC] when the value is reached is given, the motor torque after t0 [SEC] will be the same magnitude in the reverse direction, and -τm [Nm] will give the target table angle after 2 x t0 seconds (See FIG. 13).

  Thus, when a motor torque that gives angular acceleration during free fall is generated, the table is rotated using the moment of inertia of the tire and the table to control the table to be stable at the time of landing, in this case the horizontal position. be able to. In addition, by controlling the motor current in this way, when there is no floor reaction force when falling, it is possible to generate angular acceleration torque so as to keep the table tilt angle horizontal, rotate the table, and keep the table horizontal (See FIG. 11).

  Furthermore, the method of attitude control in free fall will be described below. That is, FIG. 11 explains the relationship between the rotation speed and rotation angle of the tire and table during free fall. That is, even if the vehicle falls freely, the target angular velocity and angle of the tire and the table can be controlled by the motor torque. Here, the case where the tire rotation speed is set to zero relative speed with respect to the road surface during free fall is shown. It is also applicable to dropping on both wheels or one wheel.

Therefore, the free fall state is detected from the acceleration sensor Z-axis signal Gz mounted on the table by the mechanism of FIG. When the fall state is determined from the condition of the formula [Gz <1 [G]] from the acceleration sensor,
When Gz <1 [G] REF = Kv × ΔVEL
When Gz <1 [G] is not satisfied REF = θref
15 becomes a tire speed controller output by the command changer shown in FIG. 15, and simultaneously the pitch axis gyro sensor signal ωb [rad / sec], the rotor rotational angular velocity detector signal ωr [rad / sec] and the acceleration sensor shown in FIG. Add the integrated value Vx [rad / sec] of the X-axis signal Ax [m / sec ² ] and set the relative speed ΔVEL between the road surface and the tire [ΔVEL = ωb [rad / sec] + ωr [rad / sec] + Vx [rad / sec]].

  For the road surface-tire relative speed signal ΔVEL thus obtained, the tire speed controller (proportional controller or PD controller) calculates [Vx [rad / sec] = R × ∫Ax dt, R = tire radius]. Then, by giving the calculated value as the command value REF of the attitude controller [REF = Kv × ΔVEL], the relative speed between the tire and the road surface can be made zero.

  That is, by controlling the motor using the above-mentioned calculation place and landing, the contact frictional force resulting from the relative speed difference between the road surface and the tire can be reduced, and after landing, the command switcher of FIG. 15 is changed from [REF = Kv × ΔVEL]. Even when switching to the attitude command θref, it is possible to shift to attitude control in which the table angle becomes horizontal without generating a rotational moment force caused by a road surface frictional force.

  Thus, according to the above-described embodiment, the motor torque is controlled at the time of free fall to rotate the tire, the relative speed between the road surface and the tire can be made zero at the time of landing, the contact friction force can be reduced, Since the rotational moment force generated by the contact friction force can be reduced, the table posture can be kept stable. FIG. 15 is a control diagram of the right tire, but the left tire is described in the same manner. FIG. 15 shows a circuit added in the control system block internal configuration diagram of FIG. 40 described above.

Thus, according to the above-described embodiment,
1. Because the center of gravity is below the wheel axis, the aircraft will stop due to tire friction even if the control device malfunctions and will not operate, and the aircraft will keep the center of gravity in the most stable position. Can be kept horizontal due to the friction of the tires, making it difficult to tip over and prevent serious accidents. (See Figure 16)
2. When generating motor torque for rotating the wheels by the motor, the aircraft can move the aircraft while maintaining a stable posture with the center of gravity.
3. When generating motor torque for rotating the wheels by the motor, the aircraft can be moved while maintaining the level.
4). Since the load can be detected, it is possible to maintain a stable and constant performance against the fluctuation of the load. (See Figure 16)
5). It is possible to travel stably without a human being boarded by the pressure sensor.
6). Even if there is no handle by the pressure sensor, the human body moves the center of gravity position and determines the travel direction and travel speed based on the center of gravity position. Can do.
7). By performing feedback control of the yaw axis gyro sensor, it is possible to travel in a straight line by varying the rotational speed of the left and right wheels even if there is a difference in tire radius due to a difference in air pressure between the two wheels.
Further, even if there is a road surface difference between the left and right wheels, it is possible to travel in a straight line by changing the rotational speed of the left and right wheels.
8). A flexible tire increases the contact area of the road surface and increases rolling frictional resistance. For this reason, it is possible to stand stably even if a person rides.

  Furthermore, in the above-described embodiment, a tire structure as shown in FIG. 17 can be adopted. The tire structure shown in FIG. 17 is a rugged tire in which the convex portions are alternately shifted on the left and right sides with a flexible rubber material (natural rubber, chloroprene rubber) having vibration proof properties. Moreover, the center part of a tire becomes a groove | channel, and the unevenness | corrugation of a road surface is absorbed by the projection part of a vibration-proof rubber, and a vibration is prevented. The central part is a groove, and the area of the unevenness is the same area ratio.

  Furthermore, the tire and the ground contact portion of the road surface are tires in which the convex portion is deformed due to the weight of the fuselage to increase the contact area and the rolling friction resistance is increased, and the tires are CW (clockwise) and CCW (counterclockwise). ), Even if there is unevenness on the surface due to the phase difference on the left and right sides, it has uniform road resistance, and the aircraft can easily control the attitude of the aircraft by controlling the inverted pendulum or ZMP (zero moment point) control become able to. In addition, since the groove area and the protrusion area of the tire are the same, the protrusion is deformed at a portion that is in contact with the road surface, and the entire road surface is contacted to increase rolling friction.

  Therefore, according to such a tire structure, a large rolling friction can be obtained, so that a stable posture can be maintained. In addition, such a structure allows the X-axis to have low rigidity and high Y-axis rigidity, so that the Y-axis vibration and roll axis swing of the machine can be reduced.

  Thus, according to the traveling device described above, the vehicle has means for independently driving a plurality of wheels and a housing for connecting the plurality of wheels, and the housing is provided with means for detecting movement of the center of gravity of the passenger. A traveling device that sets the number of rotations of each of the wheels according to the detected information on the movement of the center of gravity, and includes a detection means for detecting acceleration in the gravitational direction on the casing, and the acceleration in the gravitational direction. It is possible to realize a safe landing even when the wheels are free-falling in the air away from the road surface by having a control means for detecting a change in the number of wheels and applying predetermined control to the rotational speeds of the plurality of wheels. is there.

  Further, according to the above-described control method of the traveling device, the plurality of wheels are independently driven, and the housing includes a housing that connects the plurality of wheels, and the housing includes means for detecting movement of the center of gravity of the occupant. A traveling device control method is provided for traveling by setting the rotational speeds of a plurality of wheels according to detected movement information of the center of gravity, and detecting acceleration in the gravitational direction on a casing, By detecting a change in acceleration and applying predetermined control to the number of rotations of multiple wheels, it is possible to achieve safe landing even when the wheels fall free from the road surface in the air. is there.

  The present invention is a vehicle that travels autonomously with the center of gravity below the wheel axis, and the posture control device that feeds back the posture sensor signal changes the weight center of gravity by a person riding on a vehicle that stably stabilizes the fuselage. It is a device that moves forward, reverse, or turns a vehicle, or a biped autonomous robot device, and is also applicable to a moving vehicle or robot that does not have a brake or accelerator mechanism. Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is the front view (A) and side view (B) which show the structure of one Embodiment of the coaxial two-wheeled vehicle to which the traveling apparatus by this invention and its control method are applied. It is explanatory drawing of the change of the driving | running | working state of the road surface with a level | step difference by control of an inverted pendulum. It is explanatory drawing of the traveling control in the floor with a level | step difference by control of ZMP. It is explanatory drawing of attitude | position control when falling. It is a flowchart figure of driving | running | working driving | operation. It is a flowchart figure of fall prevention. It is a flowchart figure of falling landing. It is a layout of the pressure sensor of the table. It is explanatory drawing of the motion change of the bounce state at the time of level | step fall, and a control state. It is explanatory drawing of the change of the sensor signal of the bounce state at the time of level | step difference falling. It is the front view (A) and side view (B) which show the structure of a tire and a table. It is a block diagram of motor torque-angular velocity and angle. It is explanatory drawing of a torque, table angular velocity, and an angle change. It is the front view (A) and side view (B) which show the structure of a tire and a table. It is a road surface-tire relative speed control figure. It is a figure which shows the relationship between a gravity center position, turning speed, and a load position. 1 is a structural diagram of a tire. It is an external appearance perspective view which shows embodiment of the coaxial two-wheeled vehicle which this inventor proposed previously. It is a sectional side view for demonstrating the base of a coaxial two-wheeled vehicle. It is a figure which shows the pressure sensor provided in the base of the coaxial two-wheeled vehicle, The figure (A) shows a top view, The figure (B) shows a side view. It is a figure which shows the positional relationship of the weight center of a coaxial two-wheeled vehicle, and a wheel shaft. It is a figure explaining balance of load load torque and motor torque. It is a figure explaining posture control in case a human boarded. It is a figure explaining the dynamic model for maintaining an attitude | position on a base. It is a figure explaining the dynamic model for maintaining an attitude | position on a base. It is a figure explaining the dynamic model for maintaining an attitude | position on a base. It is a figure explaining the dynamic model in a coaxial two-wheeled vehicle. It is a figure which shows the control mechanism for attitude | position stability control. It is a figure which shows the control mechanism for attitude | position stability control and driving | running | working control in case there is one wheel. It is a figure explaining the attitude | position command in a coaxial two-wheeled vehicle. It is a block diagram which shows the control mechanism for attitude | position stability control and driving | running | working control in case there is one wheel. It is a figure which shows the block diagram shown in FIG. 31 as a mathematical model. It is a figure which shows the detailed specific example of the mathematical model shown in FIG. It is a block diagram which shows the control mechanism for attitude | position stability control and driving | running | working control in case there are two wheels. It is a figure explaining traveling speed control in the case of going forward and retreating. It is a figure explaining traveling speed control in the case of turning. It is a figure explaining the control method in case the gyro sensor signal around a yaw axis is detected when going straight. It is a figure explaining the software structure of a coaxial two-wheeled vehicle. 1 is a diagram illustrating an overall configuration of each circuit in a coaxial two-wheel vehicle 1. FIG. It is a figure explaining the detailed internal structure of the whole structure shown in FIG. It is a figure explaining traveling speed control in the case of going forward and retreating.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101,102 ... Wheel, 103 ... Table, 104, 105 ... Axle, 106, 107 ... Motor, 108, 109 ... Rotating shaft, 110, 111 ... Transmission part, 112 ... Sensor circuit, 113 ... Control device

Claims (10)

Means for independently driving a plurality of wheels; and a housing for connecting the plurality of wheels, wherein the housing is provided with means for detecting movement of the center of gravity of the occupant, and the detected center of gravity. A traveling device configured to travel by setting the rotational speeds of the plurality of wheels according to the movement information of
A detection means for detecting acceleration in the gravitational direction is provided in the housing,
A traveling device comprising: a control unit that detects a change in acceleration in the direction of gravity and applies predetermined control to the rotational speeds of the plurality of wheels. The plurality of wheels are composed of two wheels whose rotational axes are arranged in a straight line,
The travel device according to claim 1, wherein the control by the control means includes an element for keeping the casing horizontal in setting the rotation speeds of the plurality of wheels. When the fall of the housing is detected by detecting the acceleration in the gravitational direction,
The traveling device according to claim 1, wherein the control unit performs control so as not to apply rotational torque to the plurality of wheels. A gyro sensor for detecting the angular velocity of the pitch axis is provided in the housing,
When the fall of the housing is detected by detecting the acceleration in the gravitational direction,
The control means applies a predetermined torque control to the rotation speeds of the plurality of wheels so that the casing has a desired angle based on the output of the gyro sensor, and the angle of the casing is half of the target value. The traveling device according to claim 1, wherein the control is performed to reversely rotate the plurality of wheels with an equal torque from the point of time. The housing further includes detection means for detecting acceleration in the front-rear direction and detection means for rotational angular velocities of the plurality of wheels,
The control means performs control for setting the relative speed between the rotation of the wheel and the road surface to zero using the output value of the gyro sensor, the integral value of the acceleration in the longitudinal direction, and the detected value of the rotational angular velocity of the plurality of wheels. The travel device according to claim 4, wherein the travel device is performed. A plurality of wheels are independently driven, and a housing for connecting the plurality of wheels is provided, and the housing is provided with means for detecting movement of the center of gravity of the occupant, and the movement of the detected center of gravity is provided. A traveling device control method for traveling by setting the rotational speeds of the plurality of wheels according to the information of
Detect acceleration in the direction of gravity in the housing,
A method for controlling a traveling device, comprising: detecting a change in acceleration in the direction of gravity and applying predetermined control to the rotational speeds of the plurality of wheels. The plurality of wheels are composed of two wheels whose rotational axes are arranged in a straight line,
The method for controlling the traveling device according to claim 6, wherein the predetermined control includes an element for keeping the casing horizontal in setting the rotation speeds of the plurality of wheels. When the fall of the housing is detected by detecting the acceleration in the gravitational direction,
The method for controlling the traveling device according to claim 7, wherein the control is performed so as not to apply a rotational torque to the plurality of wheels. Detecting the angular velocity of the pitch axis of the housing;
When the fall of the housing is detected by detecting the acceleration in the gravitational direction,
A predetermined torque control is applied to the rotational speeds of the plurality of wheels so that the casing has a desired angle based on the angular velocity detection output of the pitch axis, and
The method for controlling the traveling device according to claim 6, wherein control is performed to reversely rotate the plurality of wheels with an equal torque from a time point when the angle of the housing becomes half of the target value. Detecting acceleration in the front-rear direction on the housing and detecting rotational angular velocities of the plurality of wheels;
Performing control to set the relative speed between the rotation of the wheel and the road surface to zero using the detected output of the angular velocity of the pitch axis, the integrated value of the acceleration in the longitudinal direction, and the detected value of the rotational angular velocity of the plurality of wheels. The method for controlling a traveling device according to claim 9.

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