Saturation avoidance control device, attitude control device, self-propelled movement device and saturation avoidance control method

Abstract

To enable a CMG to continuously maintain high-accuracy attitude control for a long time.SOLUTION: A saturation avoidance control device 6, which executes saturation avoidance control for avoiding control saturation of a control moment gyro (CMG) during attitude control of an object 1 whose attitude is controlled, comprises a torque control part that controls a torque generating device 10 that generates saturation avoidance torque τs that is coaxial with attitude control torque τg that is generated by the control moment gyro during the attitude control, without using gyro effect. The torque control part controls the saturation avoidance torque so that attitude variation of the object whose attitude is controlled by the saturation avoidance torque makes an inclination angle θg of a wheel shaft 21a of the control moment gyro gets close to an initial angle during the attitude control.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a saturation avoidance control device, an attitude control device, a self-propelled mobile device, and a saturation avoidance control method that execute saturation avoidance control for avoiding control saturation of a control moment gyro (hereinafter also referred to as "CMG") during attitude control of an attitude control target.

Background Art

[0002] Generally, a CMG generates an attitude control torque due to the gyro effect by changing the inclination angle of the wheel axis (relative angle with respect to the initial angle) by rotating the rotation axis of the rotating wheel (wheel axis) around the rotation axis of the gimbal (gimbal axis). In a CMG, the attitude of the attitude control target is changed using the attitude control torque generated by controlling the gimbal to change the inclination angle of the wheel axis, and control is performed so that the attitude of the attitude control target becomes the target attitude. As such an attitude control device using a CMG, for example, those disclosed in Patent Document 1 are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the Control Moment Gyro (CMG) can achieve high-precision attitude control, its utilization is being considered for many attitude control targets that require high-precision attitude control. However, the CMG has a limit in the control range of the inclination angle of the wheel axis for attitude control and cannot continuously generate a saturation avoidance torque in a certain direction. Therefore, when the inclination angle of the wheel axis reaches the limit angle due to attitude control by the CMG, the CMG enters a control saturation state where further attitude control cannot be performed. Thus, conventional attitude control devices have had the problem that high-precision attitude control by the CMG cannot be continuously maintained for a long period of time.

Means for Solving the Problem

[0005] One aspect of the present invention is a saturation avoidance control device that executes saturation avoidance control for avoiding control saturation of a control moment gyro during attitude control of an attitude control target, the saturation avoidance control device having a torque control unit that controls a torque generation device that generates a saturation avoidance torque coaxial with the attitude control torque generated by the control moment gyro during attitude control without using the gyro effect, and the torque control unit controls the saturation avoidance torque such that the attitude change of the attitude control target due to the saturation avoidance torque approaches the initial angle of the inclination angle of the wheel axis of the control moment gyro during attitude control. As a method for avoiding control saturation of the Control Moment Gyro (CMG), for example, a method of returning the inclination angle of the wheel axis of the CMG that has reached the limit angle to the initial angle by the gimbal of the CMG can be considered. However, in this method, since it is necessary to interrupt the attitude control by the CMG while returning the inclination angle of the wheel axis to the initial angle, there is a period during which attitude control cannot be performed, and continuous attitude control cannot be maintained. Also, if the inclination angle of the wheel axis is rapidly returned to the initial angle while the wheel of the CMG is in a rotating state, it becomes difficult to control the attitude control target due to the reaction force. In addition, a method of continuously maintaining attitude control can be considered by controlling the attitude of one attitude control target using a plurality of CMGs. Even if one CMG reaches a control saturation state, attitude control by other CMGs can be continued. However, in this method, if all CMGs reach the control saturation state, attitude control cannot be performed, so there may be a case where continuous attitude control cannot be maintained. In this aspect, a torque generating device that generates a saturation avoidance torque coaxial with the attitude control torque generated by the CMG is used, and the saturation avoidance torque that brings the inclination angle of the wheel axis of the CMG during attitude control closer to the initial angle is generated by the torque generating device. By this saturation avoidance torque, it is possible to avoid a situation (control saturation state) in which the inclination angle of the wheel axis of the CMG reaches the limit angle during attitude control. And in this aspect, as the torque generating device that generates the saturation avoidance torque, one that generates the saturation avoidance torque without using the gyroscopic effect is adopted. Thereby, compared with a torque generating device that cannot continuously generate a saturation avoidance torque in a fixed direction like the CMG, it is possible to continue the avoidance control (saturation avoidance control) of the control saturation state of the CMG by the saturation avoidance torque for a longer period. Therefore, according to this aspect, it is possible to continuously maintain high-precision attitude control by the CMG for a longer period.

[0006] In the saturation avoidance control device, the torque generating device may have a non-saturated configuration capable of continuously generating the saturation avoidance torque. According to this, since it is possible to continue the avoidance control (saturation avoidance control) of the control saturation state of the CMG by the saturation avoidance torque, continuous attitude control can be stably maintained.

[0007] In the saturation avoidance control device, the attitude control by the control moment gyro may control the rotational position of the attitude control target about the axis of a predetermined elongated member, and the torque generator may include a drive rotating body that abuts against the circumferential surface of the elongated member and rotationally drives the attitude control target about the axis of the elongated member, and an axis angle changing unit that changes the angle of the rotation axis of the drive rotating body with respect to the axis of the elongated member. The torque control unit may perform control of the saturation avoidance torque by controlling the axis angle changing unit to change the angle of the rotation axis of the drive rotating body. This aspect is also applicable to the saturation avoidance control of the CMG when the rotational position (attitude) of the attitude control target about the axis of a predetermined elongated member is controlled by the CMG. However, in this aspect, as the torque generator, a drive rotating body that abuts against the circumferential surface of the elongated member and rotationally drives the attitude control target about the axis of the elongated member, and an axis angle changing unit that changes the angle of the rotation axis of the drive rotating body with respect to the axis of the elongated member are used. Then, by using this torque generator and performing control to change the angle of the rotation axis of the drive rotating body by the axis angle changing unit, it is possible to continuously generate a desired saturation avoidance torque about the axis of the elongated member. According to this, since it is possible to continuously generate a saturation avoidance torque for avoiding the control saturation state of the CMG, it is possible to stably and continuously control the rotational position (attitude) of the attitude control target about the axis of the elongated member. In particular, in this aspect, while the drive rotating body is rotationally driven in a certain direction, by changing the angle of the rotation axis of the drive rotating body by the axis angle changing unit, it is possible to generate both a clockwise saturation avoidance torque and a counterclockwise saturation avoidance torque about the axis of the elongated member. Therefore, the control for switching the rotation direction of the drive rotating body forward and backward becomes unnecessary, and it is possible to more smoothly avoid the control saturation state of the CMG due to the saturation avoidance torque.

[0008] In the saturation avoidance control device, the attitude control by the control moment gyro may control the rotational position of the attitude control target about the axis of a predetermined elongated member, the torque generator may include a drive rotating body that contacts the circumferential surface of the elongated member and rotationally drives the attitude control target about the axis of the elongated member, and the torque control unit may control the saturation avoidance torque by controlling the drive of the drive rotating body. This aspect is applicable to the saturation avoidance control of the CMG when controlling the rotational position (attitude) of the attitude control target about the axis of a predetermined elongated member by the CMG. In this aspect, as the torque generator that generates the saturation avoidance torque, one including a drive rotating body that contacts the circumferential surface of the elongated member and rotationally drives the attitude control target about the axis of the elongated member is used. By using this torque generator and performing drive control of the drive rotating body (for example, control of the rotational speed and rotational direction of the drive rotating body), it is possible to continuously generate a desired saturation avoidance torque about the axis of the elongated member. According to this, since it becomes possible to continuously generate a saturation avoidance torque for avoiding the control saturation state of the CMG, it is possible to stably and continuously control the rotational position (attitude) of the attitude control target about the axis of the elongated member.

[0009] In the saturation avoidance control device, the torque control unit may continuously control the saturation avoidance torque at predetermined time intervals. According to this, as a result of the control of the saturation avoidance torque being continuously performed at predetermined time intervals, it becomes possible to perform attitude control while changing the inclination angle of the wheel axis of the CMG near the initial angle. When performing attitude control by the CMG near the initial angle, it is possible to perform attitude control with a larger attitude control torque than when performing attitude control by the CMG at an angle away from the initial angle, so the attitude of the attitude control target can be changed more quickly, and more accurate attitude control becomes possible.

[0010] In the saturation avoidance control device, when the inclination angle of the wheel axis of the control moment gyro during attitude control deviates from the initial angle by a predetermined angle or more, the torque control unit may perform control of the saturation avoidance torque, and when it is within a range less than the predetermined angle from the initial angle, the control of the saturation avoidance torque may not be performed. When performing attitude control of an attitude control target with an attitude control torque by a CMG, it can be said that the saturation avoidance torque for avoiding control saturation of the CMG is a disturbance torque that inhibits the attitude control by the attitude control torque. In this aspect, when the inclination angle of the wheel axis of the CMG during attitude control is within a range less than a predetermined angle from the initial angle, control of the saturation avoidance torque for bringing the inclination angle of the wheel axis of the CMG during attitude control closer to the initial angle is not performed. According to this, while the inclination angle of the wheel axis is within the above range, attitude control of the attitude control target can be performed by the attitude control torque of the CMG without being affected by the disturbance of the saturation avoidance torque, and more accurate attitude control can be realized. On the other hand, when the inclination angle of the wheel axis of the CMG during attitude control deviates from the initial angle by a predetermined angle or more, control of the saturation avoidance torque is performed, and the inclination angle of the wheel axis of the CMG during attitude control is corrected to approach the initial angle. As a result, it is possible to avoid the CMG from entering a control saturation state. From the above, according to this aspect, it is possible to realize highly accurate attitude control by the CMG while avoiding the CMG from entering a control saturation state.

[0011] In the saturation avoidance control device, the torque control unit may obtain a control target value of the control moment gyro during attitude control and perform control of the saturation avoidance torque using the control target value. When performing control of the saturation avoidance torque so as to bring the inclination angle of the wheel axis of the CMG during attitude control closer to the initial angle, it is conceivable to feedback the detection result of the inclination angle of the wheel axis to the torque control unit to perform feedback control of the saturation avoidance torque. In this feedback control, a certain time lag occurs. If the sampling period of the feedback control is sufficiently short, the response delay will not be a problem. However, if the sampling period is insufficiently short, it may be difficult to quickly bring the inclination angle of the wheel axis closer to the initial angle. In this aspect, since the control of the saturation avoidance torque is performed using the control target value of the CMG during attitude control, feedforward control that predicts the inclination angle of the wheel axis of the CMG from the control target value becomes possible. Therefore, it is possible to quickly bring the inclination angle of the wheel axis closer to the initial angle. Note that this aspect does not exclude a control that combines feedback control and feedforward control.

[0012] Another aspect of the present invention is an attitude control device that performs attitude control of an attitude control target using a control moment gyro, including a torque generation device that generates a saturation avoidance torque coaxial with the attitude control torque generated by the control moment gyro during attitude control without using the gyro effect, and a saturation avoidance control device that executes saturation avoidance control for avoiding control saturation of the control moment gyro during attitude control of the attitude control target, and using the above-described saturation avoidance control device as the saturation avoidance control device. According to this aspect, it is possible to provide an attitude control device capable of continuously maintaining high-precision attitude control by the CMG for a long period of time.

[0013] Still another aspect of the present invention is a self-propelled mobile device that moves along an elongated path member by the rotational driving force of a driving rotating body that contacts the circumferential surface of the path member, the self-propelled mobile device comprising an axis angle changing unit that changes the angle of the rotation axis of the driving rotating body with respect to the axis of the path member, and using the above-described attitude control device as an attitude control device that performs attitude control for controlling the rotational position of the self-propelled mobile device around the axis of the path member, and using the above-described saturation avoidance control device as the saturation avoidance control device, the torque control unit performs control of the saturation avoidance torque by controlling the axis angle changing unit to change the angle of the rotation axis of the driving rotating body. According to this aspect, the attitude (rotational position of the self-propelled mobile device around the axis of the path member) of the self-propelled mobile device moving along the elongated path member can be continuously controlled by high-precision attitude control by the CMG over a long period of time.

[0014] In the self-propelled mobile device, the attitude control by the control moment gyro may be control such that the rotational position of the self-propelled mobile device follows a target rotational position that changes with time around the axis of the path member. According to this aspect, in the case where the self-propelled mobile device moves along the path member while rotating around the axis of the path member, the rotational position of the self-propelled mobile device around the axis of the path member can be continuously controlled by high-precision attitude control by the CMG over a long period of time.

[0015] Still another aspect of the present invention is a saturation avoidance control method for avoiding control saturation of a control moment gyro during attitude control of an attitude control target, the method comprising controlling a torque generating device that generates a saturation avoidance torque coaxial with the attitude control torque generated by the control moment gyro during attitude control without using the gyro effect, and performing control of the saturation avoidance torque such that the attitude change of the attitude control target by the saturation avoidance torque approaches the initial angle of the inclination angle of the wheel axis of the control moment gyro during attitude control. According to this aspect, it becomes possible to continuously maintain high-precision attitude control by CMG for a longer period of time.

Advantages of the Invention

[0016] According to the present invention, it becomes possible to continuously maintain high-precision attitude control by CMG for a long period of time.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiment for Carrying Out the Invention

[0018] Hereinafter, an embodiment in which a saturation avoidance control device according to the present invention is applied to an attitude control device of a self-propelled mobile device will be described. Note that the saturation avoidance control device according to the present invention is not limited to the attitude control device in the self-propelled mobile device of the present embodiment as long as it is an attitude control device that performs attitude control using a CMG, and can be widely applied to attitude control devices in spacecraft such as artificial satellites and other devices.

[0019] FIG. 1 is a perspective view showing a drive device 1 of a lifting device, which is a self-propelled mobile device of the present embodiment. The self-propelled mobile device of the present embodiment is a drive device of a lifting device that moves on a wire rope, which is an elongated path member. This drive device 1 uses a wire rope 100, which is a member having a substantially circular cross-section, as an elongated path member arranged along a predetermined lifting path, and can move along this wire rope 100 to perform lifting and lowering. In the present embodiment, an example in which the wire rope 100 is arranged along the vertical direction is shown, but it may be arranged obliquely with respect to the vertical direction, horizontally, or a combination of these.

[0020] This drive device 1 is assumed to be used in a case where the lifting distance is long. Therefore, the wire rope 100 is stretched with a strong tension. Examples of such cases include cases where cleaning, inspection, etc. of high-rise buildings, towers, etc. are performed using a lifting device, a stratosphere elevator that ascends and descends a lifting path extending from the ground to the stratosphere, a space elevator or an orbital elevator that ascends and descends a lifting path extending from the earth to above the geostationary orbit, and various other cases. Various components such as a cleaning member, an imaging device, and a cage (gauge) are attached to the lifting device main body according to the application of the lifting device on which this drive device 1 is mounted, but descriptions of these components are omitted.

[0021] The drive device 1 of this embodiment includes a main body frame 2, two rope holding mechanisms 3 and 4, a power supply unit 5, a control unit 6, a spiral propulsion mechanism 10, and a CMG mechanism 20.

[0022] FIG. 2 is a perspective view showing a state in which a part of the spiral propulsion mechanism 10 and the CMG mechanism 20 are removed from the drive device 1 of this embodiment. In the drive device 1 of this embodiment, a first rope holding mechanism 3 is supported on the upper part of the main body frame 2, and a second rope holding mechanism 4 is supported on the lower part of the main body frame 2.

[0023] The first rope holding mechanism 3 includes two pairs of driven rollers 3a and 3b that sandwich a wire rope 100 extending in the y-axis direction from the z-axis direction, and two anti-derailment plates 3c and 3c that sandwich the wire rope 100 from the x-axis direction to prevent derailment. Further, the second rope holding mechanism 4 includes a pair of driven rollers 4a that sandwich a wire rope 100 extending in the y-axis direction from the x-axis direction, and two support plates 4c and 4c that pivotally support the rollers of the pair of driven rollers 4a. By these rope holding mechanisms 3 and 4, the main body frame 2 is positioned and held so as not to shift with respect to the wire rope 100.

[0024] The second rope holding mechanism 4 is provided with an encoder as speed detection means for detecting the rotational speed of the pair of driven rollers 4a. The output of this encoder is sent to the control unit 6. The control unit 6 can detect the moving speed (ascending speed, descending speed) of the drive device 1 moving along the wire rope 100 from this encoder output.

[0025] An opening is provided in the central portion of the two anti-derailment plates 3c and 3c in the first rope holding mechanism 3. The drive rollers of the drive units 10A and 10B of the spiral propulsion mechanism 10 described later abut against the portion of the wire rope 100 exposed from these openings through the openings.

[0026] The power supply unit 5 supplies power to various power-consuming units (control unit 6, spiral propulsion mechanism 10, CMG mechanism 20, etc.) that consume power in the main drive device 1. In this embodiment, a battery as a power storage unit is provided. The power supply unit 5 is supported by the main body frame 2.

[0027] The control unit 6 controls each part of the main drive device 1 such as the spiral propulsion mechanism 10 and the CMG mechanism 20. The control unit 6 in this embodiment includes a 9-axis sensor (a 3-axis acceleration sensor, a 3-axis gyro sensor, and a 3-axis geomagnetic sensor) as an attitude detection means for detecting the attitude of the drive device 1, and uses the detection results of this sensor for various controls. Further, the control unit 6 receives an encoder output for detecting the rotational speed of the driven roller pair 4a of the second rope holding mechanism 4, detects the moving speed (ascending speed, descending speed) of the drive device 1 moving along the wire rope 100, and also uses the detection results for various controls.

[0028] The control unit 6 in this embodiment functions as a movement control unit (movement control system) that controls the spiral propulsion mechanism 10 to control the movement of the drive device 1 along the wire rope 100, an attitude control unit (attitude control system) that controls the CMG mechanism 20 to control the attitude of the drive device 1 (the rotational position of the drive device 1 around the axis of the wire rope 100, that is, the rotational angle around the y-axis), etc. In particular, the control unit 6 in this embodiment functions as a saturation avoidance control unit (saturation avoidance control system) for avoiding the control saturation of the CMG mechanism 20 during attitude control. The control unit 6 is supported by the main body frame 2.

[0029] Next, the spiral propulsion mechanism 10 of the main drive device 1 will be described. FIG. 3 is a perspective view showing the state where the CMG mechanism 20 is removed from the drive device 1 in this embodiment, and is a perspective view showing the spiral propulsion mechanism 10 of the main drive device 1. FIGS. 4(a) to (c) are perspective views showing the first drive unit 10A in the spiral propulsion mechanism 10 of the main drive device 1.

[0030] The spiral propulsion mechanism 10 of the present drive device 1 includes two drive units 10A and 10B, each of which includes a drive roller 11 as a drive rotating body. The two drive units 10A and 10B are supported by the main body frame 2 via their respective support frames 12 so as to face each other from the x-axis direction with the wire rope 100 extending in the y-axis direction interposed therebetween.

[0031] Since the configurations and operations of the two drive units 10A and 10B are substantially the same, the first drive unit 10A will be described as an example. The first drive unit 10A includes a drive roller 11 as a drive rotating body, a support frame 12, a roller frame 13, a drive motor 14 which is a drive source of the drive roller, and a posture changing motor 15 for the drive roller.

[0032] The drive roller 11 of the first drive unit 10A is arranged to contact the circumferential surface of the wire rope 100 from the x-axis direction and sandwich the wire rope 100 between the drive roller 11 of the second drive unit 10B. Both ends of the roller shaft of the drive roller 11 are rotatably supported with respect to the roller frame 13. The drive motor 14 that generates a rotational driving force for rotationally driving the drive roller 11 is supported on the roller frame 13. The driving force from the drive motor 14 is transmitted to the roller shaft of the drive roller 11 via a drive transmission mechanism such as a gear. Since the two drive motors 14 and 14 in the two drive units 10A and 10B are synchronized with each other, the two drive rollers 11 and 11 that sandwich the wire rope 100 rotate synchronously.

[0033] The roller frame 13 is pivotally supported with respect to the support frame 12 so as to be rotatable about the x-axis. The output shaft of the attitude change motor 15 supported by the support frame 12 is connected to the rotation axis of the roller frame 13. The attitude change motor 15 is a motor that can rotate forward and backward. By controlling the attitude change motor 15, the roller frame 13 can be rotated in either the forward or reverse direction about the x-axis. That is, by controlling the attitude change motor 15, the roller shaft of the drive roller 11 supported by the roller frame 13 can be rotated in either the forward or reverse direction about the x-axis.

[0034] The attitude of the drive roller 11 shown in FIG. 4(a) is an attitude in which the axial direction of the drive roller 11 and the axial direction of the wire rope 100 (y-axis direction) are orthogonal (hereinafter referred to as "orthogonal attitude"). Here, the roller angle θm is defined as the angle formed by the z-axis and the direction opposite to the surface movement direction of the circumferential surface of the drive roller 11 in contact with the wire rope 100 (the direction of the frictional force F generated on the circumferential surface of the drive roller 11 in contact with the circumferential surface of the wire rope 100 due to the rotational drive of the drive roller 11). In this case, in the orthogonal attitude, the roller angle θm is ±90°.

[0035] When the attitude change motor 15 is driven from the orthogonal attitude (θm = ±90°), the first drive units 10A each rotate about the output shaft (x-axis) of the attitude change motor 15. As a result, the attitude of the drive roller 11 becomes, for example, an inclined state (θm = +45°) in which the angle formed by the axial direction of the drive roller 11 and the axial direction of the wire rope 100 (y-axis) is about 45° (hereinafter referred to as "inclined attitude"), as shown in FIG. 4(b).

[0036] In the present embodiment, the attitude change motors 15, 15 of the two drive units 10A, 10B are synchronized with each other. Specifically, the attitude change motors 15, 15 are synchronized with each other such that the relationship between the axial direction of one drive roller 11 and the axial direction of the other drive roller 11 is line-symmetrical with respect to the wire rope 100 on the projection plane obtained by projecting these axial directions onto the vertical plane including the wire rope 100.

[0037] FIG. 5 is a schematic diagram for explaining the forces generated by the two drive rollers 11, 11 in the spiral propulsion mechanism 10. When the postures of the drive rollers 11, 11 in the two drive units 10A, 10B are the inclined postures shown in FIG. 4(b), as shown in FIG. 5, the circumferential surface of the drive roller 11 of the first drive unit 10A receives a frictional force F1 from the wire rope 100 during rotational drive, and the circumferential surface of the drive roller 11 of the second drive unit 10B receives a frictional force F2 from the wire rope 100 during rotational drive. Among these frictional forces F1, F2, the y-axis direction component forces Fy1, Fy2 act as moving forces for moving (lifting) the drive device 1 along the wire rope 100. On the other hand, among these frictional forces F1, F2, the y-axis rotational component forces Fr1, Fr2 act as a spiral torque τs for rotating the drive device 1 around the axis of the wire rope 100 (around the y-axis).

[0038] Also, when the posture change motor 15 is further driven from the inclined posture, as shown in FIG. 4(c), the posture in which the axial direction of the drive roller 11 and the axial direction of the wire rope 100 (y-axis direction) are parallel (hereinafter referred to as the "parallel posture") can be achieved. In this parallel posture, the roller angle θm becomes 0°. At this time, the frictional forces F1, F2 received by the circumferential surfaces of the drive rollers 11, 11 of the two drive units 10A, 10B from the wire rope 100 during rotational drive are only the components Fr1, Fr2 in the y-axis rotation direction, and the y-axis direction component forces Fy1, Fy2 do not occur. Therefore, in the parallel posture, a spiral torque τs for rotating the drive device 1 around the axis of the wire rope 100 (around the y-axis) can be generated without moving the drive device 1 along the wire rope 100.

[0039] Subsequently, an example of the movement control of the drive device 1 by the spiral propulsion mechanism 10 will be described. When the driving device 1 is raised or lowered along the wire rope 100, the control unit 6 controls the posture change motor 15 so that, as shown in Fig. 4(a), the roller shafts of the drive rollers 11, 11 of each drive unit 10A, 10B of the spiral propulsion mechanism 10 face in a direction (z-axis direction) orthogonal to the axial direction (y-axis direction) of the wire rope 100. When the drive motors 14, 14 are driven in this orthogonal posture state (θm = ±90°) and the drive rollers 11, 11 rotate around their respective roller shafts, the frictional forces Fj (= F1 + F2) between the wire rope 100 and the circumferential surfaces of the drive rollers 11, 11 coincide with the axial direction (y-axis direction) of the wire rope 100, and the driving device 1 moves (rises or falls) along the wire rope 100.

[0040] Even when the circumferential surfaces of the drive rollers 11, 11 move straight along the axis (y-axis) of the wire rope 100 (in the orthogonal posture state (θm = ±90°)), the driving device 1 may rotate around the axis of the wire rope 100 (y-axis rotation) under the influence of external forces such as wind or the twist of the wire rope 100. In this embodiment, in order to cancel the posture change of the driving device 1 due to such y-axis rotation, posture control is performed by the CMG mechanism 20.

[0041] Next, the CMG mechanism 20 of the present driving device 1 will be described. Fig. 6 is a perspective view showing the CMG mechanism 20 of this embodiment. The CMG mechanism 20 includes a flywheel 21 which is a wheel, a support frame 22, a wheel frame 23, a wheel drive motor 24, a gimbal 25, and an encoder 26. The encoder 26 is a detection means for detecting the rotational speed of the flywheel 21, and the detection result is sent to the control unit 6.

[0042] The flywheel 21 is a rotating body for generating attitude control torque by the gyroscopic effect. The wheel axis 21a, which is the rotation axis of the flywheel 21, is rotatably supported at both ends with respect to the wheel frame 23. The wheel drive motor 24 for generating a rotational driving force for rotationally driving the flywheel 21 is supported on the wheel frame 23. A driving force from the wheel drive motor 24 is transmitted to the wheel axis 21a of the flywheel 21 via a driving transmission mechanism such as a gear.

[0043] The wheel frame 23 is rotatably supported with respect to the support frame 22 about the z-axis. A gimbal 25 is connected to the rotation axis (gimbal axis) of the wheel frame 23. The gimbal 25 rotates the wheel axis 21a of the flywheel 21 about the z-axis to change the inclination angle with respect to the x-axis. The gimbal 25 includes a gimbal motor 25a capable of forward and reverse rotation, and the output shaft of the gimbal motor 25a is connected to the rotation axis (gimbal axis) of the wheel frame 23.

[0044] Thereby, by controlling the gimbal motor 25a, the wheel frame 23 can be rotated in either the forward or reverse direction about the z-axis. That is, by controlling the gimbal motor 25a of the gimbal 25, the inclination angle (inclination angle with respect to the x-axis) of the wheel axis 21a of the flywheel 21 supported by the wheel frame 23 can be controlled.

[0045] Subsequently, an example of the attitude control of the drive device 1 by the CMG mechanism 20 will be described. FIG. 7 is a schematic diagram for explaining the attitude control of the drive device 1 by the CMG mechanism 20. As shown in Fig. 7, the CMG mechanism 20 rotationally drives the flywheel 21 at a rotational speed of angular velocity ωw by the wheel drive motor 24. In this state, when a moment M about the z-axis is generated by the gimbal 25 to change the inclination angle (gyro angle) θg of the wheel axis 21a of the flywheel 21, a gyro torque τg about the y-axis is generated due to the gyro effect. The gyro torque τg at this time can be expressed by the following formula (1) when the moment of inertia of the flywheel 21 is Jw.

[0046] [Number]

[0047] In the following description, the inclination angle (gyro angle) θg of the wheel axis 21a is set to zero [°] when the axial direction of the wheel axis 21a coincides with the x-axis direction, positive (plus) when the axial direction of the wheel axis 21a faces upward in the vertical direction, and negative (minus) when the axial direction of the wheel axis 21a faces downward in the vertical direction.

[0048] The CMG mechanism 20 can generate a desired gyro torque τg about the y-axis by controlling the gimbal 25 to change the inclination angle θg of the wheel axis 21a of the flywheel 21. When the drive device 1 is about to rotate about the axis of the wire rope 100 (y-axis) under the influence of external forces such as wind or torsion of the wire rope 100, the CMG mechanism 20 generates a gyro torque τg that cancels this rotation of the drive device 1. Thereby, attitude control can be performed so that the drive device 1 does not rotate about the axis of the wire rope 100 (y-axis) (is maintained in the target attitude).

[0049] Here, the CMG mechanism 20 has a limit in the control range of the tilt angle (gyro angle) θg of the wheel axis 21a that can be attitude-controlled. Theoretically, when the tilt angle θg of the wheel axis 21a reaches the limit angle of ±90 [°], the gyro torque τg around the y-axis cannot be generated, and the control saturation state where attitude control cannot be performed is reached. Realistically, due to restrictions in the layout of components and members around the flywheel 21, the tilt angle θg of the wheel axis 21a can only be changed within a limited angle range, for example, ±45 [°]. In this case, the control saturation state is reached when the tilt angle θg of the wheel axis 21a reaches ±45 [°].

[0050] In a situation where a biased external force acts on the drive device 1, attitude control for canceling the attitude change of the drive device 1 in the rotational direction corresponding to the biased external force is accumulated, and the tilt angle θg of the wheel axis 21a reaches one of the limit angles, causing the CMG mechanism 20 to enter the control saturation state.

[0051] In particular, there may be a continuous attitude change of the drive device 1 that rotates in a certain direction around the axis of the wire rope 100 (around the y-axis). For example, when the drive device 1 moves along the wire rope 100 and the twist of the wire rope 100 accumulates, when the twist is released, an attitude change may occur in which the drive device 1 rotates in a certain direction around the axis of the wire rope 100 (around the y-axis). In order to cancel the attitude change of the drive device 1 that rotates in a certain direction around the y-axis, the CMG mechanism 20 performs attitude control to continuously change the tilt angle θg of the wheel axis 21a in a certain direction. As a result, the tilt angle θg of the wheel axis 21a reaches the limit angle at an early stage, and the CMG mechanism 20 enters the control saturation state.

[0052] Next, saturation avoidance control for avoiding the control saturation state of the CMG mechanism 20 during the attitude control of the drive device 1 will be described. In this embodiment, as described above, the spiral propulsion mechanism 10 can generate a spiral torque τs (Frj = Fr1 + Fr2) about the y-axis by setting the drive rollers 11, 11 of the two drive units 10A, 10B to an inclined posture (0[°] < θm < 180[°]) or a parallel posture (θm = 0[°]). That is, the spiral propulsion mechanism 10 can be used as a torque generating device that generates a saturation avoidance torque (spiral torque τs) about the same y-axis as the attitude control torque (gyro torque τg) generated by the CMG mechanism 20.

[0053] In this embodiment, saturation avoidance control is executed by controlling the saturation avoidance torque (spiral torque τs) generated by this spiral propulsion mechanism 10 to make the inclination angle (gyro angle) θg of the wheel axis 21a of the CMG mechanism 20 during attitude control approach the initial angle of 0[°]. By this saturation avoidance control, it is possible to avoid a situation (control saturation state) in which the inclination angle θg of the wheel axis 21a of the CMG mechanism 20 reaches the limit angle during attitude control.

[0054] Fig. 8 is a schematic diagram for explaining the saturation avoidance control in this embodiment. In the following description, let the moment of inertia about the y-axis of the drive device 1 be Jr, the viscous coefficient about the y-axis of the drive device 1 be Dr, the disturbance about the y-axis acting on the drive device 1 be Tr, the rotation angle about the y-axis of the drive device 1 be θc, and the angular velocity of rotation about the y-axis of the drive device 1 be ωc. At this time, the equation of motion about the y-axis in the drive device 1 in this embodiment can be expressed by the following formula (2).

[0055]

Equation

[0056] First, in the attitude control system of the control unit 6 that controls the CMG mechanism 20, the spiral torque τs generated by the spiral propulsion mechanism 10 can be considered as a disturbance d (= τs - Tr), similar to external forces such as wind and disturbances Tr such as the twist of the wire rope 100. Therefore, the equation of motion of the above formula (2) can be replaced as the following formula (3).

[0057]

Number

[0058] Therefore, in the attitude control system of the control unit 6, according to the equation of motion of the above formula (3), with the gyro torque τg as the input and the rotation angle θc of the drive device 1 around the y-axis as the control target of the output, the CMG mechanism 20 is controlled.

[0059] Specifically, the control unit 6 acquires the rotation angle θcr of the drive device 1 around the y-axis from the output result of the 9-axis sensor, and calculates the attitude control torque τg for making this rotation angle θcr the target rotation angle θct (= 0 [°]). Then, the control unit 6 controls the gimbal 25 of the CMG mechanism 20 so that the calculated attitude control torque τg is generated, and changes the inclination angle θg of the wheel shaft 21a of the flywheel 21 of the CMG mechanism 20. As a result, an angular velocity ωc is generated in the drive device 1 such that the rotation angle θc around the y-axis approaches the target rotation angle θct, which is 0 [°]. By repeating this control, attitude control is performed to maintain the attitude (rotation angle) of the drive device 1 around the y-axis at the desired attitude (rotation angle θc = 0 [°]).

[0060] Next, the saturation avoidance control system of the control unit 6 that controls the spiral propulsion mechanism 10 will be described. In the saturation avoidance control system of the control unit 6 in the present embodiment, the inclination angle (gyro angle) θg of the wheel shaft 21a of the flywheel 21 in the CMG mechanism 20 is maintained near 0 [°] which is the initial angle, thereby avoiding the control saturation state where the inclination angle θg reaches the limit angle (for example, ±45 [°]).

[0061] The gyro torque τg generated by the CMG mechanism 20 is as shown in the above-described formula (1). Here, in the above-described attitude control system, the gyro torque τg is controlled so as to cancel the spiral torque τs generated by the spiral propulsion mechanism 10 as the disturbance d. Therefore, the gyro torque τg can be decomposed into an attitude control torque τa (a torque for canceling the attitude change caused by the disturbance Tr other than the spiral torque τs) for making the attitude (rotation angle θc around the y-axis) of the drive device 1 the target attitude (target rotation angle θct = 0 [°]), and a torque τs2 (=-τs) for canceling the spiral torque τs. Thus, the above-described formula (1) can be replaced with the following formula (4).

[0062]

Equation

[0063] As a result, in the saturation avoidance control system of the control unit 6, according to the equation of motion of the formula (4), with the spiral torque τs as the input and the inclination angle (gyro angle) θg of the wheel shaft 21a of the flywheel 21 in the CMG mechanism 20 as the control target of the output, it is a control system for controlling the spiral propulsion mechanism 10.

[0064] Specifically, the control unit 6 acquires the inclination angle (gyro angle) θgr of the wheel shaft 21a of the flywheel 21 from the CMG mechanism 20, and calculates a spiral torque τs for making this gyro angle θgr the target initial angle θgt (= 0 [°]). Then, the control unit 6 controls the attitude change motors 15, 15 of the two drive units 10A, 10B in the spiral propulsion mechanism 10 so that the calculated spiral torque τs is generated, and changes the roller angle θm of each drive roller 11, 11. At this time, the control unit 6 may also control the drive motors 14, 14 as necessary in order to maintain the moving speed (lifting speed) of the drive device 1 in cooperation with the movement control system.

[0065] By changing the roller angle θm of the spiral propulsion mechanism 10 to make the drive rollers 11, 11 in an inclined posture, a spiral torque τs about the y-axis is generated. As a result, in the attitude control system of the control unit 6, a gyro torque τg including τs2 for canceling this spiral torque τs as a disturbance is generated by the CMG mechanism 20. As a result, the inclination angle (gyro angle) θg of the wheel shaft 21a of the flywheel 21 of the CMG mechanism 20 approaches the target initial angle θgt (= 0 [°]) more than when it does not include τs2 for canceling the spiral torque τs (more than in the case of a configuration where the spiral torque τs is not generated).

[0066] By continuously performing this control at a predetermined time interval, the CMG mechanism 20 will perform attitude control while changing the inclination angle (gyro angle) θg of the wheel shaft 21a in the vicinity of the initial angle of 0 [°]. In this case, according to the attitude control in the vicinity of the initial angle, attitude control can be performed with a larger attitude control torque τg than the attitude control at an angle away from the initial angle. Therefore, the attitude of the drive device 1 can be changed more quickly (with a high reaction speed), and more accurate attitude control becomes possible.

[0067] In this embodiment, the torque generating device that generates the spiral torque τs, which is the saturation avoidance torque, is the spiral propulsion mechanism 10 that can generate the saturation avoidance torque without using the gyroscopic effect. Different from the CMG mechanism 20, such a spiral propulsion mechanism 10 can continuously generate a saturation avoidance torque in a fixed direction around the y-axis. Therefore, the avoidance control (saturation avoidance control) of the control saturation state of the CMG mechanism 20 by the saturation avoidance torque (spiral torque τs) can be continuously executed.

[0068] Next, the results of the effect confirmation test of the saturation avoidance control in this embodiment will be described. In this effect confirmation test, the driving device 1 is moved up and down along the wire rope 100 extending in the vertical direction from the ground to a height of 20 m at a speed of 1 [m] per second. The CMG mechanism 20 performs attitude control of the driving device 1 so that the rotational angle error of the driving device 1 around the y-axis is maintained at 0 [°]. In the CMG mechanism 20 of this driving device 1, when the inclination angle (gyro angle) θg of the wheel shaft 21a of the flywheel 21 reaches ±45 [°], it enters a control saturation state. In this effect confirmation test, in order to make the control saturation state of the CMG mechanism 20 more likely to occur, the target rotational angle θct of the driving device 1 around the y-axis is changed at 5 [°] per second (so that the driving device 1 moves up and down while slowly rotating around the wire rope 100), and the driving device 1 is controlled for movement.

[0069] FIG. 9 is a graph comparing the rotational angle θc of the driving device 1 around the y-axis when attitude control is performed by the CMG mechanism 20 with the saturation avoidance control system turned on and when attitude control is performed by the CMG mechanism 20 with the saturation avoidance control system turned off. FIG. 10 is a graph comparing the inclination angle (gyro angle) θg of the wheel shaft 21a in the CMG mechanism 20 when attitude control is performed by the CMG mechanism 20 with the saturation avoidance control system turned on and when attitude control is performed by the CMG mechanism 20 with the saturation avoidance control system turned off.

[0070] As shown in Fig. 10, when the saturation avoidance control system is off, the inclination angle (gyro angle) θg of the wheel shaft 21a in the CMG mechanism 20 reaches -45 [°] about 10 seconds after the start of the test, entering a control saturation state. As a result, as shown in Fig. 9, the rotation angle θc of the drive device 1 around the y-axis deviates from the target rotation angle θct about 10 seconds after the start of the test.

[0071] On the other hand, when the saturation avoidance control system is on, as shown in Fig. 10, the inclination angle (gyro angle) θg of the wheel shaft 21a in the CMG mechanism 20 is maintained within an angular range of approximately ±30 [°] from the start to the end of the test and does not reach -45 [°]. As a result, as shown in Fig. 9, the rotation angle θc of the drive device 1 around the y-axis is maintained without deviating from the target rotation angle θct from the start to the end of the test, and high-precision attitude control is performed.

[0072] In this embodiment, the spiral propulsion mechanism 10, which is a moving mechanism for moving the drive device 1, a self-propelled mobile device, along the wire rope 100, is used as a torque generating device for generating a saturation avoidance torque (spiral torque τs), but it is not limited to this. For example, a moving mechanism for moving the drive device 1 along the wire rope 100 by the drive rollers 11, 11 fixed in the orthogonal posture shown in Fig. 4(a) may be provided, and separately, a torque generating device for generating a saturation avoidance torque around the axis (y-axis) of the wire rope 100 may be provided. As the torque generating device in this case, for example, a rotation mechanism for rotating the drive device 1 around the axis of the wire rope 100 by the drive rollers 11, 11 fixed in the parallel posture shown in Fig. 4(c) can be adopted. In this case, by driving and controlling these drive rollers 11, 11, the rotation speed of the drive rollers 11, 11 can be changed, or the rotation direction of the drive rollers 11, 11 can be switched between forward and reverse to obtain a desired saturation avoidance torque.

[0073] Also, in the present embodiment, the saturation avoidance control system of the control unit 6 may always execute saturation avoidance control while the attitude control system that controls the CMG mechanism 20 is being executed, or there may be a period during which saturation avoidance control is not executed while the attitude control system is being executed.

[0074] For example, the spiral propulsion mechanism 10 generates both a moving force for moving along the wire rope 100 and a spiral torque τs (saturation avoidance torque) by the drive roller 11. Therefore, when the rotational speed of the drive roller 11 is low, the generated spiral torque τs is also small, and it is difficult to stably stabilize the inclination angle (gyro angle) θg of the wheel axis 21a of the CMG mechanism 20 at the initial angle (0 [°]), and the behavior of the drive device 1 is likely to become unstable. Therefore, when the rotational speed of the drive roller 11 is low (for example, during the movement start period of the drive device 1 (the acceleration period to the desired movement speed (lifting speed)) or the movement end period of the drive device 1 (the deceleration period)), the saturation avoidance control system may be turned off so as not to execute saturation avoidance control.

[0075] Also, for example, until the inclination angle (gyro angle) θg of the wheel axis 21a of the CMG mechanism 20 deviates from the initial angle (0 [°]) by a predetermined angle or more (while within the range less than the predetermined angle), the saturation avoidance control system may be turned off so as not to execute saturation avoidance control. In this case, until the inclination angle (gyro angle) θg of the wheel axis 21a of the CMG mechanism 20 deviates from the initial angle (0 [°]) by a predetermined angle or more, there is no saturation avoidance torque (spiral torque τs) treated as an external disturbance d. Therefore, the CMG mechanism 20 can execute attitude control without being inhibited by the saturation avoidance torque, and it becomes possible to realize more accurate attitude control. And even in this case, if the inclination angle (gyro angle) θg of the wheel axis 21a of the CMG mechanism 20 deviates from the initial angle (0 [°]) by a predetermined angle or more, saturation avoidance control is executed, so that it is possible to avoid the CMG mechanism 20 from entering a control saturation state.

[0076] Also, in the saturation avoidance control system of this embodiment, the inclination angle (gyro angle) θgr of the wheel shaft 21a of the flywheel 21 is acquired from the CMG mechanism 20, and the spiral propulsion mechanism 10 is feedback-controlled based on the acquisition result. Since a certain time lag occurs in the feedback control, it may be difficult to quickly approach the inclination angle (gyro angle) θg of the wheel shaft 21a to the initial angle.

[0077] In such a case, for example, the control target value θgt of the inclination angle (gyro angle) of the wheel shaft 21a may be acquired from the CMG mechanism 20 during attitude control, and the spiral propulsion mechanism 10 may be feedforward-controlled based on this control target value θgt. According to this, it is possible to quickly approach the inclination angle θg of the wheel shaft 21a in the CMG mechanism 20 to the initial angle.

[0078] In this embodiment, an example in which the CMG mechanism 20 performs attitude control of the drive device 1 so that the rotational position of the drive device 1 around the axis of the wire rope 100 does not change (the target rotational position is fixed at 0°) has been described, but it is not limited to this. For example, the CMG mechanism 20 may perform attitude control of the drive device 1 so that the rotational position of the drive device 1 follows a target rotational position that changes with time around the axis of the wire rope 100. With such attitude control, the drive device 1 can move up and down (move in a spiral shape) along the wire rope 100 while rotating around the axis of the wire rope 100.

[0079] As an example of the use of such a movement mode, for example, a wire rope is passed through a tubular object such as a chimney, and the drive device 1 is moved along the wire rope while rotating around the axis of the wire rope, and an example in which the inner peripheral surface of the tubular object is inspected by an inspection device (such as an imaging device) on the drive device 1 can be cited.

[0080] For example, a wire rope is arranged in a fish farm in the sea, and the driving device 1 is moved along the wire rope while rotating around the axis of the wire rope, and the growth status of the cultured fish in the fish farm is inspected by an inspector (such as an imaging device) on the driving device 1 by looking around the fish farm horizontally by 360°.

[0081] For another example, a wire rope is arranged in an orchard, and the driving device 1 is moved along the wire rope while rotating around the axis of the wire rope, and the growth status of the fruit trees in the orchard is inspected by an inspector (such as an imaging device) on the driving device 1 by looking around the orchard horizontally by 360°.

Explanation of Signs

[0082] 1: Driving device 2: Body frame 3, 4: Rope holding mechanism 5: Power supply unit 6: Control unit 10: Spiral propulsion mechanism 10A, 10B: Driving part 11: Driving roller 12: Support frame 13: Roller frame 14: Driving motor 15: Motor for attitude change 20: CMG mechanism 21: Flywheel 21a: Wheel shaft 22: Support frame 23: Wheel frame 24: Wheel driving motor 25: Gimbal 25a: Gimbal motor 26: Encoder 100: Wire rope

Claims

1. A saturation avoidance control device that executes saturation avoidance control for avoiding control saturation of a control moment gyro during attitude control of an attitude control target, having a torque control unit that controls a torque generation device that generates a saturation avoidance torque coaxial with the attitude control torque generated by the control moment gyro during attitude control without using the gyro effect, wherein the torque control unit controls the saturation avoidance torque such that the attitude change of the attitude control target due to the saturation avoidance torque approaches an initial angle of an inclination angle of a wheel axis of the control moment gyro during attitude control. The saturation avoidance control device is characterized by this.

2. In the saturation avoidance control device according to Claim 1, the torque generation device is a non-saturated configuration capable of continuously generating the saturation avoidance torque. The saturation avoidance control device is characterized by this.

3. In the saturation avoidance control device according to Claim 2, the attitude control by the control moment gyro controls the rotational position of the attitude control target around the axis of a predetermined elongated member, the torque generation device includes a drive rotating body that contacts the circumferential surface of the elongated member and rotates the attitude control target around the axis of the elongated member, and an axis angle changing unit that changes the angle of the rotation axis of the drive rotating body with respect to the axis of the elongated member, wherein the torque control unit controls the saturation avoidance torque by controlling the axis angle changing unit to change the angle of the rotation axis of the drive rotating body. The saturation avoidance control device is characterized by this.

4. In the saturation avoidance control device according to Claim 2 or 3, the attitude control by the control moment gyro controls the rotational position of the attitude control target around the axis of a predetermined elongated member, the torque generation device includes a drive rotating body that contacts the circumferential surface of the elongated member and rotates the attitude control target around the axis of the elongated member, wherein the torque control unit controls the saturation avoidance torque by controlling the drive of the drive rotating body. The saturation avoidance control device is characterized by this.

5. In the saturation avoidance control device according to any one of Claims 1 to 3, the torque control unit continuously controls the saturation avoidance torque at predetermined time intervals. The saturation avoidance control device is characterized by this.

6. In the saturation avoidance control device according to any one of Claims 1 to 3, The torque control unit performs control of the saturation avoidance torque when the inclination angle of the wheel axis of the control moment gyro during attitude control deviates from the initial angle by a predetermined angle or more, and does not perform control of the saturation avoidance torque when it is within a range less than the predetermined angle from the initial angle. A saturation avoidance control device characterized by this.

7. In the saturation avoidance control device according to any one of claims 1 to 3, The torque control unit acquires a control target value of the control moment gyro during attitude control, and performs control of the saturation avoidance torque using the control target value. A saturation avoidance control device characterized by this.

8. An attitude control device that performs attitude control of an attitude control target using a control moment gyro, A torque generator that generates a saturation avoidance torque coaxial with the attitude control torque generated by the control moment gyro during attitude control without using the gyro effect, A saturation avoidance control device that executes saturation avoidance control for avoiding control saturation of the control moment gyro during attitude control of the attitude control target, and As the saturation avoidance control device, an attitude control device characterized by using the saturation avoidance control device according to any one of claims 1 to 3.

9. A self-propelled mobile device that moves along the path member by the rotational driving force of a driving rotating body that contacts the peripheral surface of the elongated path member, Comprising a shaft angle changing unit that changes the angle of the rotation axis of the driving rotating body with respect to the axis of the path member, As an attitude control device that performs attitude control for controlling the rotational position of the self-propelled mobile device around the axis of the path member, the attitude control device according to claim 8 is used, As the saturation avoidance control device, the saturation avoidance control device according to claim 3 is used, The torque control unit performs control of the saturation avoidance torque by controlling the shaft angle changing unit to change the angle of the rotation axis of the driving rotating body. A self-propelled mobile device characterized by this.

10. In the self-propelled mobile device according to claim 9, The attitude control by the control moment gyro is characterized in that it controls the rotational position of the self-propelled mobile device to follow a target rotational position that changes with time around the axis of the path member. A self-propelled mobile device characterized by this.

11. A saturation avoidance control method for avoiding control saturation of a control moment gyro during attitude control of an attitude control target, controlling a torque generator that generates a saturation avoidance torque coaxial with the attitude control torque generated by the control moment gyro during attitude control without using the gyro effect, and controlling the saturation avoidance torque so that the attitude change of the attitude control target due to the saturation avoidance torque approaches the inclination angle of the wheel axis of the control moment gyro during attitude control to an initial angle. The saturation avoidance control method is characterized by this.

Images