Mobile device and mobile object

Abstract

To provide a movement device which realizes height adjustment of a carrying platform and getting-over of a step and a slope of a wheel with a minimum energy loss and can be miniaturized with a simple configuration.SOLUTION: A movement device comprises: a base body 1; a carrying platform 5 on which a loading object W is loaded; a carrying platform support part 2 which is vertically movable; a wheel 3 which has a rotational shaft; a non-stage transmission which performs non-stage transmission of a transmission ratio of the rotational shaft of the wheel 3 to a first output shaft; a differential mechanism which has a second output shaft that is connected with the first output shaft of the non-stage transmission and the rotational shaft of the wheel 3 and rotates at a rotation frequency according to a rotational speed difference between the rotational shaft of the wheel 3 and the first output shaft; a rotation-linear motion conversion mechanism which converts the rotation of the second output shaft of the differential mechanism into the vertical linear motion to transmit it to the carrying platform support part 2; and a control device 6 which controls the transmission ratio such that the carrying platform 5 becomes horizontal according to the slop and step height of the ground surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a moving device and a moving body that support and move a transport platform. [Background technology]

[0002] In an article transport device, unevenness in the ground, such as unevenness, gradients, and irregularities, can cause vibrations in the platform, causing it to shift in position and resulting in poor transport quality. If the platform's height relative to the inertial coordinate system could be kept constant and the platform's position could be kept horizontal regardless of ground displacement, stable and ideal transport would be possible, even when liquids, food, or other items are transported without quality degradation. However, in a transport device that travels on the ground, the platform support serves as a load path for the weight of the payload, making it difficult to expand and contract the platform support in response to ground displacement. Specifically, these approaches require either an inefficient configuration in which the vertical load acts directly on the actuator, a spring support system that creates a trade-off between robustness to changes in the center of gravity position and adaptability to ground displacement, or a complex load compensation mechanism that can adjust the compensation value to match the payload.

[0003] Non-patent document 1 shows a wheel unit having a mobile base with front steering wheels and left and right drive wheels, a vehicle body tilting mechanism, and stepping motors that drive the front steering wheels, left and right drive wheels, and vehicle body tilting mechanism, respectively. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Masafumi Hashimoto and two others, "Study on the driving control of an omnidirectional mobile robot with a body tilting mechanism", Journal of the Japan Society for Precision Engineering, Vol. 70, No. 7, 2004, pp. 983-988 Summary of the Invention [Problem to be solved by the invention]

[0005] In Non-Patent Document 1, the mobile base with front steering wheels and left and right drive wheels and the vehicle body tilting mechanism are configured separately, and the energy balance between the mobile base and the vehicle body tilting mechanism is not taken into consideration. Instead, the mobile base and vehicle body tilting mechanism are driven by a stepping motor, which is an electrical actuator. For this reason, Non-Patent Document 1 cannot achieve horizontal movement with zero power due to Joule loss associated with static thrust and low conversion efficiency. Furthermore, Non-Patent Document 1 has the problem of a complicated configuration and a large device.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a mobile device that has a simple configuration and can be made compact, and that can adjust the height of the transport platform and enable wheels to overcome steps and slopes with minimal energy loss. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the moving device of the present disclosure includes a base body, a conveyance platform on which an object is placed, a conveyance platform support section that is movable up and down relative to the base body and that supports the conveyance platform, wheels having a rotational shaft that is rotatable relative to the base body, a first input shaft to which the rotational shaft of the wheels is connected, and a first output shaft, a continuously variable transmission that continuously changes the gear ratio between the first input shaft and the first output shaft, a differential mechanism that connects the first output shaft of the continuously variable transmission and the rotational shaft of the wheels, and has a second output shaft that rotates at a rotation speed corresponding to the difference in rotational speed between the first output shaft and the rotational shaft, a rotary-linear motion conversion mechanism that converts the rotation of the second output shaft of the differential mechanism into vertical linear motion and transmits it to the conveyance platform support section, and a rotation-linear motion conversion mechanism that converts the rotation of the second output shaft of the differential mechanism into vertical linear motion and transmits it to the conveyance platform support section, and a tilt of the ground. and Step height At least one of and a control device that controls the speed ratio so that the conveying platform is horizontal depending on the speed. [Effects of the Invention]

[0008] The moving device of the present disclosure has the advantage of being able to adjust the height of the transport platform and enable the wheels to overcome steps and slopes with minimal energy loss, and to provide a moving device that can be made compact with a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration example of a moving device according to a first embodiment; [Figure 2] FIG. 1 is a schematic diagram illustrating a configuration example of a mechanical coupling unit of a moving device according to a first embodiment; [Figure 3] FIG. 1 is a diagram illustrating a state in which the moving device according to the first embodiment travels on flat ground. [Figure 4] FIG. 1 is a diagram illustrating a state in which the moving device according to the first embodiment travels uphill; [Figure 5] FIG. 1 is a diagram illustrating a state in which the moving device according to the first embodiment travels downhill; [Figure 6] FIG. 10 is a schematic diagram illustrating another configuration example of the mechanical coupling unit of the movement device according to the first embodiment; [Figure 7] FIG. 10 is a top view illustrating a configuration example of a moving object according to a fourth embodiment. [Figure 8] FIG. 10 is a side view showing a configuration example of a moving object according to a fourth embodiment; [Figure 9] FIG. 13 is a schematic diagram illustrating a configuration example of a moving object according to a fifth embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0010] A moving device and a moving body according to an embodiment will be described in detail below with reference to the drawings.

[0011] Embodiment 1 1 is a schematic diagram showing a configuration example of a moving device 20 according to the first embodiment. The moving device 20 includes a base 1, a carriage support unit 2, wheels 3, a mechanical coupling unit 4, a carriage 5, and a control device 6. A payload W to be transported by the moving device 20 is mounted on the carriage 5.

[0012] The transport platform support part 2 is capable of moving up and down in the direction of arrow K relative to the base 1. The wheels 3 are rotatable relative to the base 1. The mechanical coupling part 4 mechanically couples the base 1 and the transport platform support part 2. The mechanical coupling part 4 exchanges mechanical energy between the up and down movement of the transport platform support part 2 and the rotational movement of the wheels 3. The mechanical coupling part 4 changes the motion ratio G between the up and down movement of the transport platform support part 2 and the rotational movement of the wheels 3. The control device 6 executes control to adjust the motion ratio G at the mechanical coupling part 4.

[0013] When the moving device 20 approaches a step or an incline, the control device 6 actively adjusts the motion ratio G between the up and down movement of the conveying platform support part 2 and the rotational movement of the wheels 3 to a value proportional to the step height or incline angle, thereby simultaneously performing the up and down movement of the conveying platform support part 2 and generating torque in the wheels 3, thereby achieving both stabilization of the conveying platform 5 and the ability to overcome the step or incline without the need for external force, and realizing an operation as if the load W were moving horizontally.

[0014] If the weight of the wheels 3 and the parts that move in conjunction with the wheels 3 are sufficiently small compared to the weight of the payload W, the potential energy of the payload W remains unchanged, and the mechanical coupling 4 maintains an energy balance between the carrier support 2 and the wheels 3. Therefore, if the motion ratio G between the vertical movement of the carrier support 2 and the rotational movement of the wheels 3 is controlled to a value that makes the payload W move as if it were moving horizontally, the moving device 20 can theoretically go over steps and slopes without consuming energy.

[0015] If the load of the payload W is F, the extension / retraction speed, which is the vertical movement speed of the carrier support unit 2, is v, the torque generated by the wheels 3 is τ, and the angular velocity of the wheels 3 is ω, then F·v=τ·ω holds due to the action of the mechanical coupling unit 4. Here, the load F of the payload W is known because it is determined by the weight of the payload W, and under the assumption that the speed of the moving device 20 (corresponding to the angular velocity ω of the wheels 3) is known, adjusting the operating ratio G corresponds to adjusting the extension / retraction speed v of the carrier support unit 2 and also corresponds to adjusting the torque τ generated by the wheels 3.

[0016] When the operating ratio G is adjusted in proportion to the inclination angle of the ground, the ground inclination becomes v / (rω) where r is the radius of the wheel 3, and the torque τ generated by the wheel 3 at this time is unintentionally adjusted to a value that simply maintains balance on the inclined ground when carrying the weight of the load W. In other words, simply by adjusting the operating ratio G to a value proportional to the inclination angle of the ground, the extension / retraction speed v of the carrier support unit 2 becomes a value proportional to the speed of the moving device 20, making it possible to maintain the load W horizontally, and at the same time, the torque τ generated by the wheel 3 cancels out the thrust required to traverse steps and inclines when carrying the weight of the load W.

[0017] Suppose the mobile device 20 approaches a convex part on the ground. If the operating ratio G is adjusted to an appropriate value, the wheels 3 will generate the torque required to climb the slope, and the device will be in a balanced state on the upslope. At this time, the energy required to propel the mobile device 20 is zero. This is because, assuming that there is zero energy loss in the mechanical system and the weight of elements other than the payload W can be ignored, the energy used by the wheels 3 to climb the slope is equal to the energy used to move the carrier support unit 2 up and down, and there is no change in the total energy. The opposite situation occurs when the mobile device 20 approaches a concave part on the ground. If the operating ratio G is adjusted to an appropriate value, the wheels 3 will generate a torque to descend the slope, and the device will be in a balanced state on the downslope. In this case, the energy required to propel the mobile device 20 is also zero.

[0018] In this way, the control device 6 adjusts the operating ratio G at the mechanical coupling part 4 so that the conveying platform 5 is level according to the slope of the ground and the height of the step, thereby making it possible to adjust the height of the conveying platform 5 and enable the wheels 3 to overcome steps and slopes with minimal energy loss.

[0019] FIG. 2 is a schematic diagram showing an example of the configuration of the mechanical coupling unit 4 of the transport device 20 according to the first embodiment. FIG. 2 shows the configuration of the mechanical coupling unit 4 when the transport device 20 of FIG. 1 is viewed from above. The mechanical coupling unit 4 is a mechanical element that connects the carriage support unit 2 and the wheels 3 with a variable operating ratio G. The mechanical coupling unit 4 includes a continuously variable transmission 7, a rotary-to-linear motion conversion mechanism 8, a differential gear 9 as a differential mechanism, and a speed increaser 10. The rotary-to-linear motion conversion mechanism 8 is connected to the carriage support unit 2. The double circle with a black circle and the circle with an x ​​shown at the lower right of the rotary-to-linear motion conversion mechanism 8 indicate that the output shaft of the rotary-to-linear motion conversion mechanism 8 moves in the vertical direction (perpendicular to the plane of the paper).

[0020] The input shaft of the differential gear 9 is connected to the rotating shaft 3a of the wheels 3 and the output shaft 7b of the continuously variable transmission 7. The output shaft 9e of the differential gear 9 is connected to the rotary-linear motion conversion mechanism 8. The output shaft 9e corresponds to the second output shaft. When a difference in rotational speed occurs between the wheels 3 and the output of the continuously variable transmission 7, the differential gear 9 rotates at a rotational speed corresponding to the rotational speed difference. The differential gear 9 has a first side gear 9a, a second side gear 9b, a first pinion gear 9c, and a second pinion gear 9d. The first side gear 9a is connected to the output shaft 7b of the continuously variable transmission 7. The second side gear 9b is connected to the rotating shaft 3a of the wheels 3. The first pinion gear 9c is terminated. The second pinion gear 9d is connected to the output shaft 9e. The second pinion gear 9d is connected to the rotary-linear motion conversion mechanism 8 via the output shaft 9e.

[0021] The rotary-linear motion conversion mechanism 8 converts the rotation of the output shaft 9e of the differential gear 9 into vertical linear motion. The rotary-linear motion conversion mechanism 8 can be a rack and pinion mechanism or a belt winding mechanism.

[0022] The continuously variable transmission 7 is a power transmission mechanism that continuously changes the gear ratio G between the input shaft 7a (the first input shaft) and the output shaft 7b (the first output shaft). The gear ratio G corresponds to the operating ratio G described above. A speed-up gear 10 is provided between the continuously variable transmission 7 and the rotating shaft 3a of the wheels 3 to operate the continuously variable transmission 7 at or below the allowable torque. The speed-up gear 10 increases the rotational speed of the rotating shaft 3a of the wheels 3 and inputs the increased speed to the continuously variable transmission 7. The continuously variable transmission 7 may be, for example, a zero-max type continuously variable transmission using a swing link and a one-way clutch. The zero-max type continuously variable transmission is a one-way clutch type continuously variable transmission that can instantly change speeds from zero to maximum speed. It is characterized by its small size, light weight, and smooth gear-shifting operation. This avoids a significant increase in the weight of the wheels 3, and allows for the use of a small radio-controlled servo for gear-shifting, enabling electrical control. Furthermore, it is expected that the efficiency of the speed-increasing mechanism will be increased by using highly efficient gears as the speed-increasing gear 10. As highly efficient gears, a compound planetary gear mechanism can be used.

[0023] Fig. 3 is a diagram showing a state in which the moving device 20 according to the first embodiment travels on flat ground, Fig. 4 is a diagram showing a state in which the moving device 20 according to the first embodiment travels uphill, and Fig. 5 is a diagram showing a state in which the moving device 20 according to the first embodiment travels downhill.

[0024] 3, when traveling on flat ground 30, if the control device 6 sets the speed ratio G of the continuously variable transmission 7 equal to the speed-up ratio G0 of the speed-up gear 10, the rotation speed of the wheels 3 and the rotation speed of the output shaft 7b of the continuously variable transmission 7 will match, and the output shaft 9e of the differential gear 9 will not rotate. As a result, the rotary-to-linear motion conversion mechanism 8 will not operate, and the conveyance platform support part 2 and the conveyance platform 5 will maintain a constant height.

[0025] As shown in Figure 4, when traveling on an uphill ground surface 30, the control device 6 increases the speed ratio G of the continuously variable transmission 7 to a value proportional to the inclination angle of the ground surface 30. As a result, the rotation speed of the output shaft 7b of the continuously variable transmission 7 decreases relative to the rotation speed of the wheels 3, the height of the platform support part 2 and the platform 5 decreases as shown by arrow K1, the loaded load W moves horizontally, and a positive torque τ acts on the wheels 3, generating a driving force sufficient to counteract the uphill gradient.

[0026] As shown in Figure 5, when traveling on a downhill ground surface 30, the control device 6 reduces the speed ratio G of the continuously variable transmission 7 to a value proportional to the inclination angle of the ground surface 30. As a result, the rotation speed of the output shaft 7b of the continuously variable transmission 7 increases relative to the rotation speed of the wheels 3, the height of the platform support part 2 and the platform 5 rises as shown by arrow K2, the loaded load W moves horizontally, and a negative torque τ acts on the wheels 3, generating a braking force sufficient to counteract the downward gradient.

[0027] FIG. 6 is a schematic diagram showing another example of the mechanical coupling unit 4 of the movement device 20 according to the first embodiment. The mechanical coupling unit 4 shown in FIG. 6 uses a planetary gear 11 as a differential mechanism. The planetary gear 11 includes a sun gear 11a, a planetary gear 11b, an internal gear 11c, and a carrier 11d as a rotation support frame. In the planetary gear 11, if none of the sun gear 11a, planetary gear 11b, and internal gear 11c elements are fixed, and two elements are connected to the rotating shaft 3a of the wheel 3 and the output shaft 7b of the continuously variable transmission 7, the movement of the remaining element functions as a differential gear. In the case of FIG. 6, the rotating shaft 3a of the wheel 3 is connected to the internal gear 11c, the output shaft 7b of the continuously variable transmission 7 is connected to the sun gear 11a, and the carrier 11d is connected to the rotary-linear motion conversion mechanism 8.

[0028] According to the first embodiment, the wheels 3 and the platform support 2 are mechanically coupled via the continuously variable transmission 7, the differential mechanism, and the rotary-to-linear motion conversion mechanism 8. If the energy loss in the mechanical system including the wheels 3, the continuously variable transmission 7, the differential mechanism, the rotary-to-linear motion conversion mechanism 8, and the platform support 2 is sufficiently small, it can be considered that energy is being exchanged between the wheels 3 and the platform support 2, and the magnitude and direction of this energy are being adjusted by the continuously variable transmission 7. As described above, in the first embodiment, energy is exchanged between the wheels 3 and the platform support 2, and the speed ratio G between the vertical movement of the platform support 2 and the rotational movement of the wheels 3 is variable by the continuously variable transmission 7 to match the shape of the ground. This makes it possible to overcome steps and inclines and stabilize the posture of the load W, regardless of the ground gradient, with minimal energy loss. Furthermore, since the wheels 3 and the platform support 2 are not configured to be driven independently, but rather only the speed ratio G of the continuously variable transmission 7 is controlled, the device configuration is simplified and compact.

[0029] Embodiment 2 If hydraulic or pneumatic equipment is used for the mechanical coupling unit 4 described in the first embodiment, it will be possible to support a heavy load W. When hydraulic equipment is used, a hydrostatic transmission (HST) or a hydromechanical transmission (HMT) may be used as the continuously variable transmission 7 that changes the operating ratio G. When pneumatic equipment is used, a combination of a direct acting pneumatic cylinder, a pneumatic pump, and a pneumatic valve may be used.

[0030] Embodiment 3 In the moving device 20 described in the first and second embodiments, the wheels 3 may be drive wheels or driven wheels. If the wheels 3 are drive wheels, a drive power source such as a motor is provided to the wheels 3, and if they are driven wheels, no drive power source is provided to the wheels 3 and they are driven by an external force. The moving device 20 may be provided with an elastic body that absorbs shock when going over steps.

[0031] Embodiment 4 FIG. 7 is a top view showing a configuration example of a moving body 40 according to the fourth embodiment. FIG. 8 is a side view showing a configuration example of a moving body 40 according to the fourth embodiment. In the moving body 40 according to the fourth embodiment, the moving device 20 described in the first to third embodiments is regarded as one unit support mechanism 20′, and a plurality of moving devices 20 are used to support the conveyance platform 5, thereby enabling both stabilization of the posture of the conveyance platform 5 and its ability to overcome steps and inclines. In other words, the conveyance platform 5 is provided across a plurality of unit support mechanisms 20′. By combining a unit support mechanism 20′ using wheels 3 as driving wheels with a unit support mechanism 20′ using wheels 3 as driven wheels, it is possible to realize a moving body 40 that can move autonomously and stabilize its posture. Various types of moving body 40 are conceivable, such as a combination of driving wheels and driven wheels, and a swivel type.

[0032] Embodiment 5 FIG. 9 is a schematic diagram showing a configuration example of a moving body 50 according to a fifth embodiment. The moving body 50 includes an image sensor 12 and an inertial sensor 13. The image sensor 12, which serves as a first sensor, captures an image of the area ahead of the moving body 50. The control device 6 calculates the height of a step on the ground ahead and the inclination angle of the ground based on the image data captured by the image sensor 12. The inertial sensor 13 measures the acceleration or angular velocity of the moving body 50. An acceleration sensor, a gyro sensor, or the like is used as the inertial sensor 13.

[0033] The control device 6 adjusts the operation ratio G of each of the plurality of unit support mechanisms 20' by feedforward or feedback to a value proportional to the step height or inclination angle of the ground, based on the height of the step on the ground ahead calculated from the image data of the image sensor 12 and the inclination angle of the ground, and the acceleration or angular velocity information from the inertial sensor 13. That is, the control device 6 controls the gear ratio G so that the conveyance platform 5 is level according to the inclination of the ground and the step height, based on the detection outputs of the image sensor 12 and the inertial sensor 13. An inclinometer may be used as the first sensor for detecting the inclination of the ground and the step height.

[0034] According to the fifth embodiment, sensors are provided for measuring the height of steps and the inclination angle of the ground, so that it is possible to fully automate the height adjustment of the platform 5 and the wheels 3 climbing over steps and inclines.

[0035] The configurations shown in the above embodiments are examples of the contents of the present disclosure, and may be combined with other known technologies, and parts of the configurations may be omitted or modified within the scope of the gist of the present disclosure.

[0036] Various aspects of the present disclosure are summarized below as appendices.

[0037] (Appendix 1) a substrate; a transport platform on which the payload is placed; a carriage support portion that is movable up and down relative to the base and supports the carriage; a wheel having a rotation axis rotatable relative to the base body; a continuously variable transmission having a first input shaft to which the rotation shaft of the wheel is connected and a first output shaft, and continuously changing a gear ratio between the first input shaft and the first output shaft; a differential mechanism having a second output shaft to which the first output shaft of the continuously variable transmission and the rotating shaft of the wheel are connected and which rotates at a rotation speed corresponding to a rotation speed difference between the first output shaft and the rotating shaft; a rotation-linear motion conversion mechanism that converts the rotation of the second output shaft of the differential mechanism into vertical linear motion and transmits the linear motion to the conveyance table support portion; a control device that controls the speed ratio so that the conveying platform is level according to the inclination of the ground and the height of steps; A mobile device comprising: (Appendix 2) 2. The moving device according to claim 1, further comprising a speed increaser between the wheel and the first input shaft of the continuously variable transmission, the speed increaser increasing the rotational speed of the wheel. (Appendix 3) 3. The moving device according to claim 1, wherein the continuously variable transmission is a one-way clutch type continuously variable transmission capable of changing speeds from zero revolutions to maximum revolutions. [Explanation of symbols]

[0038] 1 base, 2 carrier support part, 3 wheel, 3a rotating shaft, 4 mechanical coupling part, 5 carrier, 6 control device, 7 continuously variable transmission, 7a input shaft, 7b, 9e output shaft, 8 rotary-linear conversion mechanism, 9 differential gear, 9a first side gear, 9b second side gear, 9c first pinion gear, 9d second pinion gear, 10 speed increaser, 11 planetary gear, 11a sun gear, 11b planetary gear, 11c internal gear, 11d carrier, 12 image sensor, 13 inertial sensor, 20 moving device, 20' unit support mechanism, 30 ground, 40, 50 moving body, W mounted object.

Claims

1. a substrate; a transport platform on which the payload is placed; a carriage support portion that is movable up and down relative to the base and supports the carriage; a wheel having a rotation axis rotatable relative to the base body; a continuously variable transmission having a first input shaft to which a rotation shaft of the wheel is connected and a first output shaft, the continuously variable transmission continuously changing a gear ratio between the first input shaft and the first output shaft; a differential mechanism having a second output shaft to which the first output shaft of the continuously variable transmission and the rotating shaft of the wheel are connected and which rotates at a rotation speed corresponding to a rotation speed difference between the first output shaft and the rotating shaft; a rotation-to-linear motion conversion mechanism that converts the rotation of the second output shaft of the differential mechanism into vertical linear motion and transmits the linear motion to the conveyance table support portion; a control device that controls the speed ratio so that the platform is level in accordance with at least one of the slope of the ground and the height of a step; A mobile device comprising:

2. 2. The moving device according to claim 1, further comprising a speed increaser between the wheel and the first input shaft of the continuously variable transmission, the speed increaser increasing the rotational speed of the wheel.

3. 2. The moving device according to claim 1, wherein the continuously variable transmission is a one-way clutch type continuously variable transmission capable of changing the speed from zero revolutions to maximum revolutions.

4. A plurality of the moving devices according to any one of claims 1 to 3 are provided, A moving body characterized in that the transport platform is provided across a plurality of moving devices.

5. a first sensor for detecting the inclination of the ground and the height of a step; The moving body according to claim 4, characterized in that the control device controls the gear ratio so that the conveying platform is level in accordance with at least one of the inclination of the ground and the height of a step, based on the detection output of the first sensor.

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