JP2006068883A - Robot device and its control method, and passive wheel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leg and wheel hybrid type robot device having both characteristics of the leg-type movement and the wheel-type movement. <P>SOLUTION: A passive wheel mechanism with an oscillating caster is mounted freely attachably/detachably to/from the tiptoe. A wheel generates oscillating action with friction force between the wheel and a road surface by imparting movement in the Y direction to the tiptoe. A glide angle θ<SB>G</SB>formed by a rolling direction and an advancing direction of the wheel is indirectly formed. Thrust is obtained by converting the movement of the tiptoe in the Y direction to the rotational movement of the wheel on the basis of the anisotrophy of drag that a friction factor in the rolling direction of the wheel is small, however, friction in the axial direction is large. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a robot apparatus including a plurality of movable parts, a control method thereof, and a passive wheel apparatus, and more particularly to a robot apparatus including a moving unit, a control method thereof, and a passive wheel apparatus.

  More particularly, the present invention relates to a leg-wheel hybrid robot apparatus having both the characteristics of a leg-type movement and a wheel-type movement, a control method thereof, and a passive wheel apparatus, and more particularly, a passive wheel is added. The present invention relates to a robot apparatus and a control method thereof that improve running performance by legs, and a passive wheel apparatus.

  A mechanical device that performs a movement resembling human movement using an electrical or magnetic action is called a “robot”. It is said that the word “robot” comes from the Slavic word “ROBOTA (slave machine)”. In Japan, robots started to spread from the end of the 1960s, but many of them are industrial robots such as manipulators and transfer robots for the purpose of automating and unmanned production operations in factories. Met.

  Recently, research and development on legged mobile robots simulating the body mechanism and movement of animals such as humans and monkeys who perform biped upright walking has progressed, and expectations for practical use are also increasing (for example, Patent Document 1). checking). Leg type movement with two legs standing up is unstable and difficult to control posture and walking, compared to crawler type, four or six legs type, etc., but walking with irregularities on the work path such as rough terrain and obstacles It is excellent in that it can realize flexible movement work, such as being able to cope with discontinuous walking surfaces such as up and down of surfaces and stairs and ladders.

  Most of the human working space and living space are formed according to the human body mechanism and behavioral style of biped upright walking, and the current mechanical system using wheels and other driving devices as moving means moves. There are many barriers. Therefore, in order for the mechanical system, that is, the robot to perform various human tasks and penetrate deeply into the human living space, it is preferable that the movable range of the robot is substantially the same as that of the human. This is also why the practical application of legged mobile robots is highly expected.

  However, a legged mobile robot has high ground adaptability, but has a problem that it is inferior to a wheeled mobile robot in terms of moving speed and efficiency. For this reason, so-called leg-wheel hybrid type moving bodies that combine the characteristics of both leg-type movement and wheel-type movement have been studied.

  As a mobile robot using wheels, for example, a six-legged traveling vehicle for extreme work (for example, see Non-Patent Document 1) or a moving body (for example, see Non-Patent Document 2) for entering a disaster site. In addition, if the crawler is also regarded as a wheel in a broad sense from the viewpoint of using a continuous endless track, COMET-III (for example, see Non-Patent Document 3) developed for the purpose of removing landmines can be cited. .

  These moving bodies use active wheels having driving force as wheels. On the other hand, a legged walking machine generally has many degrees of freedom in order to realize a walking motion, and the body mass tends to increase. In addition, if an actuator for driving the wheel is mounted, the mass is unnecessarily increased, and as a result, the motion performance as a walking machine is constrained.

  Therefore, a hybrid method for walking machines using passive wheels with a simple mechanism and a small increase in mass has been proposed.

  For example, there has been proposed a legged mobile robot that can realize a moving work that is more dynamic and faster than normal walking motion by wearing roller skates (see, for example, Patent Document 2). .

  In the technique named “roller walker”, passive wheels can be attached to the tip of a leg, and propulsion can be carried out based on the same principle as roller skating (see, for example, Non-Patent Document 4).

  20 and 21 schematically show the degree of freedom configuration of the roller walker. The hybrid walking machine shown in the figure is a four-legged legged mobile robot, and each leg portion has three degrees of freedom around the roll and one degree of freedom around the yaw from the foot toward the base. It has a total of 4 degrees of freedom (however, the robot's forward direction is set as X, and the coordinate system is set as the traveling direction as shown). The foot of the foot has a disk shape and also functions as a wheel. That is, at the time of walking, as shown in FIG. 20, the ankle angle is rotated around the roll, so that the disk-shaped wheel is brought to ground and used as a sole. Further, when traveling using the wheels, as shown in FIG. 21, the ankle angle is rotated around the roll to raise a disk-shaped wheel so that the wheels can be passively rotated around the pitch axis after the ankle. By using such a simple mechanism, an excessive weight increase can be suppressed and performance degradation as a walking machine can be minimized while realizing running performance using wheels.

  In the propulsion by the passive wheel, the rolling direction of the wheel has a small coefficient of friction, and the axial direction has a large amount of friction. By using such anisotropy of the drag, propulsion by passive wheels is realized. Here, for example, by using the yaw axis rotation at the base of the left and right legs, the distance between the left and right wheels in the axial direction expands and contracts while the left and right wheels are inclined with respect to the X direction. At this time, since the friction in the axial direction is large, the frictional force generated in the axial direction of the wheel is released by the rolling of the wheel and is converted into a propulsive force in the X direction.

Here, in order to convert the frictional force in the axial direction of the wheel into rotation of the wheel, it has a mechanism that rotates the rolling direction of the wheel in the yaw direction, and the rolling direction of the wheel is non-orthogonal with respect to the frictional force applied to the wheel. Need to be. Further, the angle θ _G (referred to as the glide angle) formed by the rolling direction of the wheel and the propulsion direction (or the main traveling direction of the robot) corresponds to the reduction ratio of the gear. Therefore, it is possible to generate a large driving force to the propulsion direction of the device from becoming slow I mean a large angle by the glide angle theta _G. Conversely, by giving a small angle to the glide angle θ _G , the robot can be propelled at a high speed although it has a small propulsive force (see, for example, Non-Patent Document 5 and Non-Patent Document 6). That is, in order to generate a movement in a desired direction, it is necessary to change the rolling direction of the wheel, that is, the leg tip yaw angle.

  In general, in the case of a multi-legged walking robot excluding two legs, it is preferable to reduce the weight per leg from the viewpoint of mechanism design. As a result, the degree of freedom per leg is often 3 degrees of freedom of XYZ, and it is actually impossible to handle all 6 degrees of freedom of (X, Y, Z, Roll, Pitch, Yaw) independently. It is.

  In the joint arrangements shown in FIGS. 20 and 21, it is possible to indirectly change the yaw as a dependent variable of the XY position, so that propulsion using passive wheels can be considered. However, the multi-legged robots studied so far are only the joint arrangements shown in FIGS. 20 and 21, and the joint arrangement shown in FIG. 22, for example, has not been studied.

Further, a multi-legged walking robot has been proposed in which the layout of the drive system of the joint part is given freedom and the joint part has sufficient power and rigidity (see, for example, Patent Document 3). ). The movable leg of this robot apparatus has a total of three degrees of freedom, ie, a degree of freedom around the first rotation axis corresponding to the roll axis and a degree of freedom around the second and third rotation axes corresponding to the pitch axis. However, the movable leg does not have a degree of freedom that can generate the yaw rotation of the foot to obtain the glide angle θ _G.

  Since the yaw rotation of the foot to obtain the glide angle cannot be generated while maintaining the three degrees of freedom, the frictional force in the axial direction of the wheel is converted into the rotation of the wheel, or the reduction ratio is adjusted. It is not possible. That is, the conventional method (see Non-Patent Document 5 and Non-Patent Document 6) cannot be applied as it is.

  In addition, as can be seen from FIG. 20 and FIG. 21, the roller walker requires an ankle actuator for switching between the sole and the wheel, and it is necessary to construct the entire system including the sole switching mechanism. is there. In this case, since the sole and the wheel are always used together, it is not always possible to select an appropriate shape and material for walking.

Japanese Patent Laid-Open No. 13-129775 JP 2001-138272 A Japanese Patent Laid-Open No. 2002-11679, FIG. N. Kimura, T. Kamigaki, N. Suzuki, A. Nishikawa and N. Yamamoto: “Locomotion Mechanism and Control Architecture for Disaster Preventing Robot”, '91 ISART pp.375-380 (1991) H.Adachi, N.Koyachi, T.Arai, A.SHimizu and Y.Nogami: “Mechanism and Control of a Leg-Wheel Hybrid Mobile Robot”, International Conference on Intelligent Robots and Systems Proc., Pp.1792-1797 1999) http://mec2.tm.chiba-u.jp/~nonami/ G. Endo, S. Hirose: “Study on Roller-Walker (Multi-mode Steering Control and Self-contained Locomotion”, IEEE International Conference on Robotics and Automation, pp. 2808-2814 (2000) Gen Endo: “Study on glide propulsion in cord-like active vehicle and leg-wheel hybrid vehicle”, Tokyo Institute of Technology Graduate School of Science and Engineering, Department of Mechanical Physics Engineering, pp.8-10 (2000) Gen Endo: “Study on Glide Propulsion in Active Active Vehicles and Leg-Wheel Hybrid Vehicles”, Tokyo Institute of Technology Graduate School of Science and Engineering, Department of Mechanical Physics Engineering, pp.80-87 (2000)

  It is an object of the present invention to provide an excellent leg-wheel hybrid type robot apparatus having both characteristics of a leg-type movement and a wheel-type movement, a control method thereof, and a passive wheel apparatus.

  A further object of the present invention is to provide an excellent robot apparatus, a control method therefor, and a passive wheel apparatus that can improve running performance by legs by adding passive wheels.

  A further object of the present invention is to obtain a driving force by using a passive wheel attached to the tip of the foot, rotating the rolling direction of the wheel around the yaw, and converting the frictional force in the axial direction of the wheel into the rotation of the wheel. Another object of the present invention is to provide an excellent robot apparatus and its control method capable of realizing traveling using wheels.

A further object of the present invention is to provide yaw rotation with respect to the wheels of the toes using a low degree of freedom per one leg of the multi-legged robot, and dynamically change the glide angle θ _G formed between the rolling direction of the wheels and the propulsion direction. It is another object of the present invention to provide an excellent robot apparatus, a control method therefor, and a passive wheel apparatus which can be passively changed to obtain desired propulsive force and moving speed.

The present invention has been made in consideration of the above problems, and is a robot apparatus including one or more movable legs,
A wheel mechanism attached to the tip of the movable leg and having a wheel supported to swing freely on the base surface of the sole;
An operation control means for controlling at least the operation of the movable leg,
The motion control means indirectly gives a glide angle θ _G formed between the rolling direction of the wheel and the traveling direction by giving the foot of the movable leg a motion that moves in a direction non-parallel to the traveling direction. It is a robot apparatus characterized by forming in.

  Legged mobile robots are highly adaptable to the ground, but are inferior to wheeled mobile robots in terms of movement speed and efficiency, so they have both the characteristics of both legged and wheeled mobile robots. It seems that the wheel hybrid type moving body is excellent. In consideration of the total weight of the airframe, it is preferable to use passive wheels instead of active wheels, but how to obtain propulsive force becomes a problem.

For example, the propulsive force by the passive wheel can be obtained by utilizing the anisotropy of the drag that the wheel rolling direction has a small friction coefficient and the axial direction has a large friction. In this case, the glide angle θ _G formed by the rolling direction of the passive wheel and the main propulsion direction of the robot must be formed with a small degree of freedom of the movable legs.

According to the present invention, the movement of the leg of the movable leg in a direction non-parallel to the traveling direction is given, thereby causing the wheel to swing by the frictional force between the wheel and the road surface. Thus, the glide angle θ _G formed by the rolling direction of the wheel and the traveling direction can be formed without using an indirect or active drive source. In this case, based on the anisotropy of the drag force that the rolling direction of the wheel has a small friction coefficient but the friction in the axial direction is large, the movement of the toe in a direction non-parallel to the traveling direction is performed. It is possible to obtain a propulsive force in the propulsion direction by converting it into a rotational motion.

Here, the motion control means moves the toe of the movable leg in a direction non-parallel to the traveling direction to give a swing motion to the wheel, thereby providing the propulsive force corresponding to the glide angle θ _G The reduction ratio can be obtained. A large propulsive force can be generated in the propulsion direction of the apparatus because the glide angle θ _G becomes a low speed when a large angle is applied. Conversely, by giving a small angle to the glide angle θ _G , the robot can be propelled at a high speed although it has a small propulsive force.

However, as a necessary condition for propulsion, the glide angle has a lower limit defined by the ratio of the friction coefficient in the rolling direction and the axial direction of the passive wheel, so the glide angle θ _G is changed according to the friction coefficient of the road surface. You may do it.

In addition, a limit mechanism for restricting the movable range of the swinging operation of the wheel may be provided so that the glide angle θ _G that is set only indirectly, that is, the speed reduction ratio range, falls within a desired range.

The limit mechanism can be configured by a limiter that is fixed at a predetermined fixed position and that abuts on the wheel that swings and restricts the movable range. For example, when a plurality of limiter fixed positions are provided, different movable ranges can be set according to the fixed positions, and the glide angle θ _G, that is, the reduction ratio can be adjusted. If you swing at a large angle, you will get a higher reduction ratio, and it will be easier to propel even on uneven road surfaces, while if you swing at a small angle, you will have a lower reduction ratio, and you can move on a smooth road surface at high speed. it can.

Or a limiter mechanism can be comprised with the elastic body which has a restoring force with respect to the swinging direction of the said wheel. In this case, the greater the force required to move the toe in a direction that is non-parallel to the traveling direction, the greater the restoring force of the elastic body, resulting in a larger glide angle θ _G. It can be regarded as a continuously variable transmission mechanism in which the reduction ratio automatically switches according to the state, and more efficient propulsion is possible.

  Further, since the wheel rotates indirectly, that is, passively based on the movement of the toe in the Y direction, the wheel itself has no braking mechanism. Therefore, a braking means for braking the propulsion obtained by the rotation of the wheel may be further provided.

  In this way, by mounting a passive wheel mechanism equipped with a swing caster on the toe of a walking machine, high-speed propulsion by the passive wheel becomes possible. Further, by configuring the passive wheel mechanism so as to be detachable with respect to the foot, it is not necessary to construct a system as a hybrid moving body in advance, and it is possible to add (that is, mount) according to the situation. Therefore, the wheel movement function can be easily added to the existing walking machine system. Moreover, since it replaces | exchanges for the leg-tip mechanism for a walk, or is mounted | worn with the form which covers it, if it removes, the performance of the original walking machine will not be impaired.

  In addition, the propulsive force obtained by using the passive wheel mechanism makes it possible to move faster than the maximum speed that can be obtained by legged movement. . Therefore, it can be said that the present invention is excellent in terms of entertainment properties.

  In the robot apparatus including at least one pair of left and right symmetrical movable legs, the motion control unit moves in a direction (Y direction) non-parallel to the traveling direction with respect to the toes of each movable leg. You may make it give the periodic motion used as left-right symmetry. In this way, the passive wheels attached to the left and right feet of the left and right movable legs configured symmetrically are caused to move in the Y direction so as to be symmetrical, thereby moving the robot in the traveling direction. The propulsive force can be obtained, and a linear movement faster than the legged movement can be realized.

  Further, when the left and right symmetrical movable legs are provided before and after the robot apparatus main body, the motion control means may provide a phase difference in the periodic motion of the toes between the front legs and the rear legs. .

When the leg position is in the vicinity of the extreme value, the swinging caster that passively moves performs a swinging motion and passively rotates until it is restrained by the opposite limiter. At this time, since the leg movement in the Y direction cannot generate a propulsive force, the propulsion speed decreases due to the rolling resistance of the wheels. In order to reduce such pulsation, a phase difference φ _fr is introduced into the front and rear legs. For example, when φ _fr = π / 2 or 3π / 2, the driving force exerted by the passive wheel is maximum when φ = 0 and π, and is minimum when φ = π / 2 or 3π / 2. Therefore, when the front leg loses propulsive force, if the rear leg propulsive force is maximized, the increase / decrease in the propulsive speed can be reduced and a steady moving speed can be realized.

  The robot apparatus may also include a steering movable leg with a steering wheel mechanism attached to the foot tip and a propulsion movable leg with the propulsion wheel mechanism attached to the foot tip. In such a case, the operation control means drives the movable leg for steering so that the rolling direction of the steering wheel mechanism coincides with the turning direction, and is applied to the foot of the movable leg for propulsion. By giving an operation of moving in a direction non-parallel to the traveling direction (Y direction), the movement of the toe in a direction non-parallel to the traveling direction is converted into a rotational motion of the wheel, and the propulsion direction Get the driving force against

  That is, when performing a turning motion, the passive wheel mechanism attached to the left and right front legs is used for steering, and the passive wheel mechanism attached to the left and right rear legs is used to generate the propulsive force. The steering movable leg is driven so that the rolling direction of the steering wheel mechanism coincides with the turning direction, and the toes of the left and right rear legs are caused to perform a symmetrical movement in the Y direction symmetrically in the left-right direction. Thus, based on the anisotropy of the drag force that the rolling direction of the wheel has a small friction coefficient but the friction in the axial direction is large, the motion in the Y direction is converted into the rotational motion of the propulsion passive wheel, and the propulsion direction ( Propulsive force in the direction of movement of the robot can be obtained. The propulsive force can be used to turn in the steered direction.

  Here, the operation control unit may swing the wheel by tilting the base surface of the sole so as to obtain a desired steering angle.

Although the swinging motion of the wheel cannot be directly manipulated, the trajectory that can be taken at the lowermost end of the wheel can be manipulated by tilting the base surface with respect to the floor surface. Assuming that the wheel is always in contact with the ground, the vertical drag from the floor surface acts in the positive Z direction. Therefore, the swinging operation is performed so that the ground contact point at the lowermost end of the wheel reaches the point where the distance between the floor surface and the base surface is the farthest, and this is stopped as a stable equilibrium point. The steering angle θ _str is obtained by projecting this stable equilibrium point onto the floor surface.

  ADVANTAGE OF THE INVENTION According to this invention, the robot apparatus which was excellent in the leg wheel hybrid type which had the characteristics of both leg type movement and wheel type | mold movement, its control method, and a passive wheel apparatus can be provided.

  In addition, according to the present invention, it is possible to provide an excellent robot apparatus, a control method therefor, and a passive wheel apparatus that can improve running performance by legs by adding passive wheels.

  In addition, according to the present invention, the disk-shaped passive wheel attached to the tip of the foot is used, the rolling direction of the wheel is rotated around the yaw, and the frictional force in the axial direction of the wheel is converted into the rotation of the wheel. It is possible to provide an excellent robot apparatus and its control method capable of obtaining power and realizing traveling using wheels.

In addition, according to the present invention, the rotation of the toe wheel is given to the wheel of the toe using a low degree of freedom per one leg of the multi-legged robot, and the glide angle θ _G formed by the rolling direction of the wheel and the propulsion direction is moved. It is possible to provide an excellent robot apparatus, a control method therefor, and a passive wheel apparatus capable of obtaining desired propulsive force and moving speed by changing the speed and the speed manually and indirectly.

The following can be mentioned as specific effects of the present invention.
(1) By adding a simple passive wheel mechanism to the legged walking machine, it is possible to move at high speed and with high efficiency.
(2) Since the passive wheel mechanism is detachable, it can be easily installed in a legged walking machine that has already been constructed.
(3) By removing the passive wheel mechanism from the tip of the foot, the original performance of the walking machine that corresponds to a discontinuous walking surface is not impaired.
(4) By introducing a passive joint, it can be applied even to a walking machine that does not have a yaw degree of freedom of the toe, and the glide angle θG formed by the rolling direction of the wheel and the propulsion direction can be dynamically changed. The desired driving force and moving speed can be obtained.
(5) The passive wheel mechanism according to the present invention is particularly effective in a multi-leg machine excluding two legs with a limited degree of freedom per leg, but of course, it is applied to a two-legged mobile robot. It is also possible.
(6) The passive wheel mechanism according to the present invention is basically a movement system based on the same principle as roller skates, and has high entertainment properties.
(7) With the control method according to the present invention, the user can interactively send a command in the propulsion direction and freely operate the robot apparatus.
(8) The passive wheel mechanism that can be additionally mounted is very simple and requires only a small number of parts, so that it can be designed and manufactured with high reliability and low cost.
(9) By applying the passive wheel mechanism according to the present invention, the walking type robot apparatus performs wheel type movement and is continuously grounded, so that the vertical movement of the center of gravity can be suppressed. In this case, for example, it is possible to improve riding comfort and to reduce disturbances such as an image captured by a camera mounted on the head.
(10) Since the four legs are always supporting legs, even if the passive wheel mechanism according to the present invention is applied, it is difficult to fall.
(11) The joint of the legged walking machine is designed to output a high torque at a low speed. Therefore, it can be said that the passive wheel mechanism according to the present invention is a movement system suitable for such joint output.
(12) Since passive wheels have little rolling friction, moving energy is not required when descending an inclined surface.

  Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The present invention relates to a multi-legged robot apparatus that can improve running performance with legs by adding passive wheels. The robot apparatus according to the present invention uses a disk-shaped passive wheel attached in advance to rotate the wheel in the rolling direction around the yaw, thereby propelling it by converting the axial frictional force of the wheel into the rotation of the wheel. It is possible to achieve power and travel using wheels.

In particular, the present invention assumes a joint arrangement as shown in FIG. 22 and provides yaw rotation with respect to the toe wheel using a small degree of freedom per leg, and rolling of the wheel that rotates passively. The desired propulsive force and moving speed can be obtained by dynamically and indirectly changing the glide angle θ _G formed by the direction and the propulsion direction.

  Moreover, in this invention, the passive wheel mechanism of a foot tip is made detachable, and a wheel type movement function is realizable by mounting | wearing a foot tip.

A. Passive Wheel Mechanism FIG. 1 shows the configuration of a passive wheel mechanism according to an embodiment of the present invention. The illustrated passive wheel mechanism 1 includes a base 11, a leg fixing portion 12 that is detachably attached to the tip of a leg portion of the robot on the upper surface of the base portion 11, and a yaw axis or passive rotation on the lower surface of the base portion 11. And a swing caster 14 rotatably attached around the passive rotation axis of the portion 13. Furthermore, a limiter 15 that restricts the movable range of the swing caster 14 around the yaw may be provided.

The swing caster 14 is supported by the passive rotation unit 13 so as to be rotatable about the yaw about the passive rotation axis with respect to the base unit 11. Here, the rotation angle around the yaw axis, that is, the passive rotation axis of the passive rotation unit 13 is set to θ _passive . Further, the wheel 16 is attached to the swing caster 14 with an offset with respect to the passive rotating shaft.

In the example shown in the figure, a frictional force is generated at the contact point of the wheel by the movement of the passive wheel (or the tip of the foot to which the passive wheel is attached) in the Y direction, and this swinging force causes the swing caster 14 to swing and passively rotate. The rotation angle θ _passive changes around the yaw axis of the portion 13. In this embodiment, the passive rotation axis is parallel to the Z axis of the absolute space Cartesian coordinate system, and θ _passive = θ _G , so that the wheel rolling direction and the propulsion direction ( Alternatively, the glide angle θ _G formed by the main traveling direction of the robot can be given. That is, the glide angle θ _G necessary for propulsion is indirectly generated by the movement in the Y direction.

  Then, based on the anisotropy of the drag force that the rolling direction of the wheel has a small friction coefficient but the friction is large in the axial direction, the motion in the Y direction of the foot to which the passive wheel is attached is converted into the rotational motion of the passive wheel 16. Is done.

Further, the glide angle θ _G corresponds to the gear reduction ratio, and if a larger angle is set by the glide angle θ _G , the glide angle θ _G becomes a low speed, so that a large propulsive force can be generated in the propulsion direction of the apparatus. Conversely, by giving a small angle to the glide angle θ _G , the robot can be propelled at a high speed although it has a small propulsive force. In the present embodiment, the glide angle θ _G corresponding to the reduction ratio can be indirectly set by the movement in the Y direction of the toe to which the passive wheel mechanism 1 is attached.

Further, as described above, the movable range around the yaw of the swing caster 14, that is, the glide angle θ _G is regulated by the limiter 15, so that the range of the reduction ratio set only indirectly is within the desired range. Can fit. For example, as shown in FIG. 2, it is possible to provide a plurality of fixed positions of the limiter 15 (three places in the illustrated example), set different movable ranges depending on the fixed positions, and adjust the reduction ratio. For example, as described in Non-Patent Document 6, if it is possible to swing at a large angle, the reduction ratio becomes higher, and it becomes easier to propel even on uneven road surfaces, while if it is allowed to swing at a small angle, the reduction is low. It becomes a ratio and can move on a smooth road surface at high speed.

In the example shown in FIG. 2, the limiter 15 is configured to limit the movable range of the glide angle θ _G in the passive wheel 16 by standing at any fixed position. The mechanism is not limited to this. For example, as shown in FIG. 3, the swinging motion of the passive wheel 16, that is, the rotation around the yaw, may be limited by using a spring. In this case, the greater the force required for the movement in the Y direction of the toe to which the passive wheel mechanism 1 is attached, the more the spring is stretched, resulting in a larger passive joint angle θ _Passive. It can be regarded as a continuously variable transmission mechanism in which the reduction ratio automatically switches according to the state, and more efficient propulsion is possible.

  Further, since the above-described passive wheel mechanism 1 performs a passive operation, the wheel 16 itself has no braking mechanism. Therefore, as shown in FIGS. 4 and 5, it is possible to perform a braking operation by adding a member having a large friction coefficient to the toe portion, for example, a rubber material, as in the case of the roller skate brake.

  In this way, by mounting the passive wheel mechanism 1 including the swing caster on the toes of the walking machine, high-speed propulsion using the passive wheels becomes possible. Further, by configuring the passive wheel mechanism 1 so as to be detachable from the foot, it is not necessary to construct a system as a hybrid mobile body in advance, and it can be added (that is, mounted) depending on the situation. Therefore, the wheel movement function can be easily added to the existing walking machine system. Moreover, since it replaces | exchanges for the leg-tip mechanism for a walk, or is mounted | worn with the form which covers it, if it removes, the performance of the original walking machine will not be impaired.

  Moreover, according to the propulsive force obtained using the passive wheel mechanism 1, it is possible to move faster than the maximum speed that can be obtained by the legged movement. Interesting. Therefore, it can be said that the present invention is excellent in terms of entertainment properties.

B. Method for Generating Motion by Legged Mobile Robot with Passive Wheel Mechanism In this section, a method for generating motion by a legged mobile robot using the above-described passive wheel mechanism will be described in detail. Here, a specific example applied to a four-legged walking robot having four movable legs as shown in FIG. 6 will be considered.

  The illustrated multi-legged walking robot includes a torso 22, a head 23, a left front foot 24A, a right front foot 24B, a left rear foot 24C, and a right rear foot 24D. Each of the legs 24 </ b> A to 24 </ b> D has a second unit 26 attached to the first unit 25 constituting a part or all of one side surface of the body 22 via the first joint portion 28, and the second unit 26. The third unit 27 includes two units attached via the second joint portion 29.

  The first joint portion 28 includes a first rotation shaft 31 having an axial direction parallel to the side surface of the body 22 and a second rotation shaft having an axial direction perpendicular to the side surface of the body 22. 32. The legs 24 </ b> A to 24 </ b> D can be rotated in a plane perpendicular to the side surface of the body 22 by the first rotation shaft 31, and are parallel to the side surface of the body 22 by the second rotation shaft 32. It can be rotated in the plane. The first rotation shaft 31 and the second rotation shaft 32 are accommodated in the first unit 25 and the second unit 26, respectively.

  The second joint portion 29 includes a third rotation shaft 33 housed inside the lower end of the second unit 26, and the axial direction thereof is directed in a direction parallel to the second rotation shaft 32. Therefore, the third unit 27 is rotatable in the front-rear direction of the second unit 26 with the third rotation shaft 33 as a fulcrum.

  Since the axial direction of the first rotating shaft 31 is arranged in a direction parallel to the side surface of the body 22, the cylindrical motor 30 can be easily accommodated in the first unit 25 as a driving source for driving the first rotating shaft 31. Can do. In addition, since the first rotating shaft 31 is configured as described above, the degree of freedom in the width direction of the body 22 is increased as compared with the prior art, and the inside of the body including the drive system for the first rotating shaft 31 is increased. Since an efficient layout configuration can be taken, the tooth width of each gear that communicates between the motor 30 and the first rotation shaft 31 can be increased. Therefore, high rigidity of the first joint portion 28 and high power performance can be realized.

  Hereinafter, for convenience, the left front leg, the left rear leg, the right rear leg, and the right front leg are referred to as the first leg, the second leg, the third leg, and the fourth leg in this order. Further, the first rotation axis, the second rotation axis, and the third rotation axis of each leg are referred to as J1, J2, and J3, respectively. FIG. 7 shows the movable range of the legs. FIG. 8 shows a reference posture and a torso coordinate system when the passive wheel mechanism 1 is mounted on a leg tip. In this example, it is assumed that only the rear leg has a brake mechanism.

  In this embodiment, the passive wheel 16 rotates indirectly or passively based on the movement of the tip of the foot in the Y direction, thereby moving in the traveling direction (in this embodiment, the X direction, that is, the front of the robot). Propulsion is gained. Since the movement of the toe in the Y direction naturally has a limited stroke width, it is possible to continuously generate a propulsive force by repeating periodic reciprocation in the positive and negative directions of the Y axis (that is, in the left-right direction). .

  FIG. 9 shows a processing procedure for generating the motion of the legged mobile robot using the passive wheel mechanism in the form of a flowchart.

  First, the traveling speed and traveling direction of the robot apparatus are set (step S1), and based on this, the leg motion such as the periodic function and the initial position is set (step S2).

  Here, it is checked whether or not the set leg motion is within the allowable range of the leg movable range (see FIG. 8) and the speed upper limit value (step S3). Here, when it deviates from an allowable range, it returns to step S2 and resets the exercise | movement of a leg.

  Next, the toe speed viewed from the absolute space Cartesian coordinate system is calculated (step S4), the frictional drag on the ground contact surface of the passive wheel 16 at the toe is calculated (step S5), and the center of gravity acceleration is calculated (step S6). . Then, the center-of-gravity acceleration is time-integrated to obtain the center-of-gravity speed (step S7), and it is determined whether the set traveling speed has been obtained (step S8). Here, if the set traveling speed cannot be obtained, the process returns to step S2 to reset the leg motion.

  If the leg motion set in step S2 can be obtained in this way, this is executed (step S9).

  Below, according to the motion production | generation procedure shown in FIG. 9, the case where a linear motion, a turning motion, and braking are performed with the multi-legged robot apparatus shown in FIG.

B-1. Linear motion First, the designer sets the traveling speed of the robot (the speed of the local coordinate origin as seen from the absolute coordinate system). Next, the leg motion is set as follows using the local coordinate system.

The leg position of the first leg is represented as (x1, y1, z1), and the reference posture is represented as (x1_offset, y1_offset, z1_offset). Let f (φ) be a continuous periodic function, and let φ be the phase (where 0 ≦ φ ≦ 2π). That is,

Here, t represents time [sec], and T ₀ represents period [sec].

  The leg position of the first leg (left front leg) is expressed by the following equation.

  In consideration of the symmetry of the left and right legs and keeping the posture of the robot apparatus main body constant, the leg position of the fourth leg (right front leg) is determined as follows.

Various periodic functions can be considered for f (φ). Since the passive joint angle is constrained by the limiter 15 and becomes a constant value (set to θ _{Passive_limit} ) at a number of phases, in order to keep the propulsion speed constant, f ( φ) is preferably used. Therefore, it is desirable to drive the leg using a periodic function f (φ) that generates a triangular wave shown below.

  In the above formula, A is an amplitude, which is appropriately determined in consideration of the movable range of the legs. By the way, if the equation (9) is determined, the Y-direction speed becomes discontinuous at φ = π / 2, 3π / 2, and therefore it is considered that an excessive load is applied to the actuator. When such a condition cannot be ignored mechanically, a sine wave may be used as the periodic function f (φ).

  FIG. 10 schematically shows the leg trajectory trajectory in the absolute coordinate system of the first leg and the fourth leg.

Now, when the leg position is in the vicinity of the extreme value, the swinging caster that passively moves performs a swinging motion and passively rotates until it is restrained by the limiter on the opposite side. At this time, since the leg movement in the Y direction cannot generate a propulsive force, the propulsion speed decreases due to the rolling resistance of the wheels. In order to reduce such pulsation, a phase difference φ _fr is introduced into the front and rear legs.

  The leg position of the second leg (left rear leg) is expressed by the following equation.

  Further, the leg position of the third leg (right rear leg) is expressed by the following equation.

The propulsive force is maximum when φ = 0 and π, and is minimum when φ = π / 2 or 3π / 2. Therefore, when the front leg loses propulsive force, if the rear leg propulsive force is maximized, the increase or decrease in the propulsive speed can be reduced. Therefore, by setting φ _fr = π / 2 or 3π / 2, a steady moving speed can be realized. FIG. 11 shows the leg trajectory trajectory in the absolute coordinate system when a phase difference is provided between the front and rear legs.

Now, since the leg tip position as seen from the body coordinate system is determined, the leg tip velocity V _leg can be obtained by time differentiation. When the passive wheel moves at a speed V _leg , the reaction force from the floor surface generated on the wheel is expressed by the following equation.

Here, F _t , F _n , μ _t , and μ _n are the passive wheel rolling direction friction force, the axial direction friction force, the rolling direction friction coefficient, and the axial direction friction coefficient, respectively. N is the vertical drag. Therefore, the reaction force acting on the robot is required from this relationship. Since the robot is propelled by this reaction force, the acceleration can be calculated. Then, the traveling speed can be obtained by first-order integration. At this time, if the traveling speed set in the first step is different, the process returns to the leg motion setting step again, and the leg motion setting parameters are repeatedly adjusted. Then, the motion is executed using a trajectory having a sufficiently small difference from the set traveling speed.

The moving speed can be changed by the amplitude A of the periodic motion f (φ) in the leg toe motion, the period T ₀ , and the limit angle of the passive caster (that is, the glide angle θ _G corresponding to the gear reduction ratio). is there. The simplest way to adjust the speed is to change only the period T ₀ . When an experiment was actually performed, a smooth speed change from a moving speed of 0 to approximately 1 [m / s] could be confirmed. Note that the maximum propulsion speed 1 [m / s] when the passive joint mechanism is used in the robot apparatus according to the present invention can achieve a movement that is approximately four times faster than walking.

The limit angle of the caster, that is, the maximum glide angle, acts as a kind of reducer. FIG. 12 illustrates a state where driving is performed at a constant speed in the pitch axis direction (that is, the Y direction) when viewed from the body coordinate system while keeping the glide angle θ _G constant. In this case, the velocity vector component V _x in the absolute coordinate system generated in the roll axis direction (X direction) is expressed by the following equation.

According to the above equation (19), it is understood that a high speed of movement as the glide angle theta _G is small. However, as a necessary condition for propulsion, the glide angle has a lower limit defined by the ratio of the friction coefficient in the rolling direction and the axial direction of the passive wheel, so the glide angle θ _G is changed according to the friction coefficient of the road surface. It is necessary.

  The position command value for each joint is obtained by calculating the rotation angle of each joint axis J1, J2, J3 by inverse kinematics calculation, and then the leg is driven by the local position control system. Here, it can be seen from the joint arrangement that the Y-direction position of the foot tip to which the passive wheel mechanism is attached is mainly determined by the J1 angle. Accordingly, it is possible to approximately use the value of Y as the command value for J1 without using the inverse kinematics operation.

  Moreover, although the control method by position control using inverse kinematics has been described here, speed control, force control, a control method considering dynamics, and the like are also conceivable.

B-2. In the case of the straight movement described above, by causing the passive wheels 16 attached to the tips of the left and right movable legs configured symmetrically to cause a periodic movement in the Y direction so as to be symmetrical. Therefore, it is possible to obtain a propulsive force in the traveling direction of the robot and to realize a straight movement. In contrast, in this section, the case of steady turning along an arc having a certain turning radius will be considered.

  In the case of the turning motion, it can be realized by appropriately changing the offset value of the reference leg position shown in the above formulas (3) to (8) and formulas (11) to (16). For example, when turning to the left, the reference leg position of each of the four legs is set to the position shown in FIG. 13, and the turning movement can be realized, for example, by oscillating only the right leg. At this time, a small turning radius such as a pivot turn can be realized by using the brake of the toe of the left rear leg as a turning center point.

  However, such turning by changing the leg position takes time to change the leg position when an arbitrary turning radius is commanded. Further, depending on the passive joint angle, the behavior at the time of leg position transition is not constant, and it is considered not suitable when the user interactively changes the propulsion direction, for example.

  Therefore, the present inventors propose a method for sharing functions between the front legs and the rear legs. One of the legs is used for steering and the other is used to generate propulsion.

  When performing the turning motion, the passive wheel mechanism attached to the left and right front legs is used for steering, and the passive wheel mechanism attached to the left and right rear legs is used for generating the propulsive force. That is, the steering movable leg is driven so that the rolling direction of the steering wheel mechanism coincides with the turning direction, and the toe of the left and right rear legs is moved symmetrically in the Y direction. As a result, the movement in the Y direction is converted into the rotational movement of the passive wheel based on the drag anisotropy that the rolling direction of the wheel has a small friction coefficient but the friction in the axial direction is large. Propulsive force in the direction of movement of the robot can be obtained.

  Of course, instead of using the left and right front legs for steering and the left and right rear legs for propulsion, the left and right front legs may be used for propulsion and the left and right rear legs for steering. By using the left and right legs with driving force for propulsion, a larger propulsive force can be obtained and high-speed movement can be realized.

  Since it is sufficient to use a method similar to the straight-ahead operation for generating the propulsive force, a steering method using a passive joint axis will be described in detail below.

When the swinging caster cannot be rotated directly around the passive joint axis, but the base can be tilted in the roll and pitch directions (ie, the base can be tilted with respect to the floor). As shown in FIG. 14, the trajectory that can be taken by the lowermost end of the passive wheel is represented by a circle on the inclined surface with the passive rotation axis as the center. Assuming that the wheel is always in contact with the ground, the vertical drag from the floor surface acts in the positive Z direction. Therefore, the passive joint rotates, and the intersection of the maximum inclination line direction of the base plane and the passive wheel locus circle becomes a stable equilibrium point and stops there. In other words, the swinging operation is performed so that the ground contact point at the lowermost end of the wheel reaches the point where the distance between the floor surface and the base surface is farthest, and the arrival point becomes a stable equilibrium point. If this stable equilibrium point is projected onto the floor surface, the steering angle θ _str can be obtained. Therefore, if the base portion can be tilted in the roll and pitch directions (that is, the base portion is tilted with respect to the floor surface), the steering angle θ _str can be continuously changed.

Hereinafter, the relationship between the (roll, pitch) of the base portion and the steering angle θ _str will be described specifically using mathematical expressions. The coordinate system is taken on the floor surface, the roll direction and pitch direction of the base portion 11 are θ _Roll and θ _Pitch , the center Z coordinate of the passive rotation is Z ₀ , and the turning radius of the passive wheel 16 is R. The base portion 11 rotates in the order of θ _Pitch and θ _Roll . In the following derivation, sin θ _Pitch ≠ 0. When sin θ _Pitch = 0, it is considered separately qualitatively.

  The position of the lower end of the passive wheel is determined as follows:

At this time, the trajectory drawn by the lower end of the passive wheel is expressed as follows using θ _Passive as a parameter.

Since the stable equilibrium point is a point at which P _z becomes the maximum value, θ _passive that maximizes the function g shown in the following equation may be obtained.

  By solving the above equation, the following equation can be obtained.

At this time, the effective steering angle θ _{str with} respect to the floor surface is obtained by the following equation.

More specifically, the steering angle θ _str is expressed by the following equation in consideration of the angle formed with the traveling direction.

Thus, (θ _Roll , θ _Pitch ) for obtaining the desired θ _str is obtained.

  The relationship described above can also be applied to the reference posture as shown in FIG. Here, as an example, the position where the swinging caster for passively moving the front leg is changed, the front leg performs steering, and the rear leg generates propulsive force. The leg position / posture shown in FIG. In this case, the front legs have a reduced degree of freedom, but when the roll and pitch are changed, the displacement of the passive wheel ground contact position is very small, and smooth steering can be expected. The rear leg generates a propulsive force in the same leg trajectory as the straight movement described above.

First, a qualitative explanation will be given based on intuition. With respect to the front leg, in the case of the leg position as shown in FIG. 15, the posture (Roll, Pitch) of the base portion can be changed using the joint rotation axes J2 and J3, and as described above, the rudder is steered. The taking angle θ _str can be changed. In this way, steering can be performed with the front legs of the quadruped robot shown in FIG. 5, and propulsive force can be generated with the rear legs.

For example, when only the joint rotation axis J2 is tilted in the positive direction (corresponding to the case where sin θ _Pitch = 0), the passive rotation axis of the swing caster is tilted in the roll positive direction. Because the robot's own weight causes the Z-direction vertical floor reaction force to always _{act on} the swing caster, the swing caster rotates until it is restrained by the positive limit (θ _{Passive_limit +} ) (see Fig. 16). .

When the joint rotation axis J3 is tilted and only the pitch angle θ _Pitch is changed, the passive joint angle becomes a stable equilibrium point at a point where it becomes zero. Therefore, it can be qualitatively understood that the passive joint angle can be smoothly changed from zero to the limit value by combining (Roll, Pitch).

Next, numerical description will be given using Equation (26). Since the steering angle θ _str is determined by two variables from the equation (26), (θ _Roll , θ _Pitch ) cannot be uniquely determined when the steering angle θ _str is given. Therefore, the relationship between the roll angle θ _Roll and the steering angle θ _str was determined using the pitch angle θ _Pitch as a parameter (see FIG. 17). This is shown in FIG. When the steering angle θ _str is determined according to the above equation (26), the passive joint angle limit mechanism is not necessarily required. In FIG. 18, it is shown in a range from zero to 90 [deg] in consideration of symmetry.

If the roll angle θ _Roll is mainly used for steering, the pitch angle θ _Pitch can be regarded as a conversion gain to the steering angle θ _str . That is, if the pitch angle θ _Pitch is set small, a large steering angle θ _str can be obtained with a smaller roll angle θ _Roll . Conversely, if the pitch angle θ _Pitch is set to be large, a small steering angle θ _str is converted with respect to a change in the roll angle θ _Roll .

Actually, as shown in FIG. 7, the roll angle θ _Roll has a small movable range of 15 [deg] inside the fuselage, so that the steering angle θ _str is greatly expanded by reducing the pitch angle θ _Pitch. be able to. Further, if the pitch angle θ _Pitch is increased, the stability of the steering angle θ _str can be improved. In other words, since the steering angle θ _str becomes dull with respect to the change in the roll angle θ _Roll , even if a disturbance is applied and the roll angle θ _Roll is disturbed, the change in the steering angle θ _str itself is small. Therefore, the steering is stable. Such characteristics can of course be applied to straightness.

In addition, the steering angle θ _str is about 30 [deg] in the case of steering in a normal automobile. Therefore, the steering angle θ _str = roll angle θ _Roll = 15 [deg]. When the pitch angle θ _Pitch = 42 [deg] is set so as to take 30 [deg], the relationship between the roll angle θ _Roll and the steering angle θ _str is as shown in FIG. Even if it approximates linear in this range, there is no problem. Therefore, it can be seen that there is no inferiority even when the roll angle θ _Roll is regarded as a normal automobile steering.

In this example, the pitch angle θ _Pitch is fixed and the steering is performed by operating the roll angle θ _Roll . However, according to the above equation (26), the roll angle θ _Roll is fixed, and the pitch angle is used instead. θ _Pitch may also be treated as a variable. In addition, when the above equation (26) is derived, the base portion is rotated in the order of the pitch angle θ _Pitch and the roll angle θ _Roll .

  By the way, when performing straight ahead, as explained in the section B-1, the propulsive force of the four legs was used by generating a periodic vibration motion in the Y direction using the joint rotation axis J2 also for the front legs. It goes without saying that you can exercise. Therefore, propulsion in which the inclinations of the joint rotation axes J2 and J3 for steering and the linear movement are superimposed is also possible.

When the method described in this section was implemented in a quadruped robot, it was confirmed that it smoothly turns on the flooring floor with a radius of about 0.4 [m].

B-3. As for the braking and braking operation, a method using a rubber material attached to the toe portion as described above can be cited. In addition, the steering angle θ _str is tilted symmetrically as in the case of Bogen (sliding method that controls the speed and direction by holding the ski in the shape of a figure and putting the force inside the board). A method is also conceivable. As described above, it is shown that the passive joint angle θ _Passive corresponding to the glide angle θ _G can be changed by using the two joint rotation axes J2 and J3. The braking operation can be performed by adding an angle of a toe out (a state in which the front is open with respect to the traveling direction).

  The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention.

  The gist of the present invention is not necessarily limited to a product called a “robot”. That is, if it is a mechanical device or other general mobile device that performs a movement resembling human movement using electrical or magnetic action, it is a product belonging to another industrial field such as a toy. Even if it exists, this invention can be applied similarly.

  In the present specification, the present invention has been described mainly with respect to an embodiment in which the present invention is applied to a multi-leg machine excluding two legs with a limited degree of freedom per leg, such as the quadruped robot shown in FIG. However, it is of course possible to apply the present invention to a two-legged mobile robot.

  In short, the present invention has been disclosed in the form of exemplification, and the description of the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims should be taken into consideration.

FIG. 1 is a diagram showing a configuration of a passive wheel mechanism according to an embodiment of the present invention. FIG. 2 is a diagram showing a state where a plurality of fixing positions of the limiter 15 are provided. FIG. 3 is a view showing a limit mechanism configured using a spring. FIG. 4 is a diagram illustrating a state in which the braking mechanism is configured using a member having a large friction coefficient at the toe portion of the passive wheel mechanism. FIG. 5 is a diagram illustrating a state in which the braking mechanism is configured using a member having a large friction coefficient at the toe portion of the passive wheel mechanism. FIG. 6 is a diagram showing a configuration example of a quadruped legged mobile robot to which the present invention is applied. FIG. 7 is a diagram showing a movable range of the legs of the robot apparatus shown in FIG. FIG. 8 is a diagram showing a reference posture and a torso coordinate system when the passive wheel mechanism 1 is attached to the foot of a leg. FIG. 9 is a flowchart showing a processing procedure for generating the motion of the legged mobile robot using the passive wheel mechanism. FIG. 10 is a diagram schematically showing the trajectory of the leg in the absolute coordinate system of the first leg and the fourth leg of the robot apparatus shown in FIG. FIG. 11 is a diagram showing leg trajectories in the absolute coordinate system when a phase difference is provided between the front and rear legs. FIG. 12 is a diagram illustrating a state in which driving is performed at a constant speed in the pitch axis direction (that is, the Y direction) as viewed from the body coordinate system while keeping the glide angle constant. FIG. 13 is a diagram illustrating a state in which the turning motion is performed by appropriately changing the offset value of the reference leg position of the quadruped robot illustrated in FIG. 6. FIG. 14 is a diagram showing a trajectory that can be taken by the lowermost end of the passive wheel represented by a circle on the inclined surface with the passive rotation axis as the center. FIG. 15 is a diagram showing the leg position / posture reference when the quadruped robot shown in FIG. 5 performs the turning motion. FIG. 16 is a diagram showing how the swing caster rotates until it is restrained by the positive limit (θ _{Passive_limit +} ) because the Z-direction vertical floor reaction force is always acting on the swing caster due to the weight of the robot. It is. FIG. 17 is a diagram illustrating a state where θ _Pitch is used as a parameter. FIG. 18 is a diagram showing the relationship between the roll angle θ _Roll and the steering angle θ _str . Figure 19 is a roll angle theta _Roll and steering angle in the case of setting the pitch angle θ _Pitch = 42 [deg] to take a roll angle θ _Roll = 15 [deg] steering in square θ _str = 30 [deg] It is the figure which showed the relationship of (theta) _str . FIG. 20 is a diagram schematically showing the degree of freedom configuration of the roller walker. FIG. 21 is a diagram schematically illustrating the configuration of the degree of freedom of the roller walker. FIG. 22 is a diagram illustrating an example of joint arrangement of a multi-legged robot.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Passive wheel mechanism 11 ... Base part 12 ... Leg fixing part 13 ... Passive rotating part 14 ... Swing caster 15 ... Limiter 16 ... Passive wheel

Claims (24)

A robot apparatus having one or more movable legs,
A wheel mechanism attached to the tip of the movable leg and having a wheel supported to swing freely on the base surface of the sole;
An operation control means for controlling at least the operation of the movable leg,
The motion control means causes the tip of the movable leg to move in a direction non-parallel to the traveling direction, thereby causing the wheel to swing by the frictional force between the wheel and the road surface. Indirectly forming a glide angle θ _G formed by the rolling direction of the wheel and the traveling direction, based on the anisotropy of the drag force that the rolling direction of the wheel has a small coefficient of friction but the friction in the axial direction is large. , The movement of the toes in a direction non-parallel to the traveling direction is converted into the rotational movement of the wheels to obtain a propulsive force for the propulsion direction.
A robot apparatus characterized by that. The operation control means, by which the movable leg of the foot is moved relative to the traveling direction to a direction non-parallel impart oscillating operation to the wheel, the reduction ratio of the driving force corresponding to the glide angle theta _G Get the
The robot apparatus according to claim 1. The operation control means changes the glide angle θ _G according to the friction coefficient of the traveling road surface.
The robot apparatus according to claim 2. A limit mechanism that regulates the movable range of the swinging operation of the wheel, and the range of the reduction ratio that is set only indirectly falls within a desired range.
The robot apparatus according to claim 1. The limit mechanism is fixed at a predetermined fixed position and is configured by a limiter that abuts on the wheel that swings and regulates a movable range.
The robot apparatus according to claim 4, wherein: The limiter mechanism is composed of an elastic body having a restoring force with respect to the swinging direction of the wheel.
The robot apparatus according to claim 4, wherein: Braking means for braking the propulsion obtained by the rotation of the wheel;
The robot apparatus according to claim 1. The wheel mechanism is detachably attached to the tip of the movable leg.
The robot apparatus according to claim 1. Comprising at least one pair of left and right symmetric movable legs, and the wheel mechanism is mounted on the tip of each movable leg;
The motion control means gives a symmetrical symmetrical movement that moves in a direction non-parallel to the traveling direction with respect to the toe of each of the left and right symmetrical movable legs,
The robot apparatus according to claim 1. The robot apparatus main body is provided with left and right symmetrical movable legs, and the wheel mechanism is attached to the tip of each movable leg,
The motion control means provides a phase difference in the periodic motion of the toes between the front legs and the rear legs.
The robot apparatus according to claim 9. A steering leg with a steering wheel mechanism attached to the toe and a propulsion leg with a propulsion wheel mechanism attached to the toe,
The operation control means drives the movable leg for steering so that the rolling direction of the steering wheel mechanism coincides with the turning direction, and at the tip of the movable leg for propulsion with respect to the traveling direction. The movement of the toes in a direction non-parallel to the traveling direction is converted into a rotational movement of the wheel to give a propulsive force in the propulsion direction by giving an action of moving in a non-parallel direction.
The robot apparatus according to claim 1. The operation control means tilts the base surface of the sole to swing the wheel so that a desired steering angle is obtained.
The robot apparatus according to claim 11. A control method of a robot apparatus comprising one or more movable legs, and equipped with a wheel mechanism having a wheel supported so as to swing freely on a base surface of a sole of the movable leg,
Giving the foot of the movable leg an action of moving in a direction non-parallel to the traveling direction;
Indirectly forming a glide angle θ _G formed by the rolling direction of the wheel and the traveling direction by a swinging action on the wheel generated by the frictional force between the wheel and the road surface accompanying the movement of a foot tip;
Converting the movement of the toes in a direction non-parallel to the traveling direction to rotational movement of the wheels to obtain a propulsive force in the propulsion direction;
A method for controlling a robot apparatus, comprising: In the step of indirectly form a glide angle theta _G above, to obtain a reduction ratio of the driving force corresponding to the glide angle theta _G,
The robot apparatus control method according to claim 13. In the step of indirectly form a glide angle theta _G of the changes the glide angle theta _G depending on the friction coefficient of the road surface,
The method for controlling a robotic device according to claim 14. The robot apparatus includes at least one pair of left and right symmetrical movable legs, and the wheel mechanism is attached to the tip of each movable leg,
In the step of applying motion to the toes of the movable legs, the symmetrically moving periodic legs that move in a direction non-parallel to the traveling direction with respect to the toes of the left and right symmetrical movable legs. Give exercise,
The robot apparatus control method according to claim 13. The robot apparatus main body is provided with left and right symmetrical movable legs, and the wheel mechanism is attached to the tip of each movable leg,
In the step of giving motion to the toes of the movable legs, a phase difference is provided in the periodic movement of the toes between the front legs and the rear legs.
The method of controlling a robot apparatus according to claim 16. A steering leg with a steering wheel mechanism attached to the toe and a propulsion leg with a propulsion wheel mechanism attached to the toe,
The step of giving an action to the tip of the movable leg includes a step of driving the movable leg for steering so that a rolling direction of the steering wheel mechanism coincides with a turning direction, and a movable part for propulsion. Providing a movement of the leg toes in a direction non-parallel to the traveling direction.
The robot apparatus control method according to claim 13. The step of driving the movable leg for steering described above tilts the base surface of the sole and swings the wheel so that a desired steering angle can be obtained.
The method for controlling a robotic device according to claim 18. A passive wheel device that is applied to a robot apparatus that includes a plurality of movable legs and performs a legged movement operation, and that generates a propulsive force by generating a passive rotational action according to the movement of the movable legs,
A base part;
A leg fixing portion that is detachably attached to the tip of the movable leg on the upper surface of the base portion;
A swing caster supported on the lower surface of the base portion so as to be rotatable about the passive rotation axis around the yaw, and having wheels attached thereto with an offset relative to the passive rotation axis;
A passive wheel device comprising: Further comprising a limit mechanism for regulating a movable range of the swinging motion of the wheel,
21. The passive wheel device according to claim 20, wherein: The limit mechanism is fixed at a predetermined fixed position and is configured by a limiter that abuts on the wheel that swings and regulates a movable range.
The passive wheel device according to claim 21, wherein: The limiter mechanism is composed of an elastic body having a restoring force with respect to the swinging direction of the wheel.
The passive wheel device according to claim 21, wherein: Braking means for braking the propulsion obtained by the rotation of the wheel;
21. The passive wheel device according to claim 20, wherein:

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