JP2004167663A - Leg type moving robot and foot mechanism of leg type moving robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leg type moving robot which suppresses the change of an effective surface for drag generation accompanied by the change of a foot shape due to ZMP movement. <P>SOLUTION: A main body 21 attached with an ankle connection part 41 to be connected with an ankle is bonded with a bottom soft part 22 by, for example, adhesion. The main body 21 is not deformed by torque generated in a lower limb and a reactive force from a transfer surface 19 and has hardness to secure support moment. The soft part 22 has both the function of the bottom soft part 22 and the function of a contact part of the transfer surface 19. Ground contact distribution relative to the transfer surface 19 is adjusted by the suitable selection of the shape of the main body 21. The outer edge of the foot soft part 22 to contact with the transfer surface 19 is formed with R and unnecessary hooking to the transfer surface 19 is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a legged mobile robot that walks with at least a plurality of movable legs, and particularly to a legged mobile robot that moves on various road surfaces (moving surfaces) with the movable legs. The invention also relates to a foot mechanism of a legged mobile robot that walks on various moving surfaces with at least a plurality of movable legs.
[0002]
[Prior art]
A mechanical device that performs a motion resembling a human motion using an electric or magnetic action is called a “robot”. It is said that the robot is derived from the Slavic word "ROBOTA (slave machine)". In Japan, robots began to spread from the late 1960's, but most of them were industrial robots (industrial robots) such as manipulators and transfer robots for the purpose of automation and unmanned production work in factories. Met.
[0003]
A stationary robot, such as an arm-type robot, which is implanted and used in a specific place, operates only in a fixed and local work space such as assembling and sorting parts. On the other hand, the mobile robot has a work space that is not limited, and can freely move on a predetermined route or on a non-route to perform a predetermined or arbitrary human work, or perform a human or dog operation. Alternatively, various services that replace other living things can be provided. Among them, legged mobile robots are unstable and pose control and walking control are more difficult than crawler type robots and tire type robots.However, climbing up and down stairs and ladders, climbing over obstacles, and distinguishing between terrain and rough terrain are difficult. It is excellent in that flexible walking and running motions can be realized regardless of the type.
[0004]
Recently, it has imitated the pet's robot that imitated the body mechanism and behavior of a four-legged animal such as a dog, cat, and bear, or the animal's body mechanism and motion that bipedally walks such as a human. Research and development on the structure of a legged mobile robot such as a "humanoid" or "humanoid" robot and its stable walking control have been advanced, and expectations for its practical use have been increased.
[0005]
Most of the human working space and living space are formed in accordance with the human body mechanism and behavior style of standing upright with two feet. In other words, there are too many barriers in the living space of human beings for the current mechanical system using wheels or other driving devices to move. In order for a mechanical system, that is, a robot to support or substitute for various human tasks and penetrate deeply into a human living space, it is preferable that the movable range of the robot is almost the same as that of a human. This is the reason why practical use of the legged mobile robot is greatly expected. It can be said that having a humanoid form is indispensable for a robot to enhance affinity with a human living environment.
[0006]
Many techniques related to posture control and stable walking have been proposed for a robot of the type that performs legged movement by bipedal walking. Stable “walking” here can be defined as “moving using the legs without falling over”. The posture stability control of the robot is very important in avoiding the falling of the robot. This is because falling means that the robot interrupts the work being performed, and considerable effort and time is spent in getting up from the falling state and resuming the work. In addition, above all, there is a risk that the fall may cause fatal damage to the robot body itself or the object on the other side that collides with the fallen robot. Therefore, in designing and developing a legged mobile robot, posture stabilization control during walking and other legged work and prevention of falling during walking are one of the most important technical issues.
[0007]
At the time of walking, gravity, inertia force, and these moments act on the road surface from the walking system due to gravity and acceleration generated by the walking motion. According to the so-called "Dalambert principle", they balance the floor reaction force and the floor reaction force moment as a reaction from the road surface to the walking system. As a consequence of the mechanical inference, there is a point where the pitch and roll axis moments are zero on or inside the supporting polygon formed by the sole and the road surface, that is, "ZMP (Zero Moment Point)".
[0008]
FIG. 34 shows the pitch and roll axes and the yaw axis described later. That is, the O-XYZ coordinate system shown in FIG. 34 shows the roll, pitch, and yaw axes in absolute coordinates. In particular, the yaw axis is a left-right rotation axis generated around the body of the robot standing perpendicular to the moving surface.
[0009]
Many proposals relating to posture stability control of a legged mobile robot and fall prevention during walking use this ZMP as a criterion for determining walking stability (for example, JP-A-2001-157773). The bipedal walking pattern generation based on the ZMP standard has an advantage that a sole landing point can be set in advance, and the kinematic constraint condition of the toe according to the road surface shape can be easily considered. In addition, using ZMP as a stability determination criterion means that a trajectory, not a force, is treated as a target value in motion control, so that technical feasibility is increased. The concept of ZMP and the application of ZMP to the stability discrimination standard for walking robots are described in "LEGGED LOCOMMOTION ROBOTS" by Miomir Vukobratovic (Ichiro Kato, "Walking Robots and Artificial Feet" (Nikkan Kogyo Shimbun)). It is described in.
[0010]
In addition, the stability and controllability of the legged mobile robot during legged work are affected not only by the movement patterns of the lower limbs, but also by the conditions of the moving surface such as the ground, floor, and road where legged work such as walking is performed. ing. This is because, as long as the foot is in contact with the moving surface, it is constantly receiving a reaction force from the moving surface. For this reason, the structure of the foot contacting the moving surface and the ground is extremely important for stability and controllability during legged work in the legged mobile robot.
[0011]
A number of proposals have been made on the structure of the foot mechanism so far, to reduce the impact received from the moving surface when the free leg lands, and to reduce the slip on the moving surface. Was most.
[0012]
[Patent Document 1]
JP-A-2001-157973
[0013]
[Problems to be solved by the invention]
However, for example, in the walking of the legged mobile robot, as shown in FIG. 35, when the ZMP comes on the foot 401, the load of the legged mobile robot is applied to the ZMP, and the foot 401 is placed on the road surface (moving surface). It may bend in the arrow direction U opposite to the direction 400, causing a change in shape. At this time, the contact area between the foot 401 and the road surface 400 is reduced, and the resistance to the moment about the yaw axis, which is the axis of left and right rotation around the body of the robot, is weakened. In addition, due to the change in the shape, the shape of the contact surface between the sole of the foot 401 and the moving surface 400 also changes, and this change causes a change in the dynamic characteristics of the legged mobile robot, thereby making the posture of the robot unstable. Can be the cause.
[0014]
Here, a concept named “drag generation effective surface” will be introduced in the present specification, and the above-mentioned design will be further described. The drag generation effective surface means, for example, when the contact surface between the foot 401 and the moving surface 400 is one surface. As shown in FIG. 36, when the foot 401 and the moving surface 400 are point grounded by a plurality of (four in FIG. 36) road grounding portions 402 provided on the foot 401, the adjacent road grounding portions A plane 403 is surrounded by a side connecting two points 402. As shown in FIG. 37, when the ground contact portion of the foot 401 is the frame-shaped road ground frame 404, the surface surrounded by the side of the road ground frame 404 means the effect generation execution surface 405. That is, the “drag generation effective surface” means a region connecting points receiving a drag from the road surface with respect to a moment about the yaw axis generated in the legged mobile robot.
[0015]
When the leg is deformed by the movement of the ZMP during walking of the legged mobile robot and the area of the effective drag generating surface is reduced, the legged mobile robot becomes weak against the moment about the yaw axis generated by the operation of the legged mobile robot, This causes the mobile robot to become unstable in posture and cause spin motion. In addition, the deformation of the drag generating effective surface causes an unexpected change in the behavior of the legged mobile robot, which causes the posture of the legged mobile robot to become unstable.
[0016]
Therefore, what is important on the bottom surface of the foot of the legged mobile robot is to not only adjust the surface pressure on the ground contact surface statically or dynamically as described later, but also to change not only the simple pressure value but also its change. And the distribution, and the friction is likewise statically or dynamically adjusted.
[0017]
However, the above is a problem mainly limited to a flat moving surface or a gentle continuous surface, but in consideration of an actual moving surface, in addition to a continuous surface such as undulations, irregularities, steps, etc. It should also be noted that discontinuous surfaces are possible. As shown in FIG. 38, for example, when there is a step on the moving surface 406 (upper moving surface 406U, lower moving surface 406D), if the foot 401 comes into contact with a corner of the cliff 406C forming the step. The foot 401 is in an unstable state with its ground portion as a fulcrum. There is no reaction force, an impact acts on the lower side, and if control is made to apply force to the toes to endure it, the impact already acts on the upper side at that time. By repeating this, an oscillation state is set. Then, it becomes impossible to generate a supporting moment at the ground contacting portion, and the behavior thereof is exactly a non-linear system and extremely difficult to control.
[0018]
In addition, in the robot aiming to perform a fast movement by reducing the weight, when the carpet 407 having a long hair is unable to be completely crushed by the foot 401 as shown in FIG. A sufficient supporting moment cannot be secured. Because the long bristle feet 407 of the carpet cannot be squashed, they slip on the carpet, the position of the foot 401 cannot be kept horizontal, or the friction characteristics change. In other words, on a fragile and slippery surface, such as a carpet 407 with long hairs, which cannot secure a supporting moment for a robot having a light weight, there is a possibility that the ground surface of the foot portion 401 may slip more than necessary. There is a possibility that the movement stability of the legged moving body itself is significantly impaired. In addition, the movement locus tends to be disturbed, so that it is necessary to perform correction control and reset a movement plan. Of course, even when the material of the moving surface itself has a remarkably low frictional force and is easy to slide irrespective of the weight of the robot, a supporting moment cannot be secured and the same occurs.
[0019]
Further, as shown in FIG. 40, in a moving surface 408 having a large friction or a moving surface where the surface is soft and the surface is caught, the surface pressure due to the effect of the shape of the sole contact surface of the foot portion 401, or particularly the surface If the friction in the direction is extremely increased, an overturning moment is generated due to an inertial force or the like. Therefore, it is necessary to adjust the friction characteristics of the ground contact portion.
[0020]
By the way, as shown in FIG. 41, where there is a step (a cliff 406C between the upper moving surface 406U and the lower moving surface 406D) on the moving surface 406, in addition to the supporting moment shown in FIG. There are even serious problems. When the condition of the shape near the step portion (cliff portion 406C) or the uneven portion is bad, or when the friction is extremely small, the problem of the foot portion 401 sliding down in the arrow 409 direction cannot be ignored. Since the behavior is extremely fast as compared with the control cycle or the like, there is a risk that it is not possible to cope sufficiently.
[0021]
Aside from this sliding down, a similar problem occurs when the obstacle 411 is stepped on the moving surface 410 as shown in FIG. At present, unless a robot is programmed to take an avoidance action on an object determined to be an obstacle, the robot cannot recognize whether it is dangerous unless it touches the object. Can not. Therefore, as shown in FIG. 42, it is recognized whether or not it is dangerous to step on the obstacle 411 that has a circular cross section or a cylindrical shape and rolls, without stepping on the foot 401. It may not be possible. When the so-called arch, which is the center of the foot 401, comes into contact with the obstacle 411, a portion around the arch does not properly touch the moving surface 410, and the foot 401 does not apply force to the moving surface 410. become. Thereby, not only the supporting moment but also the friction is extremely reduced. In addition, when the obstacle 411 rotates in the direction of the arrow 412 and starts moving, the state changes every moment, and the control becomes extremely difficult. And there is a possibility of falling. Again, the need for countermeasures is high.
[0022]
By the way, when designing the sole of the foot, in consideration of protection of the moving surface, securing of frictional force, and the like, it is usually considered that a material such as rubber is selected from an image of shoes or the like. Many robots in the research area have selected rubber. In consideration of the properties of rubber, it is a sufficiently conceivable method to pursue softness.
[0023]
However, as shown in FIG. 43, in the case where a rubber material 414 having a thick bottom and a soft bottom is selected and fixed to the base 413, it is considered that the above-described various problems can be solved, but a new problem occurs. The force (inertial force or the like) in the direction of the moving surface 415 can occur even in an ordinary walk, and when approaching any obstacle, the same thing can occur by receiving a force from other than the target leg.
[0024]
That is, if the frictional force around the outer edge is extremely high or rises, and the material itself cannot support it, deformation as shown in FIG. 43 occurs. This is because, in addition to the absolute frictional force between the rubber material and the moving surface, a time-series frictional force is generated due to the elasticity of the rubber material. It suffices if the manner of deformation of the rubber can be appropriately controlled and adjusted so that the frictional force does not change abruptly. However, if the adjustment and control cannot be performed, the frictional force changes abruptly and the moving surface contact portion 414a of the rubber material becomes a stick. Causes chatter vibration such as slip. In addition, when the frictional force further increases, a falling moment is generated or a so-called snagging occurs, the moment acts in a direction that impairs stability. For this reason, it should be considered that the design, such as the structure, method, material selection, and the like of this part is not easy, and that a thorough study is required.
[0025]
As described above, in order to realize a plantar surface that can be adapted to a wide variety of moving surfaces, such as a continuous surface, a discontinuous surface, a rigid body surface, and a viscoelastic surface,
1) Shape around the grounding part
2) Shape change around the ground contact
3) Friction around the contact area and its distribution
4) Friction around the ground contact area and its distribution, each change
Etc. need to be set and adjusted appropriately. Thus, it is considered that the performance as a mobile machine can be dramatically improved.
[0026]
Although it cannot be said that optimal characteristics can be comprehensively obtained in all planes, it is certain that the range of movable terrain can be expanded by appropriately selecting these characteristics.
[0027]
An object of the present invention is to solve the above-described problems, and more specifically, to suppress a change in a drag-generating effective surface accompanying a change in a foot shape due to a ZMP movement of a legged mobile robot. And a foot mechanism of the legged mobile robot.
[0028]
[Means for Solving the Problems]
In order to solve the above problem, the legged mobile robot according to the present invention is provided with a foot mechanism on a plurality of movable legs connected to the body, and a lower limb including the plurality of movable legs and the foot mechanism. A legged mobile robot that moves on a moving surface using the base unit, wherein the foot mechanism is configured based on a shape of the base unit having a hardness against a force applied from the body, the lower limbs and the moving surface, and a shape of the base unit. And a flexible portion whose characteristics change. According to this foot mechanism, since the flexibility of the flexible portion changes depending on the shape of the base or the like, for example, a reduction in the area of the effect generation execution surface can be suppressed.
[0029]
In order to solve the above problem, a legged mobile robot according to the present invention is provided with a foot mechanism on a plurality of movable legs connected to a body, and a lower limb including the plurality of movable legs and a foot mechanism. A leg-type mobile robot that moves on a moving surface by using the body unit, the body unit, a base unit having a hardness against a force applied from a lower limb and a moving surface, and the body unit is fixed to the base unit. In addition, it is formed by a flexible portion whose thickness on the moving surface side is distributed in a concave shape at the central portion and the peripheral portion. According to this foot mechanism, since the peripheral portion is in contact with the moving surface, the reduction of the area of the effect generation execution surface can be suppressed.
[0030]
In order to solve the above problem, a legged mobile robot according to the present invention is provided with a foot mechanism on a plurality of movable legs connected to a body, and a lower limb including the plurality of movable legs and a foot mechanism. And the leg mechanism is formed by laminating a plurality of materials having mutually different characteristics in a horizontal direction or a vertical direction with respect to the moving surface. According to this foot mechanism, since the center portion, the peripheral portion, and the outermost peripheral portion have different hardnesses, the reduction in the area of the effect generation execution surface can be suppressed.
[0031]
In order to solve the above problem, a legged mobile robot according to the present invention is provided with a foot mechanism on a plurality of movable legs connected to a body, and a lower limb including the plurality of movable legs and a foot mechanism. A leg-type mobile robot that moves on a moving surface by using a frictional distribution characteristic of the moving surface of the foot mechanism and a surface that is in contact with the ground, a central portion of the grounded surface, a periphery of the central portion, And the outermost peripheral portion of the peripheral portion. According to this foot mechanism, the central portion, the peripheral portion, and the outermost peripheral portion have different friction distribution characteristics, and the magnitude is large, medium, and small in the order of the peripheral portion, the central portion, and the outermost peripheral portion. Therefore, the moving surface is firmly captured at the peripheral portion and the central portion without being caught on the moving surface at the outermost peripheral portion.
[0032]
A foot mechanism of a legged mobile robot according to the present invention is provided with a legged movement provided on a side that comes into contact with a moving surface of a plurality of movable legs connected to a body of the legged mobile robot in order to solve the above problem. A foot mechanism for a robot, the base mechanism being connected to the movable leg and having a rigidity against a force applied from the torso, the lower limbs and the moving surface, and a flexible member whose characteristics are changed based on a shape of the base. Formed by the parts. According to this foot mechanism, since the flexibility of the flexible portion changes depending on the shape of the base or the like, for example, a reduction in the area of the effect generation execution surface can be suppressed.
[0033]
A foot mechanism of a legged mobile robot according to the present invention is provided with a legged movement provided on a side that comes into contact with a moving surface of a plurality of movable legs connected to a body of the legged mobile robot in order to solve the above problem. A foot mechanism of a robot, wherein the body, a lower limb, and a base body having a hardness against a force applied from a moving surface, and a center portion and a peripheral portion fixed to the base portion and having a thickness on a moving surface side. And a flexible portion distributed in a concave shape. According to this foot mechanism, since the peripheral portion is in contact with the moving surface, the reduction of the area of the effect generation execution surface can be suppressed.
[0034]
A foot mechanism of a legged mobile robot according to the present invention is provided with a legged movement provided on a side that comes into contact with a moving surface of a plurality of movable legs connected to a body of the legged mobile robot in order to solve the above problem. A foot mechanism of a robot, wherein a plurality of materials having mutually different characteristics are stacked vertically or horizontally with respect to the moving surface. According to this foot mechanism, since the center portion, the peripheral portion, and the outermost peripheral portion have different hardnesses, the reduction in the area of the effect generation execution surface can be suppressed.
[0035]
A foot mechanism of a legged mobile robot according to the present invention is provided with a legged movement provided on a side that comes into contact with a moving surface of a plurality of movable legs connected to a body of the legged mobile robot in order to solve the above problem. In the foot mechanism of the robot, the friction distribution characteristics of the moving surface and the surface contacting the ground, the central portion of the contact surface, the peripheral portion around the central portion, and further the outermost peripheral portion of the outer periphery of the peripheral portion. And make it different. According to this foot mechanism, the central portion, the peripheral portion, and the outermost peripheral portion have different friction distribution characteristics, and the magnitude is large, medium, and small in the order of the peripheral portion, the central portion, and the outermost peripheral portion. Therefore, the moving surface is firmly captured at the peripheral portion and the central portion without being caught on the moving surface at the outermost peripheral portion.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described. First, FIG. 1 shows an appearance in which a “human-type” or “human-type” legged mobile robot 1 used in the embodiment of the present invention is viewed from obliquely forward while standing upright. As shown in the figure, the legged mobile robot 1 has a head unit 3 connected to a predetermined position of a trunk (trunk) unit 2 and has two upper limb units 4R / 4L and two lower limb units 5R. / 5L are connected to each other (however, each of R and L is a suffix indicating each of right and left. The same applies hereinafter).
[0037]
The head unit 3 is connected to a substantially uppermost center of the trunk unit 2 by a neck joint 6. The upper limb unit 4R / 4L for each of the right and left ₁ R / 4 ₁ L, elbow joint 4 ₂ R / 4 ₂ L, forearm 4 ₃ R / 4 ₃ L, and are connected at the left and right side edges above the trunk unit 2 by shoulder joints 7R / 7L.
[0038]
The left and right lower limb units 5R / 5L are ₁ R / 5 ₁ L, knee joint 5 ₂ R / 5 ₂ L, shin part 5 ₃ R / 5 ₃ L, ankle 5 ₄ R / 5 ₄ L and foot 5 ₅ R / 5 ₅ L, and are connected at substantially the lowermost end of the trunk unit 2 by hip joints 8R / 8L. Thigh 5 ₁ R / 5 ₁ L and knee joint 5 ₂ R / 5 ₂ L and shin 5 ₃ R / 5 ₃ L constitutes a movable leg, and this movable leg has an ankle 5 ₄ R / 5 ₄ Foot 5 through L ₅ R / 5 ₅ L are connected with a predetermined degree of freedom.
[0039]
FIG. 2 schematically shows the configuration of the degrees of freedom of the joints included in the legged mobile robot 1. The neck joint 6 supporting the head unit 3 has three degrees of freedom of a neck joint yaw axis 101, a neck joint pitch axis 102, and a neck joint roll axis 103.
[0040]
The upper limb unit 4R / 4L includes a shoulder joint pitch axis 107, a shoulder joint roll axis 108, an upper arm yaw axis 109, an elbow joint pitch axis 110, a forearm yaw axis 111, a wrist joint pitch axis 112, and a wrist. It is composed of a joint roll wheel 113 and a hand 114. The hand 114 is actually a multi-joint / multi-degree-of-freedom structure including a plurality of fingers. However, since the operation of the hand 114 has little contribution or influence on the posture control and the walking control of the robot apparatus 1, it is assumed in this specification that the degree of freedom is zero. Therefore, each arm has seven degrees of freedom.
[0041]
The trunk unit 2 has three degrees of freedom, namely, a trunk pitch axis 104, a trunk roll axis 105, and a trunk yaw axis 106.
[0042]
The lower limb unit 5R / 5L includes a hip joint yaw axis 115, a hip joint pitch axis 116, a hip joint roll axis 117, a knee joint pitch axis 118, an ankle joint pitch axis 119, an ankle joint roll axis 120, and a foot. 121 (foot 5 in FIG. 1) ₅ R / 5 ₅ Same as L. ). In the present specification, the intersection of the hip joint pitch axis 116 and the hip joint roll axis 117 defines the hip joint position of the robot device 1. Although the foot of the human body is actually a structure including a sole with multiple joints and multiple degrees of freedom, the sole of the robot apparatus 1 has zero degrees of freedom. Therefore, each lower limb unit has six degrees of freedom.
[0043]
Summarizing the above, the robot apparatus 1 as a whole has a total of 3 + 7 × 2 + 3 + 6 × 2 = 32 degrees of freedom. However, the legged mobile robot 1 is not necessarily limited to 32 degrees of freedom. Needless to say, the degree of freedom, that is, the number of joints, can be appropriately increased or decreased according to design / production constraints and required specifications.
[0044]
Each degree of freedom of the legged mobile robot 1 as described above is actually implemented using an actuator. That is, each joint is provided with an actuator. The operation of the robot is realized by driving the actuator. Due to various demands such as approximating the natural shape of a person by giving extra bulge on the appearance of the device, and controlling the posture of an unstable structure such as bipedal walking, the joint actuator is small and lightweight. It is preferable that
[0045]
In this embodiment, a small AC servo actuator of a type directly connected to a gear and of a type in which a servo control system is integrated into a motor unit with a single chip is mounted. A small AC servo-actuator applicable to a legged mobile robot is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-299970 already assigned to the present applicant.
[0046]
FIG. 3 schematically shows a control system and an actuator configuration of the legged mobile robot 1. As shown in the figure, the legged mobile robot 1 performs a cooperative operation between the trunk unit 2, the head unit 3, the upper limb unit 4R / 4L, and the lower limb unit 5R / 5L, which represent human limbs. The control unit 10 performs adaptive control for realizing the control.
[0047]
The operation of the entire legged mobile robot 1 is totally controlled by the control unit 10. The control unit 10 exchanges data and commands with a main control unit 11 composed of main circuit components such as a CPU (Central Processing Unit) described later, a RAM, a flash ROM, and the like, and a power supply circuit and robot components. And a peripheral circuit 12 including an interface and the like.
[0048]
FIG. 4 shows an outline of a control system configuration of the legged mobile robot 1. The main control unit 11 includes a CPU 13, a RAM 14, a ROM 15 storing operation patterns and the like, an A / D converter 17 for converting outputs of various sensors 30 and 31 mounted on the legged mobile robot into digital signals. Are connected by a bus 16.
[0049]
The CPU 13 sets the locomotion by the lower limb, the ZMP trajectory, the trunk motion, the upper limb motion, the waist height, etc., based on the information stored in the ROM 15 and the outputs of various sensors, and sets these. The command value to each joint according to the setting contents is determined. The ZMP trajectory referred to here means a trajectory of the ZMP moving, for example, during a walking motion of the robot.
[0050]
The AC servo actuators Ai provided at the respective joints are connected to the main controller 11 via the bus 16 and can receive the respective joint command values calculated by the CPU 13. The AC servo actuator Ai is driven according to the command value, and the operation of the legged mobile robot 1 is realized.
[0051]
The installation location of the control unit 10 is not particularly limited. In FIG. 3, it is mounted on the trunk unit 2, but may be mounted on the head unit 3. Alternatively, the control unit 10 may be provided outside the robot to communicate with the body of the legged mobile robot 1 by wire or wirelessly.
[0052]
Each joint degree of freedom in the legged mobile robot 1 shown in FIG. 2 is realized by the corresponding AC servo actuator Ai. That is, the head unit 3 includes a neck joint yaw axis actuator A2, a neck joint pitch axis actuator A3, and a neck joint roll axis actuator expressing the neck joint yaw axis 101, the neck joint pitch axis 102, and the neck joint roll axis 103, respectively. A4 is provided.
[0053]
In addition, the head unit 3 is provided with a CCD (Charge Coupled Device) camera for imaging an external situation, a distance sensor for measuring a distance to an object located ahead, and an external sound. A microphone for collecting sound, a speaker for outputting sound, a touch sensor for detecting pressure received by a physical action such as “stroke” and “hit” from the user, and the like are provided.
[0054]
The trunk unit 2 includes a trunk pitch axis actuator A5, a trunk roll axis actuator A6, and a trunk yaw axis actuator that represent each of a trunk pitch axis 104, a trunk roll axis 105, and a trunk yaw axis 106. A7 is provided. Further, the trunk unit 2 includes a battery serving as a power supply for starting the robot 1. This battery is constituted by a chargeable / dischargeable battery.
[0055]
The upper limb unit 4R / 4L is ₁ R / 4 ₁ L and elbow joint 4 ₂ R / 4 ₂ L and forearm 4 ₃ R / 4 ₃ L, each of which is represented by a shoulder joint pitch axis 107, a shoulder joint roll axis 108, an upper arm yaw axis 109, an elbow joint pitch axis 110, a forearm yaw axis 111, a wrist joint pitch axis 112, and a wrist joint roll axis 113. Shoulder joint pitch axis actuator A8, shoulder joint roll axis actuator A9, upper arm yaw axis actuator A10, elbow joint pitch axis actuator A11, elbow joint roll axis actuator A12, wrist joint pitch axis actuator A13, wrist joint roll axis actuator A14 are provided. Have been.
[0056]
The lower limb unit 5R / 5L is connected to the thigh 5 ₁ R / 5 ₁ L and knee joint 5 ₂ R / 5 ₂ L and shin 5 ₃ R / 5 ₃ L, ankle 5 ₄ R / 5 ₄ L, foot 5 ₅ R / 5 ₅ L, the hip joint yaw axis 115, the hip joint pitch axis 116, the hip joint roll axis 117, the knee joint pitch axis 118, the ankle joint pitch axis 119, and the hip joint yaw axis actuator A16 expressing each of the ankle joint roll axes 120 , A hip joint pitch axis actuator A17, a hip joint roll axis actuator A18, a knee joint pitch axis actuator A19, an ankle joint pitch axis actuator A20, and an ankle joint roll axis actuator A21.
[0057]
As described above, the actuators A2, A3,... Used for each joint are constituted by small AC servo-actuators of a type directly connected to a gear and a single-chip servo control system mounted in a motor unit. be able to.
[0058]
For each mechanism unit such as trunk unit 2, head unit 3, each upper limb unit 4R / 4L, each lower limb unit 5R / 5L, etc., sub-control units 20, 21, 22R / 22L, 23R / 23L of the actuator drive control unit. Is deployed. Further, a grounding confirmation sensor 30R / 30L for detecting whether the sole of the foot 121 of each lower limb unit 5R / 5L has landed is mounted, and a posture sensor for measuring the posture is provided in the trunk unit 2. Equipped with 31.
[0059]
The ground contact confirmation sensors 30R / 30L are configured by, for example, proximity sensors or micro switches installed on the soles. The posture sensor 31 is configured by, for example, a combination of an acceleration sensor and a gyro sensor.
[0060]
Based on the output of the ground contact confirmation sensors 30R / 30L, it is possible to determine whether each of the left and right legs is currently in a standing or idle state during an operation such as walking or running. In addition, the output of the posture sensor 31 can detect the inclination and posture of the trunk.
[0061]
The main controller 11 can dynamically correct the control target in response to the outputs of the sensors 30R / 30L and 31. More specifically, adaptive control is performed on each of the sub-control units 20, 21, 22R / 22L, and 23R / 23L, and the sub-control unit transmits each joint command value from the main control unit 11 to an AC servo.・ Send to the actuator Ai. The AC servo actuator Ai is driven according to each joint command value from the main control unit 11, and the operation of the legged mobile robot is realized.
[0062]
Foot 5 ₅ R / 5 ₅ L (121) is in the two lower limb units 5R / 5L, and the thigh 5 ₁ R / 5 ₁ L and knee joint 5 ₂ R / 5 ₂ L and shin 5 ₃ R / 5 ₃ Ankle 5 on the leg of L ₄ R / 5 ₄ It is mounted with two degrees of freedom via L. This is the degree of freedom obtained by the ankle joint pitch axis 119 and the ankle joint roll axis 120.
[0063]
This foot 5 ₅ R / 5 ₅ L (121) is a base portion 21 shown in FIG. And a flexible portion 22 to be provided. The foot 5 shown in FIG. ₅ R / 5 ₅ L (121) is a configuration in which the foot upper surface portion 42, the bottom flexible portion 43, and the moving surface contact portion 44 of the modeled foot portion 40 shown in FIGS. 6 and 7 are embodied.
[0064]
First, the modeled foot 40 shown in FIGS. 6 and 7 will be described. FIG. 6 is a perspective view of the modeled foot 40, and FIG. 7 is a schematic cross-sectional view. Note that, in these figures, a discrete expression is used in order to schematically show the bottom flexible object and the moving surface contact portion which may be continuous in nature. It is an expression for explaining the concept of the present invention from mechanical characteristics.
[0065]
The ankle connecting part 41 fixed on the foot upper surface part 42 includes the ankle part 5 of FIG. ₄ R / 5 ₄ L secures and connects the aforementioned ankle joint pitch axis 119 and the ankle joint roll axis 120. The foot upper surface portion 42 to which the ankle connection portion 41 is fixed corresponds to the base portion 21 in FIG. 5 and is a portion corresponding to the instep. These parts are places for transmitting the torque generated by the lower limbs, the reaction force from the moving surface, the moment, and the like, and must have properties capable of supporting them. Materials that are extremely susceptible to deformation are ineligible. Therefore, superalloys, light metals, reinforced plastics, and the like are suitable.
[0066]
As will be described later, the shape of the foot upper surface portion 42 is related to the bottom flexible portion 43, and by appropriately designing the shape of the foot upper surface portion 42, the characteristics of the bottom flexible portion 43 are adjusted. Therefore, it becomes possible to adjust the characteristics of the foot.
[0067]
For example, depending on the shape of the foot upper surface portion 42, the thickness of the bottom flexible portion 43 can have a distribution, and can effectively function as an element for determining movement performance.
[0068]
The bottom flexible portion 43 modeled by a spring is a characteristic portion of the foot 40 together with the foot upper surface 42. The foot flexible portion 43 needs to be considered in combination with an elastic element and a viscous element, as well as those elements. In addition, these elements may be linear, non-linear, continuous, or discontinuous, such as a step characteristic, a hysteresis, or a dead zone characteristic. The thickness dimension and the shape of the foot flexible portion 43 in the cross-sectional direction do not need to be the same, and various shapes can be considered as described later. In the present invention, the characteristics of this portion can be selected in order to appropriately adjust the contact state and its change.
[0069]
The moving surface contact portion 44 is a contact portion with the moving surface. This part is also a part that greatly contributes to exercise performance. The moving surface contact portion 44 is a portion that applies the characteristics determined by the bottom flexible portion 43 to the moving surface, and is a portion that determines friction, durability, and the like.
[0070]
However, the bottom flexible portion 43 and the moving surface contact portion 44 can be formed of the same material and the same structure. That is, some functions (performances) for movement can be determined by selecting the material.
[0071]
Hereinafter, details of the foot 121 shown in FIG. 5, which is an embodiment of the modeled foot 40, will be described with reference to a cross-sectional view (FIG. 8). The base flexible portion 22 is bonded to the base portion 21 to which the ankle connecting portion 41 to which the ankle portion having the two degrees of freedom is connected is fixed, for example, by bonding. The base portion 21 has such a hardness that it is not deformed by the torque generated by the lower limbs and the reaction force from the moving surface, and that secures a supporting moment. The flexible portion 22 has both the functions of the bottom flexible portion 43 and the moving surface contact portion 44 shown in FIGS. 6 and 7. By appropriately selecting the shape of the base 21, it is possible to adjust the contact pressure distribution on the moving surface 19. In addition, R is provided at an outer edge portion of the foot flexible portion 22 that comes into contact with the moving surface to prevent unnecessary catching on the moving surface.
[0072]
In particular, in the specific example of FIG. 8, when the central portion of the base portion 21 is distinguished from its peripheral portion, the thickness of the base portion 21 is set such that the central portion has the smallest thickness and both ends in the cross-section longitudinal direction have the largest thickness. It is concavely thinner toward the moving surface. That is, the central portion of the base portion 21 is formed as a concave surface separated from the moving surface. Then, according to the shape of the base portion 21, the flexible portion 22 bonded to the base portion 21 has a thicker central portion and thinner both ends (front end and rear end) in the longitudinal direction of the cross section, so that the thickness has a distribution. be able to. As a result, the flexible portion 22 bonded to the base portion 21 thinned in a concave shape becomes softer toward the center.
[0073]
For this reason, even if the ZMP comes to the central portion, the central portion is soft, and both ends are not softer than that, so that the contact surface of the foot contacting the moving surface does not bend, for example, in the opposite direction to the moving surface, The contact area with the moving surface does not decrease. That is, the area of the drag generating effective surface is not reduced, but becomes stronger against the moment around the yaw axis generated by the operation of the legged mobile robot 1, and the posture of the legged mobile robot 1 can be kept stable.
[0074]
As described above, the legged mobile robot 1 using the foot having the structure shown in FIGS. 5 and 8 forms the concave surface that is separated from the moving surface in the base 21 so that the foot can be moved by the ZMP. Even if the shape of the part changes, it is possible to suppress the deformation of the shape of the drag generation effective surface that generates drag with respect to the moment about the yaw axis and a reduction in the area, and it is possible to maintain a stable posture. Become. In addition, the contact pressure on the moving surface can be increased at a position distant from the center of the foot, and the moment against the yaw axis generated in the legged mobile robot 1 can be increased. Furthermore, it is possible to prevent an extreme increase in the frictional force generated on the road surface, and to prevent the robot from tripping. In addition, a curved surface that is convex in the outer peripheral direction is formed on the peripheral edge of the foot. Accordingly, a trip can be prevented, and even when the legged mobile robot 1 falls, a smooth transition to a safe falling operation can be achieved.
[0075]
Hereinafter, another specific example of the foot will be described. First, the foot 122 as a second specific example has a configuration as shown in cross section in FIG. Unlike the foot part 121 whose cross section is shown in FIG. 8, the bottom flexible part 43 and the moving surface contact part 44 shown in FIGS. 6 and 7 are materially and structurally separated. That is, the moving surface contact portion 23 is provided separately from the bottom flexible portion 22. The moving surface contact portion 23 is bonded to the bottom flexible portion 22 by, for example, bonding. Since the moving surface contact portion 23 comes into contact with the moving surface, the moving surface contact portion 23 determines the friction characteristics and the like. Similar to the foot portion 121 whose cross section is shown in FIG. 8, the ground pressure distribution can be adjusted by appropriately selecting the shape of the base portion 21. In addition, R is provided on the outer edge of the contact portion with the moving surface to prevent unnecessary catching.
[0076]
For this reason, even if the ZMP comes to the central portion, the central portion is soft, and both ends are not softer than that, so that the contact surface of the foot contacting the moving surface does not bend, for example, in the opposite direction to the moving surface, The contact area with the moving surface does not decrease. That is, the area of the drag generation effective surface does not decrease, but becomes stronger against the moment around the yaw axis generated by the operation of the legged mobile robot, and the posture of the legged mobile robot can be stably maintained.
[0077]
As described above, the legged mobile robot using the foot 122 having the structure shown in the cross section in FIG. 9 forms the concave surface facing away from the moving surface in the base 21 so that the foot can be moved by the ZMP. Even if the shape changes, it is possible to suppress the deformation of the shape of the effective drag generation surface and the decrease in the area of the drag generation effective surface which generates a drag against the moment about the yaw axis, and the posture can be stably maintained. . Further, the contact pressure on the moving surface can be increased at a position distant from the center of the foot, and the moment against the yaw axis generated in the legged mobile robot can be increased. Furthermore, it is possible to prevent an extreme increase in the frictional force generated on the road surface, and to prevent the robot from tripping. In addition, a curved surface that is convex in the outer peripheral direction is formed on the peripheral edge of the foot. Thus, a trip can be prevented, and even when the legged mobile robot falls, a smooth transition to a safe falling operation can be achieved. Further, in the case where the flexible portion 22 is made of a material that is easily damaged, the flexible portion 22 can be protected by the contact portion 23.
[0078]
Next, as shown in a cross section in FIG. 10, the foot portion 123 as the third specific example does not give a characteristic shape to the base portion 24 but gives a characteristic to the shape of the bottom flexible portion 25. ing. That is, the base portion 24 has a flat plate shape whose cross section is linear in the longitudinal direction, and is not a concave surface separated from the moving surface as in the base portion 21 described above. For example, the central portion of the flexible portion 25 that is adhered to and adhered to the base portion 24 is a concave surface separated from the moving surface. A movable surface contact portion 26 having a function of protecting the flexible portion 25 is, for example, bonded and bonded to the flexible portion 25.
[0079]
Even when the ZMP comes to the center, the center of the foot 123 having such a structure approaches the moving surface due to the load of the robot, but the both ends are thicker than the center, so that the moving surface is not so much. do not get closer. Thus, the contact surface of the foot contacting the moving surface does not bend, for example, in the direction opposite to the moving surface, and the contact area with the moving surface does not decrease. That is, the area of the drag generation effective surface does not decrease, but becomes stronger against the moment around the yaw axis generated by the operation of the legged mobile robot, and the posture of the legged mobile robot can be stably maintained.
[0080]
As described above, the legged mobile robot using the legs 123 having the structure shown in cross section in FIG. 10 forms a concave surface separated from the moving surface at the center of the flexible portion 25 bonded to the base 24. Thereby, even if the shape of the foot portion changes due to the movement of the ZMP, it is possible to suppress the deformation of the shape of the drag generation effective surface which generates a drag against the moment about the yaw axis and a decrease in the area, and Can be kept stable. Further, the contact pressure on the moving surface can be increased at a position distant from the center of the foot, and the moment against the yaw axis generated in the legged mobile robot can be increased. Furthermore, it is possible to prevent an extreme increase in the frictional force generated on the road surface, and to prevent the robot from tripping. In addition, a curved surface that is convex in the outer peripheral direction is formed on the peripheral edge of the foot. Thus, a trip can be prevented, and even when the legged mobile robot falls, a smooth transition to a safe falling operation can be achieved. Furthermore, in the case where the flexible portion 25 is made of a material that is easily damaged, the flexible portion 25 can be protected by the contact portion 26.
[0081]
Next, as shown in a cross section in FIG. 11, a foot 124 as a fourth specific example is formed below the foot upper surface 52 with a flat plate-shaped foot 52 to which the ankle connecting portion 51 is fixed. A base portion is constituted by the core portion 53 thus formed, and a bottom flexible portion 54 having different characteristics depending on the shape of the core portion 53 is fixed to the core portion 53. That is, the base portion of the foot portion 124 includes the upper surface portion 52 connected to the movable leg via the ankle portion, and the core portion 53 located between the upper surface portion 53 and the flexible portion 54. The effect is to give the effect to the flexible part by changing the shape of the contact and adjust the contact pressure. Of course, the upper surface portion 52 and the core portion 53 of the base portion are hard enough not to be deformed by the torque generated by the lower limb and the reaction force from the moving surface and to secure a supporting moment.
[0082]
In particular, in the specific example of FIG. 11, when the central portion of the core portion 53 is distinguished from its peripheral portion, the thickness of the core portion 53 is the thinnest at the central portion 53C, and the two end portions 53E, 53E in the cross-sectional longitudinal direction are thin. It is thinner concavely toward the moving surface so as to be thicker. That is, the central portion 53C of the core 53 is formed as a concave surface separated from the moving surface. Then, the flexible portion 54 fixed to the core portion 53 can have a thickness distribution by increasing the thickness of the central portion 54C and thinning the both ends 54E and 54E in the longitudinal direction of the cross section according to the shape of the core portion. . Thereby, the flexible portion 54 fixed to the core portion 53 thinned in a concave shape becomes softer toward the central portion 54C.
[0083]
For this reason, even if the ZMP comes to the central portion, the central portion is soft, and both ends are not softer than that, so that the contact surface of the foot contacting the moving surface does not bend, for example, in the opposite direction to the moving surface, The contact area with the moving surface does not decrease. That is, the area of the drag generating effective surface is not reduced, but becomes stronger against the moment around the yaw axis generated by the operation of the legged mobile robot 1, and the posture of the legged mobile robot 1 can be kept stable.
[0084]
In addition, the ground contact portion with the moving surface can keep the supporting moment high when it is closer to the outer peripheral portion. Further, the thinner flexible portion has the effect of suppressing shear deformation in the horizontal plane direction, and as a result, it is possible to prevent unexpected stick-slip vibration of the ground contact portion. In addition, as described above, in order to prevent a stumbling or the like, adjustment is also made such that an R is provided at a corner of the flexible portion 54.
[0085]
By the way, as for the method of fixing the flexible portion 54 and the core portion 53, there are some materials which are difficult to join or bond in reality. In such a case, if the flexible object can be cast as a mold, as shown in FIG. 11, a fixing portion 54S whose tip is swelled spherically is formed. The flexible portion 54 can be fixed to the core 53 by fitting the fixing portion 54S into a hole 53A having a wide end formed in the core 53. In the vicinity of the outer edge portion where the flexible portion 54 contacts the upper surface portion 52, a fixing portion 56G is provided so as to exactly wrap the core portion 53. By fixing the core portion 53 so that the flexible portion 54 is sandwiched between the core portion 53 and the upper surface portion 52, more secure fixing is possible.
[0086]
FIG. 12 is a conceptual cross-sectional view of a fifth specific example (foot 125) in which the shape of the core 55 is different from that of the fourth specific example shown in FIG. In the specific example of FIG. 11, R is provided on the outer peripheral portion of the grounding portion of the core portion. However, in the case where there is a problem in processing or the flexible portion 56 has excellent characteristics such as sufficiently withstanding deformation. , The corner R of both ends 55E, 55E of the core portion 55 is omitted, and a shape such as a slight radius or chamfer is provided at both ends 56E, 56E of the flexible portion 56.
[0087]
In the specific example of FIG. 12 as well, the fixing portion 56S whose tip is swelled spherically is formed in the flexible portion. The flexible portion 56 can be fixed to the core 55 by fitting the fixing portion 56S into a hole 55A having a widened end formed in the core 55. In the vicinity of the outer edge portion where the flexible portion 56 contacts the upper surface portion 52, a fixing portion 56G is provided so as to just surround the core portion 55. The core portion 55 is fixed such that the flexible portion 56 is sandwiched between the flexible portion 56 and the upper surface portion 52, so that more secure fixing is possible.
[0088]
FIG. 13 is a cross-sectional view of a sixth specific example (foot 126) of the specific examples shown in FIGS. 11 and 12 in which the fixing method of the upper surface 52 side of the flexible portion 56 is different. In order to further secure the fixing, the end portion 56G (fixed portion) of the flexible portion 56 on the upper surface portion 52 side is expanded, and is fitted and fixed in the concave portion formed in the core portion 55 and the upper surface portion 52. In the drawing, the upper surface portion 52 and the core portion 55 are separated, but these are formed as one body, and the flexible portion may be shaped by casting.
[0089]
FIG. 14 shows a design example of the second specific example shown in FIG. 9 (this is referred to as a foot 127 of the seventh specific example). The core portion 55 and the flexible portion 56 are equivalent to the configuration shown in FIG. Characteristically, a durable contact portion 57 is provided so as to surround the flexible portion 56. By configuring the flexible part separately, the range of choice of materials is widened, and it becomes possible to configure the foot mechanism with elements such as surface pressure adjustment, friction characteristics, strength, durability, etc. as more excellent characteristics. .
[0090]
FIG. 15 shows an eighth specific example (foot 128) characterized by a structure in which a reinforcing material is provided near the outer edge of the flexible part of the fifth specific example shown in FIG. When the bottom flexible portion 56 also functions as the moving surface contact surface, depending on the material, there may be a problem in durability, or the surface pressure or the like near the ground contact portion of the moving surface may need to be adjusted. When the reinforcing member 58 is introduced, for example, when the flexible portion 56 is cast by a mold as a mold, sufficient measures are taken to adjust the durability and surface pressure of the material. That is, by inserting the reinforcing member 58 into the flexible portion 56, it is possible to secure strength and durability and to improve the movement performance.
[0091]
The flexible portion used in each of the above specific examples may be made of a viscous and elastic material, for example, rubber, α-gel (trade name), silicon, memory foam (trade name), resin, or the like.
[0092]
In addition, there is a possibility that a mechanical element having elasticity, viscosity, friction, and the like can be realized. 16 shows a cross-sectional view of an example thereof (a ninth specific example of the mechanism of the foot portion 130, and FIG. 17 shows a view from the lower surface. In the ninth specific example, a plurality of A structure is provided in which the spring element 62 is provided, and further below the moving surface contact portion 63. That is, a structure in which the plurality of spring elements 62 are sandwiched between the foot upper surface portion 61 and the moving surface contact portion 63. One spring element 62i fixes, for example, three metal leaf springs 621, 622, and 623 having different lengths on one side of the end 620 on the upper surface connection portion 64 side described later. The other end 621b of the longest leaf spring 621 is fixed to a contact portion connection portion 65 described later.
[0093]
For example, eight spring elements 62 ₁ ~ 62 ₈ Are connected to the foot upper surface portion 61 at one end, and are connected to the moving surface contact portion 63 at the other end as contact portion connection portions 65. In particular, in this example, as shown in FIG. ₁ ~ 62 ₈ Are arranged concentrically around an intersection of an extension of the straight line connecting the center of the upper surface portion connection portion 64 and the center of the contact portion connection portion 65 to the center portion side.
[0094]
The spring element 62i has a non-linear characteristic as shown in FIG. In FIG. 18, in particular, the characteristic of the hardness shown on the vertical axis with respect to the magnitude of the deformation shown on the horizontal axis is a multi-stage characteristic. When the magnitude of the deformation is from 0 to D1, the slope is I1, from D1 to D2 is I2, and from D2 to D3 is I3.
[0095]
Further, in the ninth specific example, the material and shape of the moving surface contact portion 63 are appropriately selected, and the arrangement of the spring element 62i, the contact portion connection portion 65, and the upper surface connection portion 64 is changed. It is possible to adjust the performance as a foot mechanism.
[0096]
Although a plurality of specific examples have been described above, in any of the examples, the contact force, the pressure, and the friction force due to the change thereof can be adjusted, and the motion performance of the robot can be secured. In addition, it is possible to adjust the supporting moment by the contact force, the pressure and the change thereof, and it is possible to secure the exercise performance. Further, it is possible to secure the strength and further improve the durability.
[0097]
In the following, a structure common to each of the specific examples described above, that is, a structure in which a concave portion that becomes softer near the center portion on the bottom portion functions, and how the above-described effect is obtained. Explain whether you can get it.
[0098]
First, a change in the cross-sectional state of the foot 131 when weight is applied will be described with reference to FIG. In this case, a concave portion 133 is provided on the bottom surface, and a flexible portion 132 is provided at the center of the concave portion 133 so that the distribution becomes softer near the center. As a result, when no load is applied, as shown in FIG. 19A, apart from the vicinity of the outer peripheral portion 134, separation from the moving surface (the ground) 135 or generation of an excessive ground pressure is prevented. Even when a load is applied, as shown in FIG. 19B, even if the sole 131 mechanism is deformed, the main load portion 134 to which the floor reaction force 136 is applied is always kept outside. It is possible to suppress a decrease in the supporting moment.
[0099]
Therefore, the legged mobile robot has a structure in which the concave portion 133 is provided on the bottom surface of the foot 131 so as to become softer near the center, so that the legged mobile robot can move even if the shape of the foot changes due to the movement of the ZMP. It is possible to suppress deformation of the shape of the effective drag generation surface that generates a drag against a moment about the yaw axis generated by the operation of the robot, and to reduce the area thereof, and to maintain a stable posture thereof. Further, the contact pressure on the road surface can be increased at a position distant from the center of the foot, and it can be made robust against the moment about the yaw axis generated in the legged mobile robot. Furthermore, it is possible to prevent an extreme increase in the frictional force generated on the road surface, and to prevent the robot from tripping.
[0100]
In addition, as shown in FIG. 20, even when the user steps on a step, the flexible portion 132 near the arch of the sole of the foot. There is no interference with the sole mechanism body due to the steps, and the contact pressure is suppressed so that unnecessary rise does not occur. Therefore, the moving performance can be improved with respect to the unevenness and the steps on the moving surface, and the characteristics can be robust.
[0101]
Further, as shown in FIG. 21, even for a carpet having a long bristle foot, a concave sole periphery is formed into a smooth shape to prevent the carpet from being caught, and the bristle feet of the carpet bite into the flexible portion 132 in the center. Thus, it is possible to secure the frictional force and generate and adjust the moment in the yaw direction. The characteristics of the carpet are slippery and soft. From the point of view of the legged mobile machine, it is difficult to secure a moment in the yaw direction and increase the supporting moment. In addition, depending on the shape of the sole, there is a danger of being caught and generating a falling moment, but the danger is avoided by the present invention.
[0102]
Further, as shown in FIG. 22, in each specific example of the present invention, since the shape of the peripheral portion 134 is provided with R, this portion does not catch on the ground (moving surface). As a result, unlike the related art, the friction force is excessively increased, and no overturning moment is generated. In addition, when the friction or the like is increased by appropriately rounding this portion, the effect of suppressing the occurrence of the overturning moment can be expected by slipping the entire sole surface.
[0103]
In addition, as shown in FIG. 23, when the ground is supported by the flexible portion 132 corresponding to the arch at the convex portion or the step, or when the sliding from the upper step of the step is stopped, the flexible structure has friction. In addition to securing the shape, it also has the effect of adjusting the shape change appropriately and adapting to the ground condition.
[0104]
FIG. 24 and FIG. 25 are examples of deformation of the flexible surface of the sole. FIG. 24 shows a so-called standard deformation state. Even with this, it can be said that it is possible to generate a supporting moment to some extent, but there is a limit. In order to enlarge this, not only the material is made flexible, but also the flexible portion 139 can maintain the deformation to some extent, that is, by giving a hysteresis characteristic, it is deformed as shown in FIG. And the legged moving body can be supported more safely even when there is a danger of slipping down due to a step or the like.
[0105]
Although the operation of the specific example having the concave portion that becomes softer near the center portion on the bottom surface of the foot portion has been described so far, as shown in FIGS. A flexible portion 142 having a rectangular cross section may be provided on 141. With the foot 140 having such a configuration, even when the obstacle 143 or 144 capable of rolling with respect to the ground (moving surface) is stepped on, the walking control does not become unstable unlike the related art. In the conventional foot mechanism, a so-called tortoise-like state is formed, and with this as a fulcrum, it becomes like a seesaw, cannot generate a supporting moment, and has non-linear characteristics. In this specific example, by providing the flexible portion 142 below the base portion 141, if the obstacle is small (the obstacle 143) as shown in FIG. A support point for the sole is secured. Further, as shown in FIG. 27, even when the height is larger (the obstacle 144), there is an advantage that the height h at which the sole separates from the ground is small, and the number of unstable elements is small.
[0106]
By the way, as described above, the present invention is very characteristic in that a flexible object is attached to a hard surface (three-dimensional) serving as an upper surface. From the examples shown so far, various characteristics I1, I2 and I3 as shown in FIG. 18 and FIG. 28 can be given, so that various physical properties which could not be solved only by the types of materials and structures Characteristics can be adjusted widely.
[0107]
Unlike a wheeled or endless track type moving mechanism, a leg type moving mechanism realizes movement by discontinuous and discrete grounding of the toes, so that the time series characteristics around the grounding portion are important. Specifically, the time change of the contact pressure and the time change of the contact friction force can be managed and adjusted. FIG. 29 shows an example of the characteristic. When walking, the foot is extended, and the grounding (applying load), supporting, unloading, and separating (free leg) are repeated, but at the moment of grounding, the load on the ground should be A smaller one is preferred. Then, when the contact is completed, the supporting force is increased by an appropriate change in order to generate a high supporting moment. If the rise is slow, the supporting moment does not increase and stability cannot be ensured. However, even if it rises sharply, it may act as a overturning moment.
[0108]
Therefore, as described above, the grounding state is appropriately adjusted, and the structure is particularly effective with respect to dynamic changes.Moreover, by providing a flexible structure, even under poor conditions such as movement of a convex portion and other conditions. The technique of the present invention can be expected to improve the stability and mobility of the legged moving body.
[0109]
In the meantime, the shape of the base of the shaped foot and the shape of the flexible portion have been changed in order to make the characteristics near the bottom of the foot distributed, but in the present invention, the moving surface of the foot and the ground contact are further changed. As shown in FIG. 30, the friction distribution characteristics of the surface to be moved are, as shown in FIG. 30, the central portion 151 of the surface that contacts the moving surface, the peripheral portion 152 around the central portion, and the outermost peripheral portion 153 of the outer periphery of the peripheral portion. The configuration may be different. Here, the frictional force distribution characteristics are large, medium, and small in the order of the peripheral portion 152, the central portion 151, and the outermost peripheral portion 153.
[0110]
Alternatively, as shown in FIGS. 31 and 32, the foot portion may be formed by laminating a plurality of materials having mutually different characteristics in the horizontal direction with respect to the moving surface. Therefore, FIGS. 31 and 32 show a state where the flexible portion is viewed from above. In addition, it can be said that it shows a cross section obtained by cutting the flexible portion in the horizontal direction with respect to the moving surface.
[0111]
In particular, FIG. 31 shows a plurality of materials having characteristics different from each other, from the bottom flexible portion (1) 161 to the bottom flexible portion (7) 167, concentrically centered in the bottom flexible portion (1) 161. This is an arrangement in which the layers are stacked. The inner bottom flexible portion (1) 161 is made the softest, and the bottom flexible portions (2) 162, (3) 163,... (7) 167 become harder. That is, the inside is softest and the outside is hardest. Also, a central portion C composed of a flexible bottom portion (1) 161 and a flexible bottom portion (2) 162, a peripheral portion A composed of flexible bottom portions (3) 163, (4) 164, and (5) 165, and a flexible bottom portion When divided into the outermost peripheral portion O composed of the portions (6) 166 and (7) 167, the frictional force distribution characteristics may be different. The frictional force distribution characteristics are also large, medium, and small in the order of the peripheral portion A, the central portion C, and the outermost peripheral portion O.
[0112]
Also, FIG. 32 shows an ellipse having a plurality of materials having different characteristics from the bottom flexible portion (1) 171 to the bottom flexible portion (7) 177 with the bottom flexible portion (1) 171 inside similarly. This is an arrangement in which the layers are stacked in a shape. The inner bottom flexible portion (1) 171 is made the softest, and the bottom flexible portions (2) 172, (3) 173,. That is, the inside is softest and the outside is hardest. Also, a central portion C composed of a bottom flexible portion (1) 171 and a bottom flexible portion (2) 172, a peripheral portion A composed of a bottom flexible portion (3) 173, (4) 174, and (5) 175; When divided into the outermost peripheral portion O composed of the portions (6) 176 and (7) 177, the frictional force distribution characteristics may be different. The frictional force distribution characteristics are also large, medium, and small in the order of the peripheral portion A, the central portion C, and the outermost peripheral portion O.
[0113]
Further, as shown in FIG. 33, a plurality of materials having mutually different characteristics may be stacked in a direction perpendicular to the moving surface to form the foot. That is, the flexible portions (1) 181 to (6) 186 having different characteristics are stacked and arranged in the height direction. The layers may be stacked or the outer material may include the inner material. In addition, R is provided on the outer edge of the moving surface contact portion to prevent unnecessary catching.
[0114]
【The invention's effect】
As described above, the legged mobile robot according to the present invention is characterized in that the foot mechanism is characterized by a base body having a hardness against the forces from the torso, the lower limbs and the moving surface, and a characteristic based on the shape of the base. Is formed by the flexible portion that changes, so that it is possible to suppress a change in the effective force generation surface due to a change in the shape of the foot due to the ZMP movement.
[0115]
Further, the legged mobile robot according to the present invention, the foot mechanism, the trunk, the lower limb and a rigid base portion against the force from the moving surface, the base portion is fixed to the base portion, and the center position as the center portion When it is distinguished from the surrounding area, it is formed by a flexible part that makes the thickness of the central part concavely thinner toward the moving surface. Therefore, it is possible to suppress the change of the drag generating effective surface due to the change of the foot shape due to the ZMP movement. Can be.
[0116]
Further, the legged mobile robot according to the present invention forms the foot mechanism by laminating a plurality of materials having mutually different characteristics in the horizontal direction or the vertical direction with respect to the moving surface, so that the foot shape is formed by ZMP movement. It is possible to suppress a change in the drag generating effective surface due to the change.
[0117]
In addition, the legged mobile robot according to the present invention can determine the friction distribution characteristics between the moving surface of the foot mechanism and the surface contacting the ground, the central portion of the contacting surface, the peripheral portion around the central portion, and the outermost periphery of the peripheral portion. Since the difference is made between the outer peripheral portion and the outer peripheral portion, an appropriate frictional force is secured, and the outer peripheral portion does not get caught or slip on the moving surface.
[0118]
Further, the foot mechanism of the legged mobile robot according to the present invention includes a body portion having a hardness against the forces from the body, the lower limbs and the moving surface, and a flexible portion whose characteristics change based on the shape of the body portion. Therefore, it is possible to suppress a change in the effective force generation surface due to a change in the shape of the foot due to the ZMP movement.
[0119]
Further, the foot mechanism of the legged mobile robot according to the present invention has a body portion having a hardness to oppose the force from the body, the lower limbs and the moving surface, and the body portion is fixed to the body portion, and the center position is the center portion. When distinguished from the peripheral part, it is formed by a flexible part that makes the thickness of the central part concavely thinner toward the moving surface. Therefore, it is possible to suppress the change in the effective force generating surface due to the change in the shape of the foot due to the ZMP movement. Can be.
[0120]
Further, since the foot mechanism of the legged mobile robot according to the present invention is formed by laminating a plurality of materials having mutually different characteristics in the horizontal direction or the vertical direction with respect to the moving surface, the foot shape by the ZMP movement is formed. It is possible to suppress a change in the drag generating effective surface due to the change.
[0121]
Further, the foot of the legged mobile robot according to the present invention is characterized in that the friction distribution characteristics between the moving surface and the ground contact surface are determined by the central portion of the ground contact surface, the peripheral portion around the central portion, and the outermost periphery of the peripheral portion. Since different parts are used, an appropriate frictional force can be ensured, and there is no possibility of getting stuck or slipping on the moving surface.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a legged mobile robot.
FIG. 2 is a diagram schematically illustrating a configuration of a degree of freedom of a joint of the legged mobile robot.
FIG. 3 is a configuration diagram of a control system and an actuator of a legged mobile robot.
FIG. 4 is a block diagram of a control system and an actuator configuration of the legged mobile robot.
FIG. 5 is an enlarged view of a foot mechanism of the legged mobile robot.
FIG. 6 is a perspective view of a modeling foot.
FIG. 7 is a cross-sectional view of a modeling foot.
FIG. 8 is a cross-sectional view of a concrete example (first specific example) of a modeling foot;
FIG. 9 is a cross-sectional view of a second specific example.
FIG. 10 is a sectional view of a third specific example.
FIG. 11 is a cross-sectional view of a fourth specific example.
FIG. 12 is a sectional view of a fifth specific example.
FIG. 13 is a sectional view of a sixth specific example.
FIG. 14 is a sectional view of a seventh specific example.
FIG. 15 is a sectional view of an eighth specific example.
FIG. 16 is a sectional view of a ninth specific example.
FIG. 17 is a plan view of a ninth specific example.
FIG. 18 is a multi-stage characteristic diagram of deformation-hardness characteristics of a ninth specific example.
FIG. 19 is a first functional explanatory diagram showing how a structure common to each specific example functions.
FIG. 20 is a second functional explanatory view showing how a structure common to each specific example functions.
FIG. 21 is a third functional explanatory view showing how a structure common to each specific example functions.
FIG. 22 is a fourth functional explanatory view showing how a structure common to each specific example functions.
FIG. 23 is a fifth functional explanatory view showing how a structure common to each specific example functions.
FIG. 24 is a sixth functional explanatory view showing how a structure common to each specific example functions.
FIG. 25 is a seventh functional explanatory view showing how a structure common to each specific example functions.
FIG. 26 is an eighth functional explanatory view showing how a structure common to each specific example functions.
FIG. 27 is a ninth function explanatory view showing how a structure common to each specific example functions.
FIG. 28 is a characteristic diagram showing characteristics such as hardness and friction with respect to the amount of deformation in each specific example.
FIG. 29 is a characteristic diagram showing characteristics such as hardness and friction with respect to time in each specific example.
FIG. 30 is a graph showing a friction distribution characteristic between a moving surface of a foot portion and a surface in contact with the ground.
FIG. 31 is a diagram showing a foot portion formed by laminating a plurality of materials having mutually different characteristics on a concentric circle in a horizontal direction with respect to a moving surface.
FIG. 32 is a view showing a foot portion formed by laminating a plurality of materials having mutually different characteristics on an ellipse in a horizontal direction with respect to a moving surface.
FIG. 33 is a view showing a foot portion formed by laminating a plurality of materials having mutually different characteristics in a direction perpendicular to a moving surface.
FIG. 34 is a diagram of a coordinate system showing a roll axis, a pitch axis, and a yaw axis.
FIG. 35 is a diagram showing the bending that occurs in the foot of the conventional legged mobile robot.
FIG. 36 is a diagram for describing an effect-generating effective surface when the foot is in point contact with the moving surface and the road contact portion.
FIG. 37 is a diagram for describing an effect-generating effective surface when the foot contacts the moving surface and the road surface contact frame.
FIG. 38 is a diagram showing an unstable state of the foot when there is a step on the moving surface.
FIG. 39 is a diagram showing an unstable state of a foot on a carpet with long hairy feet.
FIG. 40 is a diagram showing an unstable state of a foot with respect to a moving surface having a large friction.
FIG. 41 is a diagram showing an unstable state (sliding down) of the foot when there is a step on the moving surface.
FIG. 42 is a diagram illustrating an unstable state of a foot when an obstacle is stepped on a moving surface.
FIG. 43 is a diagram showing an unstable state when a rubber material is used for a foot.
[Explanation of symbols]
1 legged mobile robot, 5R / 5L lower limb, 5 ₃ R / 5 ₃ L shank, 5 ₄ R / 5 ₄ L Ankle, 5 ₅ R / 5 ₅ L foot, 19 moving surface, 21 base, 22
Flexible part

Claims (32)

A leg-type mobile robot that is provided with a foot mechanism on a plurality of movable legs connected to a body part and moves on a moving surface using a lower limb including the plurality of movable legs and a foot mechanism,
The foot mechanism,
The body portion, a base body of hardness to oppose the force applied from the lower limbs and the moving surface,
The legged mobile robot is formed by a flexible part whose characteristics change based on the shape of the base part. 2. The base body of the foot mechanism is rigid so as not to be deformed by a torque generated by the body and the lower limbs and to a reaction force from a moving surface and to secure a supporting moment. The legged mobile robot described. When the central portion of the surface of the foot mechanism relative to the moving surface of the base portion is distinguished from its peripheral portion, the flexible portion is softer in a portion that comes into contact with the central portion of the base portion than in a portion that comes into contact with the peripheral portion. The legged mobile robot according to claim 1, wherein 2. The legged mobile robot according to claim 1, wherein the base portion of the foot mechanism reduces the thickness of the central portion on the flexible portion side in a concave shape toward a moving surface. 3. The legged mobile robot according to claim 4, wherein the flexible portion has a distribution in thickness depending on the shape of the base portion. The legged mobile robot according to claim 1, wherein an outer edge of the flexible portion on a moving surface side is a curved surface that is convex in an outer peripheral direction. The legged mobile robot according to claim 1, further comprising a contact portion that protects the flexible portion and contacts a moving surface. 8. The base body of the foot mechanism is rigid so as not to be deformed by the torque generated by the torso and the lower limbs and to the reaction force from the moving surface and to secure a supporting moment. The legged mobile robot described. When the central portion of the surface of the foot mechanism relative to the moving surface of the base portion is distinguished from its peripheral portion, the flexible portion is softer in a portion that comes into contact with the central portion of the base portion than in a portion that comes into contact with the peripheral portion. The legged mobile robot according to claim 7, wherein The legged mobile robot according to claim 7, wherein the base portion of the foot mechanism has a thickness on the flexible portion side of the central portion that is concavely thinner toward a moving surface. 11. The legged mobile robot according to claim 10, wherein the flexible portion has a thickness distribution according to the shape of the base portion. 12. The legged mobile robot according to claim 11, wherein an outer edge of the flexible portion on a moving surface side is a curved surface that is convex in an outer peripheral direction. The base unit of the foot mechanism includes an upper surface portion connected to the movable leg via an ankle portion, and a core portion located between the upper surface portion and the flexible portion. 2. The legged mobile robot according to 1. The said upper surface part and the said core part of the said base | substrate part do not deform | transform with respect to the torque which the said lower limb produces, and the reaction force from a moving surface, and are hard enough to ensure a supporting moment. 14. The legged mobile robot according to 13. When the central portion of the surface of the base portion with respect to the moving surface of the core portion is distinguished from its peripheral portion, the flexible portion is softer in a portion that comes into contact with the central portion of the core portion than in a portion that comes into contact with the peripheral portion. The legged mobile robot according to claim 13, wherein: 14. The legged mobile robot according to claim 13, wherein the core portion of the base portion has a thickness on the flexible portion side of the central portion that is concavely thinner toward a moving surface. 17. The legged mobile robot according to claim 16, wherein the flexible portion has a thickness distribution depending on a shape of a core of the base. 14. The legged mobile robot according to claim 13, further comprising a contact portion that protects the flexible portion and contacts a moving surface. A leg-type mobile robot that is provided with a foot mechanism on a plurality of movable legs connected to a body part and moves on a moving surface using a lower limb including the plurality of movable legs and a foot mechanism,
The foot mechanism,
The body portion, a base body of hardness to oppose the force applied from the lower limbs and the moving surface,
A legged mobile robot fixed to the base portion and formed by a flexible portion having a thickness on the moving surface side distributed in a concave shape at a central portion and a peripheral portion. The base body of the foot mechanism has a hardness that is not deformed by a torque generated by the body and a lower limb mechanism and a reaction force from a moving surface and that secures a supporting moment. 19. The legged mobile robot according to 19. 20. The legged mobile robot according to claim 19, wherein an outer edge of the flexible portion on a moving surface side is a curved surface that is convex in an outer peripheral direction. 20. The legged mobile robot according to claim 19, further comprising a contact portion that protects the flexible portion and contacts a moving surface. A leg-type mobile robot that is provided with a foot mechanism on a plurality of movable legs connected to a body part and moves on a moving surface using a lower limb including the plurality of movable legs and a foot mechanism,
The foot mechanism,
A legged mobile robot, wherein a plurality of materials having different characteristics are stacked and formed in a horizontal direction or a vertical direction on the moving surface. A leg-type mobile robot that is provided with a foot mechanism on a plurality of movable legs connected to a body part and moves on a moving surface using a lower limb including the plurality of movable legs and a foot mechanism,
The friction distribution characteristics of the moving surface and the ground contact surface of the foot mechanism are made different at a central portion of the ground contact surface, a peripheral portion around the central portion, and an outermost peripheral portion of the outer periphery of the peripheral portion. A legged mobile robot, characterized in that: 25. The legged mobile robot according to claim 24, wherein the frictional force distribution characteristics are large, medium, and small in the order of the peripheral portion, the central portion, and the outermost peripheral portion. A foot mechanism of a legged mobile robot provided on a side that contacts a moving surface of a plurality of movable legs connected to a body of a legged mobile robot and a ground,
Connected to the movable leg, the body portion, a rigid base portion against the force applied from the lower limb and the moving surface,
A foot mechanism of a legged mobile robot, wherein the foot mechanism is formed by a flexible part whose characteristics change based on the shape of the base part. 27. The foot of a legged mobile robot according to claim 26, further comprising a contact portion that protects the flexible portion and contacts a moving surface. A foot mechanism of a legged mobile robot provided on a side that contacts a moving surface of a plurality of movable legs connected to a body of a legged mobile robot and a ground,
The body portion, a base body of hardness to oppose the force applied from the lower limbs and the moving surface,
A foot mechanism for a legged mobile robot, comprising: a flexible portion fixed to the base portion and having a thickness on a moving surface side distributed in a concave shape at a central portion and a peripheral portion. 29. The foot of a legged mobile robot according to claim 28, further comprising a contact portion that protects the flexible portion and contacts a moving surface. A foot mechanism of a legged mobile robot provided on a side that contacts a moving surface of a plurality of movable legs connected to a body of a legged mobile robot and a ground,
A foot mechanism for a legged mobile robot, wherein a plurality of materials having different characteristics are laminated and formed in a vertical direction or a horizontal direction on the moving surface. A foot mechanism of a legged mobile robot provided on a side that contacts a moving surface of a plurality of movable legs connected to a body of a legged mobile robot and a ground,
The friction distribution characteristics of the moving surface and the ground contact surface are different between a central portion of the ground contact surface, a peripheral portion around the central portion, and an outermost peripheral portion of the peripheral portion. Leg mechanism of a legged mobile robot. 32. The foot mechanism of a legged mobile robot according to claim 31, wherein the frictional force distribution characteristics are large, medium, and small in the order of the peripheral portion, the central portion, and the outermost peripheral portion.

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