JP4110525B2 - Robot apparatus and operation control method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a robot apparatus including a base body and a plurality of movable parts connected to the base body, and an operation control method thereof, and more particularly to a legged mobile robot in which the movable part includes at least an upper limb, a lower limb, and a trunk part, and an operation thereof. It relates to a control method.
[0002]
More specifically, the present invention relates to a legged mobile robot that automatically returns after an emergency stop due to a fall or abnormality, and its operation control method, and more particularly, self-interference between moving parts and surrounding objects. The present invention relates to a legged mobile robot that autonomously recovers from an emergency stop state regardless of external interference and an operation control method thereof.
[0003]
[Prior art]
A mechanical device that uses an electrical or magnetic action to perform a movement resembling human movement is called a “robot”. It is said that the word “robot” comes from the Slavic word “ROBOTA (slave machine)”. In Japan, robots began 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.
[0004]
Recently, research and development on legged mobile robots simulating the body mechanisms and movements of biped upright walking such as humans and monkeys has progressed, and expectations for practical use are also increasing. 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.
[0005]
A legged mobile robot that reproduces a human biological mechanism and movement is particularly called a “humanoid” or “humanoid robot”. The humanoid robot can provide, for example, life support, that is, support for human activities in various situations in daily life such as a living environment.
[0006]
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.
[0007]
Articulated robots such as legged mobile robots or other robot apparatuses have a plurality of control targets such as joint angles and joint gains. In addition, the robot device operation is generally handled as an operation pattern that defines only the control values of each control object at the initial point and end point of a certain operation period, and the operation of each control object during the operation period is determined by spline interpolation or linear operation. PTP (Point to Point) control in which interpolation processing such as interpolation is performed is employed. A number of static and dynamic motion patterns are prepared in advance, and the robot device connects motion patterns that guarantee the continuity between one end point and the other initial point on the aircraft. By playing, walking, dancing, and other complicated and long-term behavior can be realized.
[0008]
Further, the legged mobile robot is generally characterized in that it is composed of a multi-link system including redundant degrees of freedom as compared to industrial robots such as manipulators and transfer robots. By taking advantage of these characteristics, it is possible to simultaneously execute a plurality of tasks such as complicated operations or movement, balance maintenance, and arm work. On the other hand, there may be an emergency stop due to an event such as losing posture stability, falling, pinching a user's finger or other foreign object, or self-interference between moving parts during operation. .
[0009]
In order for the robot to operate completely independently in an unattended environment, it is preferable that the robot can automatically recover from such an emergency stop state.
[0010]
However, when the PTP control is performed as described above, the stability of these operations is not always satisfied even if they are reproduced from the middle. Therefore, when an emergency stop occurs due to a failure such as a robot falling over, a human body being caught, or an overcurrent of the motor, it will temporarily transition to the initial state of one of the operation patterns in order to resume normal operation. It is necessary to start the operation from the initial posture.
[0011]
When actually transitioning to the initial posture, there is a possibility that unintentional self-interference of the robot itself and external interference with the surrounding environment may occur, but prepare all operations that do not cause such interference in advance. Is practically impossible.
[0012]
[Problems to be solved by the invention]
An object of the present invention is to provide an excellent legged mobile robot and an operation control method thereof that can return autonomously after an emergency stop due to a fall or abnormality.
[0013]
A further object of the present invention is to provide an excellent legged mobile robot and its operation control method capable of autonomously returning from an emergency stop state regardless of self-interference between movable parts or external interference with surrounding objects. It is to provide.
[0014]
[Means and Actions for Solving the Problems]
The present invention has been made in view of the above problems, and is a robot apparatus including a base body and a plurality of movable parts connected to the base body,
Stop means for stopping the device operation in response to occurrence of a predetermined failure;
Return means for restoring the stopped device operation without strictly solving the problem of self-interference of the robot device itself and / or external interference with the surrounding environment;
A robot apparatus comprising:
[0015]
Here, the robot apparatus is, for example, a legged mobile robot having two legs and two arms, and the plurality of movable parts may include at least an upper limb, a lower limb, and a trunk.
[0016]
When the self-interference occurs, the return means temporarily limits the torque or force generated by the joint actuator that constitutes the degree of freedom at the site where the self-interference has occurred, or restricts in advance in case the interference occurs. You may make it do.
[0017]
In such a case, even if the movable parts cause self-interference, the torque or force of the joint actuator is limited, so the return operation is continued while touching each other's surface and completed safely. Can be made.
[0018]
The return means may be operated sequentially from the tip of the movable part. For example, when returning the upper limb, the hand is operated sequentially, and when returning the lower limb, the operation is performed sequentially from the joint close to the foot. Unraveling the emergency stop state from the tip makes it difficult for the limbs to get tangled. Or in the case of a leg, for example, it is operated sequentially from a characteristic joint such as a knee joint. Alternatively, the operation is performed by shifting the start time.
[0019]
Alternatively, the return means may operate the movable part in order from the joint close to the base and limit the torque or force generated by the joint actuator that has not started to operate.
[0020]
In such a case, when driving a joint close to the base body, self-interference or entanglement may occur at a position farther from the base body, but the torque of the joint actuator is limited. The return operation can be continued and completed safely while touching the surface.
[0021]
The return means may autonomously generate an operation that does not cause interference.
[0022]
The stop means may continue to control the joint actuator of the movable part with a small torque or force even after the occurrence of a failure.
[0023]
For example, if the joint actuator is controlled with a weak torque during a fall, a certain degree of posture can be maintained at the time of landing on the floor. That is, it is possible to prevent an unexpected posture and to easily generate a subsequent return operation.
[0024]
Further, the return means can successfully complete the return operation without causing self-interference by performing the reverse operation to the operation up to the time when the failure occurs.
[0025]
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.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0027]
FIG. 1 and FIG. 2 show a state in which the “human-shaped” or “human-shaped” legged mobile robot 100 used for carrying out the present invention is viewed from the front and the rear. . As shown in the figure, a legged mobile robot 100 includes a torso, a head, left and right upper limbs, and left and right lower limbs that perform legged movement. For example, a control unit built in the torso (Not shown) controls the overall operation of the aircraft.
[0028]
Each of the left and right lower limbs is composed of a thigh, a knee joint, a shin, an ankle, and a foot, and is connected by a hip joint at the substantially lower end of the trunk. The left and right upper limbs are composed of an upper arm, an elbow joint, and a forearm, and are connected to the left and right side edges above the trunk by shoulder joints. The head is connected to the substantially uppermost center of the trunk by a neck joint.
[0029]
The control unit is equipped with a controller (main control unit) that processes the external inputs from the joint actuators and sensors (described later) that constitute the legged mobile robot 100, and a power supply circuit and other peripheral devices. It is the housing which was made. In addition, the control unit may include a communication interface and a communication device for remote operation.
[0030]
The legged mobile robot 100 configured as described above can realize bipedal walking by whole body cooperative operation control by the control unit. Such biped walking is generally performed by repeating a walking cycle divided into the following operation periods. That is,
[0031]
(1) Single leg support period with left leg lifted right leg
(2) Supporting both legs with the right foot grounded
(3) Single leg support period with right leg lifted left leg
(4) Supporting both legs with the left foot in contact with the ground
[0032]
The walking control in the legged mobile robot 100 is realized by planning a target trajectory of the lower limb in advance and correcting the planned trajectory in each of the above periods. That is, in the both-leg support period, the correction of the lower limb trajectory is stopped, and the waist height is corrected at a constant value using the total correction amount with respect to the planned trajectory. In the single leg support period, a corrected trajectory is generated so that the relative positional relationship between the corrected ankle and waist of the leg is returned to the planned trajectory.
[0033]
Starting with correction of walking motion trajectory, the attitude stability control of the aircraft is generally performed by interpolation calculation using a fifth order polynomial so that the position, speed, and acceleration for reducing the deviation from ZMP are continuous. . ZMP (Zero Moment Point) is used as a standard for determining the stability of walking. The standard for discriminating the stability by ZMP is the principle of D'Alembert that gravity and inertia force from the walking system to the road surface, and these moments balance with the floor reaction force and the floor reaction force moment as a reaction from the road surface to the walking system. based on. As a result of the dynamic reasoning, the point where the pitch axis and roll axis moments are zero on or inside the side of the support polygon (that is, the ZMP stable region) formed by the sole contact point and the road surface, that is, “ZMP (Zero Moment Point) "exists.
[0034]
FIG. 3 schematically shows a joint degree-of-freedom configuration of the legged mobile robot 100. As shown in the figure, a legged mobile robot 100 connects an upper limb including two arms and a head 1, a lower limb including two legs that realize a moving operation, and an upper limb and a lower limb. It is a structure having a plurality of limbs, which is composed of a trunk.
[0035]
A neck joint (Neck) that supports the head has three degrees of freedom: a neck joint yaw axis 1, first and second neck joint pitch axes 2 a and 2 b, and a neck joint roll axis 3.
[0036]
Each arm portion has a degree of freedom as a shoulder joint pitch axis 4 at the shoulder, a shoulder joint roll axis 5, an upper arm yaw axis 6, an elbow joint pitch axis 7 at the elbow, and a wrist ( Wrist) is composed of a wrist joint yaw axis 8 and a hand portion. The hand part is actually a multi-joint / multi-degree-of-freedom structure including a plurality of fingers.
[0037]
The trunk (Trunk) has two degrees of freedom: a trunk pitch axis 9 and a trunk roll axis 10.
[0038]
In addition, each leg constituting the lower limb includes a hip joint yaw axis 11 at the hip joint (Hip), a hip joint pitch axis 12, a hip joint roll axis 13, a knee joint pitch axis 14 at the knee (Knee), and an ankle (Ankle). ), An ankle joint pitch axis 15, an ankle joint roll axis 16, and a foot.
[0039]
However, the entertainment-type legged mobile robot 100 does not have to be equipped with all the above-mentioned degrees of freedom, or is not limited to this. It goes without saying that the degree of freedom, that is, the number of joints, can be increased or decreased as appropriate in accordance with design / manufacturing constraints and required specifications.
[0040]
Each degree of freedom of the legged mobile robot 100 as described above is actually implemented using an actuator. It is preferable that the actuator be small and light in light of demands such as eliminating an extra bulge on the appearance and approximating the shape of a human body and performing posture control on an unstable structure such as biped walking. . In the present embodiment, a small AC servo actuator of a gear direct connection type and a servo control system made into one chip and built in a motor unit is mounted (for this type of AC servo actuator, for example, this JP-A 2000-299970 already assigned to the applicant). In the present embodiment, by adopting a reduced speed gear as a direct connection gear, the passive characteristics of the drive system required for the robot 100 of a type that places importance on physical interaction with humans are obtained.
[0041]
FIG. 4 schematically shows a control system configuration of the legged mobile robot 100. As shown in the figure, the legged mobile robot 100 includes each of the mechanism units 30, 40, 50R / L, 60R / L expressing human limbs, and adaptive control for realizing a cooperative operation between the mechanism units. (Where R and L are suffixes indicating right and left, respectively, and so on).
[0042]
The entire operation of the legged mobile robot 100 is controlled by the control unit 80 in an integrated manner. The control unit 80 exchanges data and commands between a main control unit 81 configured by main circuit components (not shown) such as a CPU (Central Processing Unit) and a memory, and each component of the power supply circuit and the robot 100. The peripheral circuit 82 includes an interface (none of which is shown).
[0043]
In realizing the present invention, the installation location of the control unit 80 is not particularly limited. Although it is mounted on the trunk unit 40 in FIG. 4, it may be mounted on the head unit 30. Alternatively, the control unit 80 may be provided outside the legged mobile robot 100 so as to communicate with the body of the legged mobile robot 100 by wire or wirelessly.
[0044]
Each joint degree of freedom in the legged mobile robot 100 shown in FIG. 3 is realized by a corresponding actuator. That is, the head unit 30 includes a neck joint yaw axis actuator A that represents the neck joint yaw axis 1, the neck joint pitch axis 2, and the neck joint roll axis 3.₁, Neck joint pitch axis actuator A₂, Neck joint roll axis actuator A_ThreeIs arranged.
[0045]
The trunk unit 40 includes a trunk pitch axis actuator A that represents the trunk pitch axis 9 and the trunk roll axis 10.₉, Trunk roll axis actuator A_TenIs deployed.
[0046]
Further, the arm unit 50R / L is subdivided into an upper arm unit 51R / L, an elbow joint unit 52R / L, and a forearm unit 53R / L, but a shoulder joint pitch axis 4, a shoulder joint roll axis 5, an upper arm Shoulder joint pitch axis actuator A representing the yaw axis 6, the elbow joint pitch axis 7, and the wrist joint yaw axis 8._Four, Shoulder joint roll axis actuator A_Five, Upper arm yaw axis actuator A₆, Elbow joint pitch axis actuator A₇, Wrist joint yaw axis actuator A₈Is deployed.
[0047]
The leg unit 60R / L is subdivided into a thigh unit 61R / L, a knee unit 62R / L, and a shin unit 63R / L, but the hip joint yaw axis 11, hip joint pitch axis 12, hip joint Hip joint yaw axis actuator A representing each of roll axis 13, knee joint pitch axis 14, ankle joint pitch axis 15, and ankle joint roll axis 16.₁₁Hip joint pitch axis actuator A₁₂, Hip joint roll axis actuator A₁₃, Knee joint pitch axis actuator A₁₄, Ankle joint pitch axis actuator A₁₅, Ankle joint roll axis actuator A₁₆Is deployed.
[0048]
Actuator A used for each joint₁, A₂, A_ThreeMore preferably, it can be constituted by a small AC servo actuator (described above) of a gear direct connection type and of a type in which the servo control system is mounted on a motor unit in a single chip.
[0049]
For each mechanism unit such as the head unit 30, trunk unit 40, arm unit 50, and leg unit 60, sub-control units 35, 45, 55, and 65 for actuator drive control are provided.
[0050]
An acceleration sensor 95 and a posture sensor 96 are disposed on the trunk 40 of the body. The acceleration sensor 95 is disposed in the X, Y, and Z axial directions. By placing the acceleration sensor 95 on the waist of the airframe, the waist with a large mass manipulated variable is set as a control target point, the posture and acceleration at that position are directly measured, and posture stability control based on ZMP Can be performed.
[0051]
Further, ground check sensors 91 and 92 and acceleration sensors 93 and 94 are disposed on the leg portions 60R and 60L, respectively. The ground contact confirmation sensors 91 and 92 are configured by, for example, mounting a pressure sensor on the sole, and can detect whether the sole has landed based on the presence or absence of a floor reaction force. The acceleration sensors 93 and 94 are arranged in at least the X and Y axial directions. By disposing the acceleration sensors 93 and 94 on the left and right feet, the ZMP equation can be directly assembled with the feet closest to the ZMP position.
[0052]
When the acceleration sensor is placed only on the waist where the mass manipulated variable is large, only the waist is set as the control target point, and the foot state must be relatively calculated based on the calculation result of this control target point. It is necessary to satisfy the following conditions between the foot and the road surface.
[0053]
(1) The road surface does not move no matter what force or torque is applied.
(2) The friction coefficient with respect to translation on the road surface is sufficiently large, and no slip occurs.
[0054]
In contrast, in the present embodiment, a reaction force sensor system (such as a floor reaction force sensor) that directly measures ZMP and force is provided on a foot that is a contact portion with a road surface, and local coordinates used for control and An acceleration sensor for directly measuring the coordinates is provided. As a result, the ZMP equation can be directly assembled with the foot portion closest to the ZMP position, and more rigorous posture stabilization control that does not depend on the preconditions described above can be realized at high speed. As a result, the fuselage can be used on gravel where the road surface moves when force or torque is applied, on carpets with long bristle feet, or in residential tiles where sliding friction cannot be secured sufficiently. Can guarantee stable walking (movement).
[0055]
When an operation pattern that defines only control values of each control object at the initial point and end point of a certain operation period is input, the main control unit 80 performs spline interpolation on the operation of each control object during the operation period by PTP control. The motion is reproduced by interpolation using linear interpolation. Then, the movement patterns that guarantee the continuity between the one end point and the other initial point are connected to each other and reproduced on the body, thereby realizing walking, dancing, and other complicated and long-term actions.
[0056]
In addition, the main control unit 80 can dynamically correct the control target in response to the outputs of the sensors 91 to 93. More specifically, an adaptive control is performed on each of the sub-control units 35, 45, 55, and 65, and a whole body motion pattern in which the upper limbs, trunk, and lower limbs of the legged mobile robot 100 are driven in cooperation. Is realized.
[0057]
The whole body movement on the body of the robot 100 sets a foot movement, a ZMP (Zero Moment Point) trajectory, a trunk movement, an upper limb movement, a waist height, and the like, and instructs an operation according to these setting contents. The command is transferred to each sub-control unit 35, 45, 55, 65. And each sub-control part 35, 45 ... interprets the received command from the main control part 81, and each actuator A₁, A₂, A_ThreeA drive control signal is output to. Here, “ZMP” refers to a point on the floor where the moment due to floor reaction force during walking is zero, and “ZMP trajectory” refers to, for example, ZMP during the walking motion period of the robot 100. Means the trajectory that moves (see above).
[0058]
The legged mobile robot 100 according to this embodiment has a center of gravity set at the waist position, is an important control target point for posture stability control, and constitutes a “base” of the apparatus.
[0059]
When the robot stops suddenly due to a fall, pinching of the human body, an overcurrent of the motor, etc., in order to resume normal operation, the robot temporarily moves to the initial state of one of the operation patterns, It is necessary to start operation from the initial posture. When actually transitioning to the initial posture, there is a possibility that unintentional self-interference of the robot itself and external interference with the surrounding environment may occur, but prepare all operations that do not cause such interference in advance. Is practically impossible.
[0060]
For this reason, the present inventors consider that any of the following methods is necessary for the legged mobile robot to automatically return from the emergency stop state. That is,
[0061]
(A) A method for continuing operation even when interference occurs without solving a strict interference problem
(B) A method for generating a non-interfering operation without solving a strict interference problem
(C) A method for generating a non-interfering operation while solving a strict interference problem
[0062]
Hereinafter, several methods for automatically returning the legged mobile robot from the emergency stop state will be described with reference to the drawings.
[0063]
A. How to recover without solving exact interference problems
When the autonomously generated motion is realized by controlling each joint, unintended self-interference of the robot itself and external interference with the surrounding environment may occur. In this case, several methods for completing the return operation without solving a strict interference problem are listed below.
[0064]
A-1. Weak joint actuator
When self-interference occurs, the torque or force generated by the joint actuator is temporarily limited. Or it restrict | limits beforehand in case interference arises.
[0065]
5 to 8 show how the left arm of the legged mobile robot in the upright posture is returned from the emergency stop state.
[0066]
When the left forearm is lowered in the state where the left forearm is on the right forearm in front of the torso as shown in FIG. 5, self-interference with the right forearm is caused as shown in FIG.
[0067]
In this example, the torque or force of the joint actuator related to all or return is temporarily limited, so that the return operation is continued while the left forearm is in contact with the surface of the right forearm (FIG. 7). The return operation can be completed successfully (FIG. 8).
[0068]
A-2. Operate sequentially from the tip of the movable part
When the return operation is performed by PTP control, the operation is sequentially performed from the tip of the movable part. For example, when returning the upper limb, the hand is operated sequentially, and when returning the lower limb, the operation is performed sequentially from the joint close to the foot. Unraveling the emergency stop state from the tip makes it difficult for the limbs to get tangled. Or in the case of a leg, for example, it is operated sequentially from a characteristic joint such as a knee joint. Alternatively, the operation is performed by shifting the start time.
[0069]
9 to 12 show an operation in which the legged mobile robot 100 returns in order from the side closer to the foot tip in the above-ground posture in which the left leg is laid under the right leg.
[0070]
When the legged mobile robot 100 is in an on-floor posture in which the left leg is laid under the right leg, first, the return movement is started from the ankle joint (see FIG. 9), and then the knee joint roll axis of both legs is set. Drive back (see FIG. 10) and drive the hip joints of both legs to release the interference state of both legs (see FIG. 11), thereby returning the legs without entanglement. The operation can be successfully completed (see FIG. 12).
[0071]
A-3. Operate sequentially from the base of moving parts
When performing PTP control, the joints are operated in order from the joint close to the base link. In this case, the limbs are prevented from being entangled by limiting the torque or force generated by the joint actuator that has not started to move.
[0072]
FIGS. 13 to 16 show a state in which the legged mobile robot 100 returns in order from the side closer to the body in the above-ground posture in which the left leg is laid under the right leg.
[0073]
When the legged mobile robot 100 is on the floor with the left leg under the right leg, the legged mobile robot 100 first starts a return operation from the hip joint (see FIG. 13), and then the knee joint (see FIG. 14). And the return operation in the order of the ankle joint (see FIG. 15).
[0074]
In this case, when the hip joint is restored, self-interference between both legs occurs, but the torque of the joint actuator that has not started the movement below the knee joint is limited, so the left leg is in contact with the right leg surface, The return operation can be successfully completed without being entangled (see FIG. 16).
[0075]
Since the torque generated by the actuator during the return operation increases, the methods A-1, A-2, and A-3 described above are selectively applied while detecting self-interference and external interference. The return operation may be performed.
[0076]
B. A method for autonomously generating motion without interference without solving exact interference problemsIn a legged mobile robot, several methods for autonomously generating a motion without interference without solving a strict interference problem are listed below.
[0077]
B-1. Continue control with small torque or force
Even after the occurrence of a failure, the torque or force generated by the joint actuator is not set to zero, and control is continued with a small torque or force. As a result, an unexpected posture can be prevented, and the subsequent return operation can be easily generated.
[0078]
17 to 18 show the behavior when the legged mobile robot 100 sets the generated torque of the joint actuator to 0 after the occurrence of the failure. Assume that the legged mobile robot 100 falls from the upright posture shown in FIG. 17 due to some failure. At this time, if the generated torque is set to 0, as shown in FIG.
[0079]
The unexpected posture mentioned here is a posture that was not assumed when creating (programming) the motion pattern. For example, in PTP control, it means that there are few motion patterns that match the initial point. To do. For this reason, it is difficult to return.
[0080]
On the other hand, FIGS. 19 to 21 show behaviors when the legged mobile robot 100 controls the joint actuator with a weak torque after the occurrence of a failure. Assume that the legged mobile robot 100 falls from an upright posture shown in FIG. At this time, if the joint actuator is controlled with a weak torque, a certain degree of posture can be maintained at the time of landing on the floor, as shown in FIG.
[0081]
Here, a certain degree of posture is a posture that can be assumed when creating (programming) motion patterns. For example, in PTP control, there are relatively many motion patterns that match as initial points. It means to do. For this reason, the return is facilitated.
[0082]
B-2. Go back to the time of failure
In order to return from the posture at the time of the failure, an operation reverse to the operation up to the time when the failure occurs is performed. For example, the main control unit records a log of operation patterns that are sequentially input in the PTP control. By re-inputting in the reverse order of recording, the operation reverse to the operation up to the time when the failure occurred is recorded. The action can be played back.
[0083]
22 to 24 show how the left arm of the legged mobile robot in the upright posture tries to return from the emergency stop state.
[0084]
In a normal operating state where the left forearm is above the right forearm in front of the torso (see Figure 22), a failure occurred while attempting to lower the left forearm, and the aircraft was brought to an emergency stop (See FIG. 23). At this time, since the left and right forearms are close to each other, if the return operation is mistaken, the left and right forearms self-interfere (see FIG. 24), and a secondary failure occurs, which is recovered. Will not stick.
[0085]
On the other hand, FIGS. 25 to 28 show a state in which when a failure occurs in the same manner as described above, the operation is restored by performing an operation reverse to the operation up to the time of occurrence of the failure.
[0086]
In a normal operating state where the left forearm is above the right forearm in front of the torso (see Figure 25) (See FIG. 26). At this time, by performing the movement of the left forearm in the opposite direction until the time of the failure (see FIG. 27), the return operation can be completed successfully without causing self-interference (see FIG. 28). thing).
[0087]
B-3. Prepare the operation from the return posture to the initial normal posture.
When PTP control is performed, these operations do not always satisfy the stability even if they are reproduced from the middle. Therefore, when an emergency stop occurs due to a failure such as a robot falling over, a human body being caught, or an overcurrent of the motor, it will temporarily transition to the initial state of one of the operation patterns in order to resume normal operation. It is necessary to start the operation from the initial posture.
[0088]
Therefore, by preparing a plurality of return postures and preparing an operation from the return posture to the normally used initial posture, it is possible to smoothly shift to the initial posture of a desired operation pattern.
[0089]
At this time, a plurality of return postures are prepared so that all postures that the robot can take can be changed to any return posture by PTP control. Similarly, a plurality of return postures are prepared, and the operation up to the initial posture for normal use is completed via these postures (see FIG. 29).
[0090]
B-4. Aircraft design considering self-interference
It is designed so that the joint movable range and joint freedom degree arrangement of the robot joint are not interfered by PTP control or the like.
[0091]
C. A method to autonomously generate motion without interference by solving exact interference problem
The legged mobile robot autonomously generates and returns an action that does not cause interference by solving a strict interference problem.
[0092]
[Supplement]
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 embodiments without departing from the gist of the present invention.
[0093]
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.
[0094]
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 section described at the beginning should be considered.
[0095]
【The invention's effect】
As described above in detail, according to the present invention, an excellent legged mobile robot capable of autonomously returning from an emergency stop state regardless of self-interference between movable parts or external interference with surrounding objects. And an operation control method thereof.
[Brief description of the drawings]
FIG. 1 is a view showing a state in which a legged mobile robot used for carrying out the present invention is viewed from the front.
FIG. 2 is a view showing a state in which a legged mobile robot used for carrying out the present invention is viewed from the rear.
FIG. 3 is a diagram schematically illustrating a joint degree-of-freedom configuration included in a legged mobile robot.
4 is a diagram schematically showing a control system configuration of a legged mobile robot 100. FIG.
FIG. 5 is a diagram for explaining an operation in which the legged mobile robot 100 recovers from an emergency stop state by de-energizing a joint actuator.
FIG. 6 is a diagram for explaining an operation in which the legged mobile robot 100 recovers from an emergency stop state by de-energizing a joint actuator.
FIG. 7 is a diagram for explaining an operation in which the legged mobile robot 100 recovers from an emergency stop state by de-energizing a joint actuator.
FIG. 8 is a diagram for explaining an operation in which the legged mobile robot 100 recovers from an emergency stop state by de-energizing a joint actuator.
FIG. 9 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the foot tip in the above-ground posture in which the left leg is laid under the right leg.
FIG. 10 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the foot tip in the above-ground posture in which the left leg is laid under the right leg.
FIG. 11 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the foot tip in the above-ground posture in which the left leg is laid under the right leg.
FIG. 12 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the foot tip in the above-ground posture in which the left leg is laid under the right leg.
FIG. 13 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the trunk in an on-floor posture in which the left leg is laid under the right leg.
FIG. 14 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the trunk in the above-ground posture in which the left leg is laid under the right leg.
FIG. 15 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the trunk in the above-ground posture in which the left leg is laid under the right leg.
FIG. 16 is a diagram for explaining an operation in which the legged mobile robot 100 returns in order from the side closer to the trunk in the above-ground posture in which the left leg is laid under the right leg.
FIG. 17 is a diagram for explaining the behavior when the legged mobile robot 100 sets the generated torque of the joint actuator to 0 after the occurrence of a fault.
FIG. 18 is a diagram for explaining the behavior when the legged mobile robot 100 sets the generated torque of the joint actuator to 0 after the occurrence of a fault.
FIG. 19 is a diagram for explaining the behavior when the legged mobile robot 100 controls the joint actuator with a weak torque after the occurrence of a fault.
FIG. 20 is a diagram for explaining the behavior when the legged mobile robot 100 controls the joint actuator with a weak torque after a failure occurs.
FIG. 21 is a diagram for explaining the behavior when the legged mobile robot 100 controls the joint actuator with a weak torque after the occurrence of a fault.
FIG. 22 is a diagram showing a state where an attempt is made to return the left arm of the legged mobile robot in an upright posture from an emergency stop state.
FIG. 23 is a diagram showing a state where an attempt is made to return the left arm of the legged mobile robot in an upright posture from an emergency stop state.
FIG. 24 is a diagram showing a state where an attempt is made to return the left arm of the legged mobile robot in an upright posture from an emergency stop state.
FIG. 25 is a diagram for explaining a method of returning from an emergency stop state by performing an operation reverse to the operation up to the time of occurrence of the failure of the legged mobile robot.
FIG. 26 is a diagram for explaining a method of returning from an emergency stop state by performing an operation reverse to the operation up to the time when a failure occurs in the legged mobile robot.
FIG. 27 is a diagram for explaining a method of returning from an emergency stop state by performing an operation reverse to the operation performed by the legged mobile robot until a failure occurs.
FIG. 28 is a diagram for explaining a method of returning from an emergency stop state by performing an operation reverse to the operation up to the time of occurrence of the failure of the legged mobile robot.
FIG. 29 is a diagram for explaining a method of preparing an operation from a returning posture to an initial posture for normal use.
[Explanation of symbols]
1 ... Neck joint yaw axis
2A ... 1st neck joint pitch axis
2B ... Second neck joint (head) pitch axis
3 ... Neck joint roll axis
4. Shoulder joint pitch axis
5 ... Shoulder joint roll axis
6 ... Upper arm yaw axis
7. Elbow joint pitch axis
8 ... wrist joint yaw axis
9 ... trunk pitch axis
10 ... trunk roll axis
11 ... Hip joint yaw axis
12 ... Hip pitch axis
13 ... Hip roll axis
14 ... Knee joint pitch axis
15 ... Ankle joint pitch axis
16 ... Ankle joint roll axis
30 ... head unit, 40 ... trunk unit
50 ... arm unit, 51 ... upper arm unit
52 ... Elbow joint unit, 53 ... Forearm unit
60 ... Leg unit, 61 ... Thigh unit
62 ... knee joint unit, 63 ... shin unit
80 ... control unit, 81 ... main control unit
82. Peripheral circuit
91, 92 ... Grounding confirmation sensor
93, 94 ... acceleration sensor
95 ... Attitude sensor
96 ... Acceleration sensor
100: Legged mobile robot

Claims (12)

A robot apparatus comprising a base and a plurality of movable parts directly connected to the base,
Stop means for stopping the device operation in response to occurrence of a predetermined failure;
Temporarily limit the torque or force generated by the joint actuator that constitutes the degree of freedom in the part where self-interference occurs when self-interference occurs when returning the device operation after the operation is stopped by the stop means. Including a return means for restricting in advance and recovering the operation of the stopped apparatus , in case of interference .
The return means is sequentially operated from the tip of the movable part.
A robot apparatus characterized by that. A robot apparatus comprising a base and a plurality of movable parts directly connected to the base,
Stop means for stopping the device operation in response to occurrence of a predetermined failure;
Temporarily limit the torque or force generated by the joint actuator that constitutes the degree of freedom in the part where the self-interference occurs when self-interference occurs when returning the device operation after the operation is stopped by the stop means. Including a return means for restricting in advance in case of interference or returning the stopped device operation,
The return means operates the movable part in order from a joint close to the base body, and limits a torque or force generated by a joint actuator that has not started to operate,
A robot apparatus characterized by that. The plurality of movable parts include at least an upper limb, a lower limb, and a trunk.
The robot apparatus according to claim 1, wherein the robot apparatus is characterized. The return means autonomously generates an operation that does not cause interference,
The robot apparatus according to claim 1, wherein the robot apparatus is characterized. The stop means continues to control the joint actuator of the movable part with a small torque or force even after the occurrence of a failure,
The robot apparatus according to claim 4, wherein: The return means performs an operation opposite to the operation up to the time when the failure occurs.
The robot apparatus according to claim 4, wherein: An operation control method for a robot apparatus having a base and a plurality of movable parts directly connected to the base,
A stop step for stopping the device operation in response to occurrence of a predetermined failure;
Temporarily limit the torque or force generated by the joint actuator that constitutes the degree of freedom in the part where the self-interference occurs when self-interference occurs when returning the device operation after the operation is stopped by the stop step. Or including a return step for returning the stopped device operation by limiting in advance in case of interference.
In the return step, the movable part is sequentially operated from the tip.
An operation control method for a robot apparatus. An operation control method for a robot apparatus having a base and a plurality of movable parts directly connected to the base,
A stop step for stopping the device operation in response to occurrence of a predetermined failure;
Temporarily limit the torque or force generated by the joint actuator that constitutes the degree of freedom in the part where the self-interference occurs when self-interference occurs when returning the device operation after the operation is stopped by the stop step. In advance in case of interference or interference. Limitedly, a return step for returning the stopped device operation,
In the return step, the movable part is operated in order from the joint close to the base body, and the torque or force generated by the joint actuator that has not started to operate is limited.
An operation control method for a robot apparatus. The plurality of movable parts include at least an upper limb, a lower limb, and a trunk.
9. The operation control method for a robot apparatus according to claim 7 or 8, wherein In the return step, an operation that does not cause interference autonomously is generated.
9. The operation control method for a robot apparatus according to claim 7 or 8, wherein In the stop step, the joint actuator of the movable part continues to be controlled with a small torque or force even after the occurrence of a failure.
The operation control method of the robot apparatus according to claim 10. In the return step, an operation reverse to the operation up to the time of occurrence of the failure is performed.
The operation control method of the robot apparatus according to claim 10.

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