WO2021009991A1

WO2021009991A1 - Robot device and method for controlling same

Info

Publication number: WO2021009991A1
Application number: PCT/JP2020/018242
Authority: WO
Inventors: 将也木下; 康久神川; 憲明高杉; 川浪　康範
Original assignee: ソニー株式会社
Priority date: 2019-07-12
Filing date: 2020-04-30
Publication date: 2021-01-21
Also published as: JP2021013992A

Abstract

Provided is a robot device that comprises a plurality of legs, and avoids potential malfunctions caused by failure of some of the legs.　The robot device is provided with: a plurality of legs; a detector for detecting whether failure has occurred in each of the plurality of legs; and a controller for controlling operation in response to failure being detected in one of the plurality of legs by the detector. The controller controls the device so as to retreat to a safe location by walking using the functioning legs, and so that the maximum supporting polygon is formed by the functioning legs during this process. The controller also notifies the external device of information pertaining to the leg in which failure was detected.

Description

Robot device and its control method

The technique disclosed in this specification relates to a robot device having a plurality of legs and a control method thereof.

In recent years, the development of leg-type robots has been promoted. In general, a legged robot is capable of walking by alternately switching between standing and attracting a plurality of legs. Compared to other types of mobile robots such as wheel type robots, it has the advantage of being able to move on both leveled and rough terrain. Therefore, the legged robot can be used not only in a limited space such as in a factory, but also in any free space such as a living space where humans live and a space where it is difficult or dangerous for humans to work (for example, in a radiation environment). It is expected to be used.

On the other hand, since the legs have a complicated multi-link structure, there is a concern that one of the multiple legs may break down while exploring the free space.

For example, in a walking robot that can walk with four legs and can work with arms, a motor consisting of two motors incorporated coaxially is used for joint drive, and one motor cannot operate due to disconnection or other reasons. A proposal has been made for a walking robot that can continue walking by supplying a current to the other motor even in the case of (see Patent Document 1). However, if two motors are arranged for each joint and the same joint drive method is adopted for all legs, the total number of motors mounted on the entire walking robot will increase, and the weight of the main body will increase accordingly. There is concern that the production cost will also increase. In addition, if a part other than the motor is damaged and the leg becomes inoperable, it can be dealt with.

Also, any of the multiple legs is configured to be placed anywhere around the body of the pedestrian body and is actuated by repositioning with any leg that is functioning in place of the failed leg. A proposal has been made for a robot that can change the walking mode when the number of robots is reduced (see Patent Document 2). Since this robot needs to be equipped with more legs in case the number of operating legs decreases due to a failure, the number of motors and links increases, the weight of the robot increases, and the manufacturing cost also increases. There is concern that it will become.

Japanese Unexamined Patent Publication No. 2004-314216 Japanese Unexamined Patent Publication No. 3-92275

An object of the technique disclosed in this specification is to provide a robot device having a plurality of legs and a control method thereof.

The technology disclosed in the present specification has been made in consideration of the above-mentioned problems, and the first aspect thereof is.
With multiple legs,
A detection unit that detects whether or not each of the plurality of legs is out of order,
A control unit that controls the operation according to the detection unit detecting a failure in any of the plurality of legs.
It is a robot device equipped with.

In the robot device according to the first aspect, the control unit controls the robot device to evacuate to the safe place by walking using the non-faulty leg, and at that time, the control unit is composed of the non-faulty leg. Control so that the supported polygon to be supported is maximized. In addition, the external device is notified of information regarding the leg in which the failure is detected.

In addition, the second aspect of the technology disclosed herein is:
It is a control method for a robot device equipped with multiple legs.
A step of detecting whether or not each of the plurality of legs is defective,
A step of performing an action according to the detection of a failure in any of the plurality of legs, and
It is a control method of a robot device having.

According to the technique disclosed in the present specification, it is possible to provide a robot device having a plurality of legs and avoiding obstacles that may occur due to a failure of some legs and a control method thereof.

It should be noted that the effects described in the present specification are merely examples, and the effects brought about by the techniques disclosed in the present specification are not limited thereto. In addition, the technique disclosed in the present specification may exert additional effects in addition to the above effects.

Still other objectives, features and advantages of the techniques disclosed herein will be clarified by more detailed description based on embodiments and accompanying drawings described below.

FIG. 1 is a diagram showing an example of a degree of freedom configuration of the robot device 100. FIG. 2 is a diagram showing a configuration example of an electric system of the robot device 100. FIG. 3 is a diagram showing a support polygon (when a failure occurs) of the robot device 100. FIG. 4 is a diagram showing a support polygon (after the change in walking form) of the robot device 100. FIG. 5 is a diagram for explaining a mechanism for changing the walking mode of the robot device 100. FIG. 6 is a diagram for explaining a mechanism for changing the walking mode of the robot device 100. FIG. 7 is a diagram showing a gait example of the robot device 100. FIG. 8 is a diagram showing a gait example of the robot device 100 when the broken leg is moved to a position where it does not get in the way. FIG. 9 is a diagram showing an example of the gait of the robot device 100 when the broken leg is moved to a position where it does not get in the way. FIG. 10 is a diagram showing how the robot device 100 walks according to the remaining capacity of the failed leg. FIG. 11 is a diagram showing support polygons when a part of the legs of the robot device 100 fails. FIG. 12 is a diagram showing a support polygon when the walking mode is changed due to a failure of a part of the legs of the robot device 100. FIG. 13 is a diagram showing a support polygon when a part of the legs of the robot device 100 fails. FIG. 14 is a diagram showing a support polygon when the walking mode is changed due to a failure of a part of the legs of the robot device 100. FIG. 15 is a flowchart showing an operation procedure executed by the robot device 100 when a part of the legs breaks down.

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

A. Device Configuration FIG. 1 schematically shows an example of a degree of freedom configuration of a robot device 100 having a plurality of legs to which the technique disclosed in the present specification is applied. The illustrated robot device 100 includes a body portion 101 and four

movable legs

110, 120, 130, and 140 connected to the four corners of the body portion 101, respectively. Here, the leg 110 is the left front leg (LF), the leg 120 is the right front leg (RF), the leg 130 is the left hind leg (LR), and the leg 140 is the right hind leg (RR). The robot device 100 can walk by operating the

legs

110, 120, 130, and 140 synchronously (while alternately switching between the stance and the swing leg). Further, it is assumed that the robot device 100 carries the load loaded on the body portion 101 by loading the load on the body portion 101.

The leg 110 includes two

links

111 and 112, and a joint portion 113 connecting the link 111 and the link 112. The other end (lower end) of the link 111 corresponds to the sole of the foot and is installed on the floor. Further, the upper end of the link 112 is attached to the body portion 101 via the joint portion 114. The joint portion 113 has a degree of freedom of rotation around the pitch axis, and the link 111 can be driven around the pitch axis with respect to the link 112 by an actuator (not shown) such as a pitch axis rotation motor. Further, the joint portion 114 has at least a degree of freedom of rotation around the pitch axis and the roll axis, and the link 112 is provided around the pitch axis and the roll axis with respect to the body portion 101 by an actuator (not shown) such as a pitch axis rotation motor. Can be driven to. The link 112 is also referred to as a first link, and the link 111 is also referred to as a second link in order of proximity to the body portion 101. Further, the joint portion 114 is also referred to as a first joint, and the joint portion 113 is also referred to as a second joint in the order of proximity to the body portion 101.

Further, the leg 120 is provided with two

links

121 and 122 and a joint portion 123 connecting the link 121 and the link 122. The other end (lower end) of the link 121 corresponds to the sole of the foot and is installed on the floor surface. Further, the upper end of the link 122 is attached to the body portion 101 via the joint portion 124. The joint portion 123 has a degree of freedom of rotation around the pitch axis, and the link 121 can be driven around the pitch axis with respect to the link 122 by an actuator (not shown) such as a pitch axis rotation motor. Further, the joint portion 124 has at least a degree of freedom of rotation around the pitch axis and the roll axis, and the link 122 is provided around the pitch axis and the roll axis with respect to the body portion 101 by an actuator (not shown) such as a pitch axis rotation motor. Can be driven to. The link 122 is also referred to as a first link, and the link 121 is also referred to as a second link in order of proximity to the body portion 101. Further, the joint portion 124 is also referred to as a first joint, and the joint portion 123 is also referred to as a second joint in the order of proximity to the body portion 101.

Further, the leg 130 includes two

links

131 and 132, and a joint portion 133 that connects the link 131 and the link 132. The other end (lower end) of the link 131 corresponds to the sole of the foot and is installed on the floor. Further, the upper end of the link 132 is attached to the body portion 101 via the joint portion 134. The joint portion 133 has a degree of freedom of rotation around the pitch axis, and the link 131 can be driven around the pitch axis with respect to the link 132 by an actuator (not shown) such as a pitch axis rotation motor. Further, the joint portion 134 has at least a degree of freedom of rotation around the pitch axis and the roll axis, and the link 132 is provided around the pitch axis and the roll axis with respect to the body portion 101 by an actuator (not shown) such as a pitch axis rotation motor. Can be driven to. The link 132 is also referred to as a first link, and the link 131 is also referred to as a second link in order of proximity to the body portion 101. Further, the joint portion 134 will be referred to as the first joint, and the joint portion 133 will be referred to as the second joint in the order of proximity to the body portion 101.

Further, the leg 140 is provided with two

links

141 and 142 and a joint portion 143 connecting between the link 141 and the link 142. The other end (lower end) of the link 141 corresponds to the sole of the foot and is installed on the floor. Further, the upper end of the link 142 is attached to the body portion 101 via the joint portion 144. The joint portion 143 has a degree of freedom of rotation around the pitch axis, and the link 141 can be driven around the pitch axis with respect to the link 142 by an actuator (not shown) such as a pitch axis rotation motor. Further, the joint portion 144 has at least a degree of freedom of rotation around the pitch axis and the roll axis, and the link 142 is provided around the pitch axis and the roll axis with respect to the body portion 101 by an actuator (not shown) such as a pitch axis rotation motor. Can be driven to. The link 142 is also referred to as a first link, and the link 141 is also referred to as a second link in order of proximity to the body portion 101. Further, the joint portion 144 is also referred to as a first joint, and the joint portion 143 is also referred to as a second joint in the order of proximity to the body portion 101.

Although the robot device 100 shown in the figure is composed of four legs, it should be understood that the technology disclosed in the present specification can be applied even if the robot device 100 is equipped with two legs, three legs, or 55 legs or more.

Further, although omitted in FIG. 1, the body portion 101 may be equipped with a head equipped with a camera, a speaker, or the like, an arm for work, or the like.

FIG. 2 shows a configuration example of the electrical system of the robot device 100.

In the robot device 100, as an external sensor unit 210,

cameras

211L and 211R that function as the left and right "eyes" of the robot device 100, a microphone 212 that functions as an "ear", a touch sensor 213, and the like are arranged at predetermined positions, respectively. ing. As the

cameras

211L and 211R, for example, cameras composed of image pickup elements such as CMOS (Complementary Metal Oxide Semiconductor) and CCD (Charge Coupled Device) are used.

Although not shown, the external sensor unit 210 may further include other sensors. For example, the external sensor unit 210 includes a sole sensor that measures the floor reaction force acting on the soles of the

legs

110, 120, 130, and 140. Each sole sensor is composed of, for example, a 6DOF (Degree Of Freedom) force sensor or the like.

Further, the external sensor unit 210 may include a sensor capable of measuring or estimating the direction and distance of a predetermined target such as a LIDAR (Laser Imaging Detection and Ranking), a TOF (Time OF Light) sensor, and a laser range sensor. Further, the external sensor unit 210 may include a GPS (Global Positioning System) sensor, an infrared sensor, a temperature sensor, a humidity sensor, an illuminance sensor, and the like.

Further, in the robot device 100, a speaker 221 and a display unit 222 are arranged at predetermined positions as output units. The speaker 221 functions to output voice and provide voice guidance, for example. Further, the display unit 222 displays the state of the robot device 100 and the response to the user.

In the control unit 230, an internal sensor unit 233 including a main control unit 231, a battery 232, a battery sensor 233A, an acceleration sensor 233B, etc., an external memory 234, and a communication unit 235 are arranged.

The

cameras

211L and 211R of the external sensor unit 210 image the surrounding situation and send the obtained image signal S1A to the main control unit 231. The microphone 212 collects voice input from the user and sends the obtained voice signal S1B to the main control unit 231. The input voice given to the robot device 100 by the user includes an activation word and various command voices (voice commands) such as "walk", "turn right", "hurry", and "stop". Although only one microphone 82 is drawn in FIG. 2, two or more microphones may be provided like the left and right ears to estimate the sound source direction.

Further, the touch sensor 213 of 210 of the external sensor unit is laid, for example, on the mounting surface of the body portion 101, detects the pressure received at the place where the luggage is placed, and outputs the detection result to the pressure detection signal. It is sent to the main control unit 231 as S1C.

The battery sensor 233A of the internal sensor unit 233 detects the remaining energy of the battery 232 at predetermined intervals, and sends the detection result as the battery remaining amount detection signal S2A to the main control unit 231.

The acceleration sensor 233B detects acceleration in three axial directions (x (roll) axis, y (pitch) axis, and z (yaw) axis) at predetermined cycles for the movement of the robot device 100, and obtains the detection result. , Is sent to the main control unit 231 as an acceleration detection signal S2B. The acceleration sensor 233B may be, for example, an IMU (Inertial Measurement Unit) equipped with a three-axis gyro and a three-direction acceleration sensor. The IMU can be used to measure the angle and acceleration of the robot device 100 body or body 101.

The external memory 234 stores programs, data, control parameters, etc., and supplies the programs and data to the memory 231A built in the main control unit 231 as needed. Further, the external memory 234 stores data and the like received from the memory 231A in the main control unit 231. The external memory 234 may be configured as a cartridge type memory card such as an SD card, and may be detachable from the robot device 100 main body (or the control unit 230).

The communication unit 235 performs data communication with the outside based on a communication method such as Wi-Fi (registered trademark) or LTE (Long Term Evolution). For example, a program such as an application executed by the main control unit 231 and data required for executing the program can be acquired from the outside via the communication unit 235.

The main control unit 231 has a built-in memory 231A. The memory 231A stores programs and data, and the main control unit 231 performs various processes by executing the programs stored in the memory 231A. That is, the main control unit 231 includes the image signal S1A, the audio signal S1B, and the pressure detection signal S1C (hereinafter, these are collectively supplied) from the

cameras

211L and 211R of the external sensor unit 210, the microphone 212, and the touch sensor 213, respectively. The external sensor signal S1 and the battery remaining amount detection signal S2A and the acceleration detection signal S2B (hereinafter, these are collectively referred to as an internal sensor signal) supplied from the battery sensor 233A and the acceleration sensor 233B of the internal sensor unit 233, respectively. Based on (referred to as S2), it is determined whether or not the surrounding and internal conditions of the robot device 100, a command from the user, or an action from the user. Information on the weight and the position of the center of gravity of the robot device 100 (however, no luggage is placed on the body 101) may be stored in the memory 231A in advance.

Then, the main control unit 231 determines the surrounding and internal conditions of the robot device 100, the command from the user, or the presence / absence of the action from the user, and the control program stored in advance in the internal memory 231A, or a control program thereof. Based on various control parameters stored in the external memory 234 loaded at the time, the action of the robot device 100 and the expression action to be activated for the user are determined, and a control command based on the decision result is generated. Then, it is sent to each sub-control unit 241, 242, ....

The sub-control units 241 and 242, ... Are each in charge of operating control of each subsystem in the robot device 100, and drive the subsystems based on the control commands supplied from the main control unit 231. The

movable legs

110, 120, 130, and 140 described above correspond to subsystems, and are driven and controlled by sub-control units 241, 242, 243, and 244, respectively. Specifically, the sub control units 241, 242, 243, and 244 drive control of the

joint portions

113, 114, 123, 124, 133, 134, 143, and 144, and set the initial displacement amount of the load compensation mechanism (described later). And so on.

B. Operation at the time of leg failure The robot device 100 walks by synchronously operating the

legs

110, 120, 130, and 140 (while switching between the standing leg and the swing leg alternately). At that time, the toes of the

legs

110, 120, 130, and 140 repeatedly land on the floor, that is, collide with the floor surface, so that a failure is likely to occur. If any of the

legs

110, 120, 130, or 140 fails, it becomes difficult to walk with only the remaining normal legs, the posture becomes unstable, and there is a risk of colliding with the road surface or surrounding people or objects due to a fall. ..

The robot device 100 that has become difficult to move cannot be restored without human intervention. Further, if the robot device 100, which is difficult to move, is left as it is, it becomes a new obstacle to humans and other robots sharing the space, which may cause serious problems such as secondary damage. Specific examples caused by the failed robot device 100 include the following.

(Example 1) There is a robot device 100 stopped in the middle of the road, which hinders the following moving body. In addition, it induces secondary damage such as a rear-end collision between the stopped robot device 100 and another moving body.

(Example 2) Even if the robot device 100 stops due to a failure while working in a space where it is difficult for humans to invade, such as in a radiation environment, it is extremely difficult for humans to go to repair. If the stopped robot device 100 blocks the passage, the difficulty of the work of the other moving body during work and the other moving body toward recovery will be raised.

When the work by the robot device 100 is started, if the preliminary failure detection is not performed or the detection level is low, there is a high possibility that the robot device 100 will stop due to a leg failure during the work. However, even if the level of detection is increased, it is not possible to completely prevent leg failure during work.

Also, the robot device 100 is not designed so that it can operate with only the remaining available legs after some legs break down during work. For this reason, if a part of the legs breaks down during the work, the walking motion becomes unstable only with the remaining legs, and it is difficult to completely perform the subsequent work. If it is designed so that it can operate with the available legs even if some of the legs break down (see Patent Document 2), the device weight and the device cost increase.

Therefore, in the present specification, the operation method for minimizing the risk of secondary damage when at least a part of the legs of the robot device 100 breaks down is proposed below.

B-1. Operation example when a leg breaks down 1
One of the features of the operation method proposed in the present specification is that the robot device 100 is changed to a walking mode using only the remaining normal legs when at least a part of the legs breaks down, and is a safe place. The point is to evacuate to and reduce the risk of secondary damage.

Evacuation to a safe place is realized, for example, by moving the robot device 100 to the end of the passage and deviating from the path of another moving body using the same passage. In addition, when a leg failure occurs near a curve at a right angle to the passage, it generally passes through the inside of the curve, so that the outside of the curve is a safe evacuation site.

Then, when the robot device 100 evacuates to a safe place, the robot device 100 is changed to a form in which only normal legs are used so that the supporting polygon is maximized, and an attempt is made to continue the walking motion. The support polygon is a polygon that convexly wraps the ground planes of all the support legs. For example, it is a standard for determining stability that the ZMP (Zero Moment Point) or the center of gravity of the mass is housed in the support polygon. If some of the legs break down and become unusable, the posture of the robot device 100 becomes unstable, but the remaining available legs increase the support polygon to stabilize it.

In addition, the robot device 100 stabilizes its posture while retracting to a safe place by changing the walking form with the remaining available legs so that the margin in the traveling direction of the geometric center of gravity of the supporting polygon is maximized. It is possible to prevent the fall.

FIG. 3 is composed of the remaining left front leg 110 (LF), left rear leg 130 (LR), and right rear leg 140 (RR) when the right front leg 120 (RF) of the robot device 100 fails. The support polygon 300 is illustrated. At this time, when the robot device 100 has the forward direction as the traveling direction, the margin in the traveling direction of the geometric center of gravity of the support polygon 300 is as shown in Reference No. 301.

On the other hand, in FIG. 4, walking by the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR) so that the margin in the traveling direction of the geometric center of gravity of the supporting polygon is maximized. The support polygon 400 when changed to a morphology is illustrated. At this time, when the robot device 100 has the forward direction as the traveling direction, the margin in the traveling direction of the geometric center of gravity of the support polygon 400 is as shown in Reference No. 401, and the margin of the geometric center of gravity before changing the walking form. It can be seen that it is more extended than 301 (see FIG. 3). Although inertia acts in the traveling direction of the robot device 100, the ZMP or the mass center of gravity can be easily accommodated in the supporting polygon 400 by expanding the margin 401 in the traveling direction of the geometric center of gravity of the supporting polygon 400. The operation of the robot device 100 that retracts to a safe place is stabilized.

A mechanism for changing the walking mode by the remaining available legs when a failure of the right front leg 120 (RR) of the robot device 100 occurs near a curve at a right angle of the passage will be described with reference to FIGS. 5 and 6. To do.

FIG. 5 shows a state in which the right front leg 120 (RF) of the robot device 100 has failed before the right-angled curve of the passage. At this time, the remaining three legs, the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR), form the support polygon 500 of the robot device 500. At this point, the shape of the support polygon 500 is independent of the shelter 501.

In FIG. 6, when the robot device 100 moves to the evacuation site 601 set outside the curve, walking by the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR). It shows how the form of movement was changed. The support polygon 600 for retracting to a safe place is configured as an isosceles triangle having the tip of the left front leg 110 (LF) as an apex and the apex facing the evacuation location 601. The traveling direction of the robot device 100 is the direction toward the evacuation site 601, and the margin in the traveling direction of the geometric center of gravity of the support polygon 600 is expanded. Therefore, it becomes easy to accommodate the ZMP or the center of gravity of the mass in the support polygon 600, and the operation of the robot device 100 that retracts to a safe place is stabilized.

When the robot device 100 moves using three legs, the operation of using one of the legs as a free leg and the remaining two legs as a stance is repeatedly executed. In the section where the robot device 100 main body is supported by the two legs, the supporting polygon is only the area connecting the two legs that serve as the stance, and the posture becomes unstable. Therefore, the next landing point of the leg that is currently used as a free leg is planned in consideration of future stabilization. By doing so, it is possible to realize movement so as not to fall while maintaining the posture of the robot device 100.

Further, when the robot device 100 moves using three legs, in order to reduce the risk of further damage as much as possible, the remaining available legs are switched to swing legs one by one so that the robot device 100 moves by walking. However, if it is difficult to switch between standing and swinging legs due to imbalance, or if you want to evacuate urgently, or because of other reasons such as the number of broken legs or the weight balance of the robot device 100, evacuation by walking. If the operation cannot be performed, it may be realized by jumping or the like.

FIG. 7 shows an example of the gait before and after the failure of the right front leg 120 (RF) of the robot device 100. In the figure, LF indicates the left front leg 110, RF indicates the right front leg 120, LR indicates the left rear leg 130, and RR indicates the right rear leg 140, and the transition of the state for each leg (swing or standing leg) with the lateral direction as the time direction. Which of the above, and whether it is out of order) is shown. The robot device 100 assumes that the gait is performed in a predetermined walking cycle, and the figure illustrates the gait for three cycles.

In FIG. 7, in the first cycle, all four legs are operating normally, and normal walking motion is performed. In the second cycle, the right front leg 120 (RF) failed and became inoperable. In the second and subsequent cycles, the remaining available right front leg (RF), leg 130 with left hind leg (LR), and leg 140 with right hind leg (RR) at the same time are swinging sections. Have. In the third cycle, the available right front leg (RF), leg 130 is switched to the left hind leg (LR), and leg 140 is switched to the right hind leg (RR) one by one, and the walking is changed in form. The operation is being carried out.

B-2. Operation example 2 when a leg breaks down
When changing to a walking mode with the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR), the failed right front leg 120 (RF) may be moved to a position where it does not get in the way. preferable.

8 and 9 show an example of the gait of the robot device 100 when the failed right front leg 120 (RF) is moved to a position where it does not get in the way. However, FIG. 8 shows a state in which the robot device 100 is viewed from the front, and FIG. 9 shows a state in which the robot device is viewed from the right side. As shown in the figure, the

joints

123 and 124 of the right front leg 120 (RF) are driven around the pitch axis, respectively, and the links are folded and retracted toward the body 101 so as not to get in the way. There is. Further, by driving the joint portion 114 of the left front leg 110 around the roll axis and moving the toes closer to the center of the body portion 101, the supporting polygon has the toes of the left front leg 110 (LF) as the apex. A support polygon that becomes an isosceles triangle is constructed so that the margin in the traveling direction of the geometric center of gravity of the support polygon is maximized.

It should be noted that, as another method of preventing the broken leg from interfering with the walking motion of other available legs, it is possible to remove the broken leg from the body 101. As shown in FIGS. 8 and 9, when the broken leg cannot be retracted to an unobtrusive position, a method of removing the broken leg is effective. There is also an advantage that the weight of the device is reduced by removing the broken leg, which makes it easier to walk. However, it is premised that the legs 110 to 140 have a structure that can be attached and detached from the body portion 101, and that the legs 110 to 140 can be removed by a command from the main control unit 231 and the like. However, it is necessary to pay sufficient attention to the location of removal so that the legs after removal do not become obstacles to other moving objects that share the work space. The legs 110 to 140 may have a structure in which the entire leg can be attached / detached from the body portion 101 at the first joint, or the second link intention may be attached / detached at the second joint. It may be possible to specify the part to be used.

B-3. Operation example 3 when a leg breaks down
In the operation example 2 introduced in B-2 above, the robot device 100 is retracted to a safe place without using the broken leg at all. However, even if a leg breaks down, it may not be completely usable, or it may be partially usable and have residual capacity.

For example, even if the second link 121 of the right front leg 120 (RF) or the distal end side thereof is impaired, but the second link 121 cannot be used, the first joint 124 operates normally and the first joint 124 is the second. One link 122 can be used and may have residual capacity. In such a case, the robot device 100 operates normally according to the remaining capacity of the failed right front leg 120 (RF), the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 ( By changing the walking mode of RR), the evacuation motion to a safe place may be performed by the walking motion in which the walking motion is changed while using all four legs.

FIG. 10 illustrates a state in which the robot device 100 changes the form of another normal leg according to the remaining ability of the failed leg and walks. In the illustrated example, it is assumed that the first joint 124 of the right front leg 120 (RF) operates normally and the first link 122 can be used and has a residual capacity. In such a case, in all the legs 110 to 140, the second link is bent and folded by the second joint, so that the

second joints

113, 123, 133, and 143 are used as grounding points instead of the toes. Evacuate to a safe place by walking on four legs. By using four legs, the supporting polygon becomes larger than in the case of three legs, so that a stable evacuation operation can be realized.

B-4. Operation example 4 when a leg breaks down
Here, the operation at the time of failure of the robot device 100 in which the wheels are mounted on the toes of the legs 110 to 140 will be considered. When any one leg breaks down and only three legs can be used, it is desirable to change the walking form so that the supporting polygon becomes an isosceles triangle.

FIG. 11 is composed of the remaining left front leg 110 (LF), left rear leg 130 (LR), and right rear leg 140 (RR) when the right front leg 120 (RF) of the robot device 100 fails. The support polygon 1100 is illustrated. In this case, the support polygon 1100 has a side LF-RR as a hypotenuse and is a right triangle that is asymmetric (that is, left-right asymmetric) with respect to the traveling direction, but the rotational torque of the right hind leg 140 (RR) is large when turning. turn into.

Therefore, as shown in FIG. 12, the walking modes of the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR) are changed so as to form a support polygon 1200 having an isosceles triangle. Change. As a result, the rotational torque of the right rear leg 140 (RR) can be reduced when turning.

Also, let's compare the performance when going straight between the case where the walking form is not changed and the case where the walking form is changed so that the supporting polygon becomes an isosceles triangle.

As shown in FIG. 13, if the walking mode is not changed, the line connecting the geometric center of gravity of the supporting polygon 1300 and the traveling direction when going straight becomes asymmetrical, which complicates wheel control. If the torque distribution of the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR) is not determined in consideration of the mass balance of the robot device 100, the robot device 100 should move in any direction. Can't.

On the other hand, as shown in FIG. 14, the walking modes of the left front leg 110 (LF), the left rear leg 130 (LR), and the right rear leg 140 (RR) are arranged so as to form a support polygon 1400 having an isosceles triangle. When changing, the line connecting the geometric center of gravity of the supporting polygon 1400 and the traveling direction when traveling straight is symmetrical, so that the wheel can be easily controlled. When the support polygon 1400 is an isosceles triangle, it can be moved in any direction by adjusting the torque balance of the left hind leg 130 (LR) and the right hind leg 140 (RR) as follows. Can be done.

As described above, when the toes of the legs 110 to 140 of the robot device 100 are wheels, as shown in FIGS. 12 and 14, the leg forms that can be used so as to form an appropriate supporting polygon. By changing, the control method during wheel operation with the available legs can be simplified and the load on the wheel drive motor can be reduced.

B-5. Notification / Alarm at the time of leg failure Another feature of the operation method proposed in this specification for minimizing the risk of secondary damage is that when the leg of the robot device 100 breaks down or the robot device 100 is safe. During the period of evacuation to a suitable place, notify the external device and give an alarm to the surroundings.

The external device referred to here is, for example, an information terminal (smartphone, tablet, etc.) operated by the administrator of the robot device 100. The notification to the external device shall be made by using wired communication or wireless communication via the communication unit 235. For example, wireless technology such as Wi-Fi (registered trademark), Bluetooth (registered trademark), and LTE (Long Term Evolution) can be used to notify an external device from the robot device 100. Since the robot device 100 itself cannot repair the broken leg or collect the robot device 100 itself, it notifies the administrator and requests repair or collection from the site.

For example, the robot device 100 notifies the external device of the result of the leg failure diagnosis and the information of the position selected as the evacuation location. On the other hand, the administrator may receive the notification from the robot device 100 and give the robot device 100 the designation of the evacuation location and the instruction of the evacuation operation via the external device.

In addition, an alarm is given to notify the surroundings that the robot device 100 with a broken leg is stopped on the aisle and that the robot device 100 is moving to a safe place. The alarm is executed by using the output of a voice message from the speaker 221, the generation of a beep sound, the character display by the display unit 222, the lighting of the revolving light, or other output device included in the robot device 100. Even after the robot device 100 has been evacuated to a safe place, it is noisy if the voice message and beep sound continue to be heard. Only notification may be given.

B-6. Operation Flow at the Time of Leg Failure FIG. 15 shows an operation procedure executed by the robot device 100 when a part of the legs fails in the form of a flowchart. The illustrated operation procedure shall be carried out under the overall control of the main control unit 231.

The robot device 100 constantly monitors whether or not any of the legs 110 to 140 has a failure during movement (step S1501).

Here, the method of detecting the failure of the legs 110 to 140 is not particularly limited. For example, a leg failure can be detected when the torque generated in the joint drive motor shows an abnormal value, or when the rotation angle of the joint measured by using an encoder or the like greatly deviates from the indicated value. ..

When a failure is detected in any of the legs 110 to 140 (Yes in step S1501), the robot device 100 first notifies the external device (step S1502).

The external device referred to here is, for example, an information terminal (smartphone, tablet, etc.) operated by the administrator of the robot device 100. Alternatively, the external device may be an alarm or a warning light. The notification to the external device shall be made by using wired communication or wireless communication via the communication unit 235. The administrator who receives the notification may repair the legs, collect the robot device 100 main body, and the like. The robot device 100 may continue to notify the external device until this process is completed, and sequentially report the progress of subsequent work such as evacuation to a safe place.

Next, the robot device 100 implements the treatment of the leg that has detected the failure (step S1503).

Here, the treatment of the failed leg includes an operation of retracting the failed leg to a position that does not interfere with the operation of retracting to a safe place using the remaining normal legs. For example, the robot device 100 may fold and retract the failed leg (see FIGS. 8 and 9). Further, as a treatment for the broken leg, the broken leg may be removed from the robot device 100 main body (or the body portion 101).

Next, the robot device 100 searches for a safe evacuation site (step S1504).

The robot device 100 may autonomously search for a safe place based on the surrounding images taken by the

cameras

211L and 211R. A safe place is, for example, the end of a passage. If the leg of the robot device 100 breaks down near a curve at right angles to the passage, the outside of that curve becomes a safe place (see, for example, FIG. 6). The robot device 100 may search for a safe place by using a self-position estimation technique such as a SLAM (Simultaneusly Localization and Mapping) method. Further, the robot device 100 may search for a safe place based on a wireless command from an external device (such as an information terminal operated by an administrator).

Then, the robot device 100 checks whether or not it can be evacuated to a safe place (step S1505).

When it is possible to evacuate to a safe place (Yes in step S1505), the robot device 100 issues an alarm from the speaker 221 to notify the surroundings that the robot device 100 is moving to the evacuation place (step S1506). , The remaining capacity of the leg is used to move to the evacuation site (step S1507).

In step S1506, the robot device 100 uses the output of a voice message from the speaker 221, the generation of a beep sound, the character display by the display unit 222, the lighting of the revolving light, or other output device included in the robot device 100. Implement an alarm.

Further, in step S1507, the robot device 100 switches the remaining available legs to swing legs one by one (see, for example, FIG. 7), and moves to a safe evacuation site by walking. The robot device 100 may remove the failed leg from the body portion 101 when the walking motion is performed only with the available legs. By removing the broken leg, it does not interfere with the walking movements of the available legs. In addition, removing the broken leg reduces the weight of the device and has the advantage of making it easier to walk. However, it is necessary to pay sufficient attention to the location of removal so that the legs after removal do not become obstacles to other moving objects that share the work space.

The robot device 100 stabilizes the posture by enlarging the supporting polygon with the remaining available legs when moving to a safe evacuation site. Further, the robot device 100 changes the walking posture by the remaining available legs so that the margin in the traveling direction of the geometric center of gravity of the supporting polygon is maximized (see, for example, FIG. 4). Stabilize your posture and prevent falls.

Alternatively, in step S1507, the robot device 100 changes all the legs 110 to 140 (or a plurality of legs including the failed leg) by changing the walking mode of the normal leg according to the remaining ability of the failed leg. ) May be used to move to a safe evacuation site by a walking motion (see, for example, FIG. 10).

Alternatively, in step S1507, the robot device 100 may be realized by jumping or the like when it is urgently criticized or when the evacuation operation by walking cannot be performed (see, for example, FIG. 7). ..

In step S1507, regardless of which method is used to evacuate to a safe place, the robot device 100 checks the surrounding environment and starts moving when it is determined that the risk of secondary damage is low. Is desirable.

After that, when the robot device 100 reaches a safe evacuation place, it stops there (step S1508) and waits for the supervisor or the like to repair the broken leg or collect the robot device 100 itself.

Further, the robot device 100 issues an alarm indicating that the robot device 100 is stopped at a safe evacuation site (step S1509).

In step S1509, the robot device 100 uses the output of a voice message from the speaker 221, the generation of a beep sound, the character display by the display unit 222, the lighting of the revolving light, or other output device included in the robot device 100. Implement an alarm. However, since the safety is guaranteed to some extent at the evacuation site and the risk of secondary damage is low, even a lighter alarm (for example, only turning on the revolving light) than the alarm given while moving to the evacuation site in step S1506 is used. Good.

On the other hand, if the robot device 100 cannot stand by in a safe place (No in step S1505), the robot device 100 stops at the place where a leg failure is detected (step S1510) and stops on the aisle. An alarm is issued to notify the surroundings that the robot is doing (step S1511).

In step S1511, the robot device 100 uses the output of a voice message from the speaker 221, the generation of a beep sound, the character display by the display unit 222, the lighting of the revolving light, or other output device included in the robot device 100. Implement an alarm. However, stopping in the aisle has a much higher risk of secondary damage than moving to the evacuation site, so a stronger alarm (for example, a voice message or a beep) than the alarm given while moving to the evacuation site in step S1506. Increase the volume of the light, increase the light intensity of the revolving light, etc.).

C. Effect The robot device 100 can reduce the risk of secondary damage when a part of the legs breaks down by pre-programming the processing procedure as shown in FIG.

Further, when carrying out the processing procedure as shown in FIG. 15, the robot device 100 is equipped with two or more motors for one joint, or is equipped with a large number of legs in case of a leg failure. There is no need, and the risk of secondary damage can be reduced at low cost.

Further, since the robot device 100 has a function of notifying an external device (such as an information terminal operated by an administrator) or notifying the surroundings when a leg failure occurs, it causes secondary damage. The risk can be reduced.

In addition, since the robot device 100 autonomously performs an operation of ensuring safety when a leg failure occurs, the resistance to use in an environment without human intervention is enhanced.

Further, when the toes of each leg 110 to 140 of the robot device 100 are wheels, the wheels on the available legs can be changed by changing the form of the available legs so as to have an appropriate supporting polygon. The control method during operation is simplified, and the load applied to the wheel drive motor can be reduced.

The techniques disclosed in the present specification have been described in detail with reference to the specific embodiments. However, it is self-evident that one of ordinary skill in the art can modify or substitute the embodiment without departing from the gist of the technique disclosed herein.

In this specification, the embodiment in which the technique disclosed in the present specification is applied to a robot device composed of four legs has been mainly described, but the robot device equipped with two legs, three legs, or five or more legs has been described. Against this, the techniques disclosed herein can be applied as well.

Further, the technique disclosed in this specification can be similarly applied to a robot device or a mobile device provided with a plurality of moving means other than the legs. For example, in a wheel-type mobile device (including an autonomous vehicle) equipped with multiple wheels, if some wheels fail (including when the rotary motor fails or punctures), multiple rotor blades By applying the techniques disclosed herein in the event that some rotorcraft fail (including when the rotorcraft fails or the rotorcraft breaks) in an unmanned aerial vehicle (drone) equipped with , It is possible to evacuate to a safe place and suppress secondary damage such as collision with other moving objects.

In short, the technology disclosed in this specification has been described in the form of an example, and the contents of this specification should not be interpreted in a limited manner. The scope of claims should be taken into consideration in determining the gist of the technology disclosed herein.

The technology disclosed in this specification can also have the following configuration.

(1) With multiple legs
A detection unit that detects whether or not each of the plurality of legs is out of order,
A control unit that controls the operation according to the detection unit detecting a failure in any of the plurality of legs.
A robot device equipped with.

(2) Further equipped with a communication unit that communicates with an external device
The control unit notifies the external device of information about the leg that has detected the failure via the communication unit.
The robot device according to (1) above.

(3) The control unit controls an operation for retracting the robot device to a safe place by utilizing the remaining capacity of the legs.
The robot device according to any one of (1) and (2) above.

(4) The control unit controls to evacuate to the safe place by walking using the leg that has not failed.
The robot device according to (3) above.

(5) The control unit controls so that the support polygon composed of the non-failed legs is maximized when evacuating to the safe place.
The robot device according to (4) above.

(6) The control unit controls so that the margin of the geometric center of gravity of the supporting polygon with respect to the traveling direction to the safe place is maximized.
The robot device according to any one of (4) and (5) above.

(7) The control unit controls the removal of the failed leg.
The robot device according to any one of (4) to (6) above.

(8) The control unit changes the walking mode of the normal leg according to the remaining ability of the failed leg, and walks using a plurality of legs including the failed leg to the safe place. Control to evacuate,
The robot device according to any one of (3) to (7) above.

(9) The control unit controls an operation of notifying the surroundings that the evacuation is being carried out to the safe place.
The robot device according to any one of (3) to (8) above.

(10) Further equipped with a communication unit that communicates with an external device,
The control unit controls an operation for evacuating to the safe place notified from the external device.
The robot device according to any one of (3) to (9) above.

(11) A control method for a robot device having a plurality of legs.
A step of detecting whether or not each of the plurality of legs is defective,
A step of performing an action according to the detection of a failure in any of the plurality of legs, and
A method of controlling a robot device having.

(12) The robot device includes a communication unit that communicates with an external device.
The method for controlling a robot device according to (11) above, further comprising a step of notifying the external device of information about a leg that has detected a failure via the communication unit.

(13) The method for controlling a robot device according to any one of (11) and (12) above, further comprising an evacuation step of retracting the robot device to a safe place by utilizing the remaining capacity of the legs.

(14) The method for controlling a robot device according to (13) above, wherein in the evacuation step, the robot device is evacuated to the safe place by walking using the leg that has not failed.

(15) The control of the robot device according to (14) above, in which in the evacuation step, the support polygon composed of the non-failed legs is maximized when the robot device is evacuated to the safe place. Method.

(16) The robot apparatus according to any one of (14) and (15) above, wherein in the evacuation step, the margin of the geometric center of gravity of the supporting polygon with respect to the traveling direction to the safe place is maximized. Control method.

(17) The method for controlling a robot device according to any one of (14) to (16) above, further comprising a step of removing the failed leg from the robot device main body.

(18) In the evacuation step, the walking mode of the normal leg is changed according to the remaining capacity of the failed leg, and walking using a plurality of legs including the failed leg to the safe place. The method for controlling a robot device according to any one of (13) to (17) above, wherein the robot device is retracted.

(19) The method for controlling a robot device according to any one of (13) to (18) above, further comprising a step of notifying the surroundings that the robot is being evacuated to the safe place.

(20) The robot device includes a communication unit that communicates with an external device.
The method for controlling a robot device according to any one of (13) to (19) above, wherein in the evacuation step, the robot device is evacuated to the safe place notified from the external device.

100 ... Robot device, 101 ... Loading part 110 ... Movable legs 111 ... Link (second link), 112 ... Link (first link)
113 ... Joint (second joint), 114 ... Joint (first joint)
120 ... Movable legs 121 ... Link (second link), 122 ... Link (first link)
123 ... Joint (second joint), 124 ... Joint (first joint)
130 ... Movable legs 131 ... Link (second link), 132 ... Link (first link)
133 ... Joint (second joint), 134 ... Joint (first joint)
140 ... Movable legs 141 ... Link (second link), 142 ... Link (first link)
143 ... Joint (second joint) 144 ... Joint (first joint)
210 ... External sensor unit, 211L, 211R ... Camera 212 ... Microphone, 213 ... Touch sensor 221 ... Speaker, 222 ... Display unit 230 ... Control unit, 231 ... Main control unit, 232 ... Battery 233 ... Internal sensor unit 233A ... Battery sensor , 233B ... Accelerometer 234 ... External memory, 235 ... Communication unit

Claims

With multiple legs,
A detection unit that detects whether or not each of the plurality of legs is out of order,
A control unit that controls the operation according to the detection unit detecting a failure in any of the plurality of legs.
A robot device equipped with.
It also has a communication unit that communicates with external devices.
The control unit notifies the external device of information about the leg that has detected the failure via the communication unit.
The robot device according to claim 1.
The control unit controls an operation for retracting the robot device to a safe place by utilizing the remaining capacity of the legs.
The robot device according to claim 1.
The control unit controls to evacuate to the safe place by walking using the leg that has not failed.
The robot device according to claim 3.
The control unit controls so that the support polygon composed of the non-failed legs is maximized when the evacuation to the safe place is performed.
The robot device according to claim 4.
The control unit controls so that the margin of the geometric center of gravity of the supporting polygon with respect to the traveling direction to the safe place is maximized.
The robot device according to claim 4.
The control unit controls the removal of the failed leg.
The robot device according to claim 4.
The control unit changes the walking mode of the normal leg according to the remaining ability of the failed leg, and evacuates to the safe place by walking using a plurality of legs including the failed leg. To control,
The robot device according to claim 3.
The control unit controls an operation of notifying the surroundings that the user is evacuating to the safe place.
The robot device according to claim 3.
It also has a communication unit that communicates with external devices.
The control unit controls an operation for retracting to the safe place notified from the external device.
The robot device according to claim 3.
It is a control method for a robot device equipped with multiple legs.
A step of detecting whether or not each of the plurality of legs is defective,
A step of performing an action according to the detection of a failure in any of the plurality of legs, and
A method of controlling a robot device having.