JP2012091300A - Legged robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the stability of the posture of a robot body by the control using a pressure sensor during four leg walking, by avoiding the gripping surface of a hand finger from being damaged during four leg walking.SOLUTION: The four leg walking is stably performed by a knuckle walking using hands 209, 212 installed in upper limbs of a legged robot having four limbs. In the right hand 209, hand pressure sensors 107a, 112a for ground detection are arranged at finger dorsal surfaces 125a, 126a of two fingers 101a, 102a. Moreover, in the left hand 212, hand pressure sensors 107b, 112b for ground detection are arranged at finger dorsal surfaces 125b, 126b of two fingers 101b, 102b. The posture at the knuckle walking is controlled by using these hand pressure sensors 107a, 112a, 107b and 112b.

Description

  The present invention relates to a legged robot that has four limbs and performs bipedal walking and quadrupedal walking.

  In recent years, various legged mobile robots that perform bipedal walking and quadrupedal walking have been developed. Among them, research on robots that can take many forms of movement, such as bipedal walking, quadrupedal walking, ladder climbing, and branching (see Non-Patent Document 1). Since a single robot can take many forms of movement, it can move in various environments.

  One form of a robot that supports human life is to always be on the side of the person and carry out light tasks such as bringing objects and tidying up. Since the moving means is difficult to move a step such as a staircase with a wheel type, a leg type is desirable. In addition, since light work is limited in the gripper, it is desirable to provide a multi-finger hand in the hand. By providing a multi-fingered hand, the door knob can be grasped and the door can be opened and closed.

  A biped walking robot has been developed as a legged robot and is already on the market as a hobby robot. In order to perform biped walking stably, it is necessary to model the robot and the environment (floor surface, etc.) and generate motion based on it. Even for static walking that does not require consideration of dynamics, the control of placing the projected point of the center of gravity on the soles of the supporting legs is not easy to cope with objects placed on the floor, floor surfaces with different surface conditions, stairs, etc. Absent. On the other hand, in quadruped walking, the center of gravity projection should be placed within a tripod support polygon, so control is much easier compared to biped walking.

Yoneda Hironari, Sekiyama Kosuke, Hasegawa Yasuhisa, Fukuda Toshio, “Vertical Ladder Climbing Motion Considering Angular Momentum Consideration of Multilocomotion Robots”, 26th Annual Conference of the Robotics Society of Japan, RSJ2008AC1D2-01, 2008

  By the way, the gripping surface of a finger corresponding to the palm side of a human or an ape is sensitive. The same applies to the fingertips of a multi-fingered hand having a high robot gripping function. When a legged robot makes a four-legged walk and touches the hand of the upper limb, it is necessary to protect the gripping surface of the finger on the hand.

  In addition, quadruped walking is easier as compared to biped walking, but it is easier to control, but it is necessary to grasp the center of gravity. For this reason, legged robots that perform four-legged walking require posture sensors such as gyros and acceleration sensors, force sensors for the four limbs, and pressure sensors that touch the walking surface such as the ground on the feet and hands. There is. However, there has been no example of a legged robot that has a multi-fingered hand and performs four-legged walking, and contact detection by a pressure sensor at the time of touching the finger has not been performed.

  Therefore, the present invention avoids the gripping surface of the finger part of the hand from being damaged when walking on four legs, and improves the stability of the posture of the robot body by control using a pressure sensor when walking on four legs. The purpose is to provide a robot.

  The present invention includes a robot body having a trunk, two lower limbs connected to the trunk, and two upper limbs connected to the trunk, and each of the lower limbs is in walking. Each of the upper limbs has an arm part and a hand part connected to the arm part and capable of gripping a gripping object, and using the two lower limb parts. In a legged robot capable of walking on two legs and capable of walking on four legs using the two lower limbs and the two upper limbs, a hand for detecting whether or not each of the hands touches the walking surface. A body pressure sensor, a foot pressure sensor for detecting whether or not each of the feet touches the walking surface, and a center of gravity of the robot body based on detection results of the hand pressure sensor and the foot pressure sensor. A control unit that controls the posture of the robot body, and each hand unit is a quadruped walking The finger joint is bent to contact the back surface of the finger opposite to the gripping surface to the walking surface, and the hand pressure sensor is installed on the finger back surface of the finger portion of each hand portion. It is characterized by that.

  The present invention also includes a robot body having a trunk, two lower limbs connected to the trunk, and two upper limbs connected to the trunk, and each lower limb is a walking Each of the upper limbs has an arm part and a hand part connected to the arm part and capable of gripping the object to be gripped. In a legged robot that can be walked on two legs and can walk on four legs using the two lower limbs and the two upper limbs, it is detected whether or not each hand part touches the walking surface. A hand pressure sensor, a foot pressure sensor that detects whether or not each foot is in contact with the walking surface, and a center of gravity of the robot body based on a detection result of the hand pressure sensor and the foot pressure sensor. And a control unit for controlling the posture of the robot main body, and each of the hand units is 4 Bending the finger joints during walking and having a plurality of finger portions that contact the back surface of the finger opposite to the gripping surface with the walking surface, the hand pressure sensor is installed on the finger back surface of each finger portion of each hand portion It is characterized by being.

  According to the present invention, the four-legged walking is performed by grounding the finger back surface of the finger portion of each hand portion to the walking surface. Thereby, it is possible to avoid the gripping surface of the finger part of the hand part from being damaged when walking on four legs. When walking on four legs, the posture stability of the robot body can be improved by the posture control of the robot body using each pressure sensor.

1 is a perspective view showing a schematic configuration of a legged robot according to a first embodiment of the present invention. It is a perspective view which shows the structure of each hand part, (a) is a perspective view of a left hand part, (b) is a perspective view of a right hand part. It is a figure which shows the movement operation | movement of a legged robot, (a) is a knuckle walk, (b) is a bipedal walk, (c) is a 3 legged walk, (d) is a figure which shows a climbing action. It is a block diagram which shows schematic structure of the control system of a legged robot. It is a block diagram which shows the connection state in the upper limb unit of a control system. It is the schematic diagram which looked at the legged robot from the top, in order to explain the walking stability in static walking. (A) is a four-leg support state in a knuckle walk. (B) is a three-leg support state in a knuckle walk or a three-leg walk for carrying an object. (C) is a two-legged support state in a three-legged walking or a two-legged support state in a two-legged walking. (D) is a one-leg support state with two legs walking. It is a flowchart explaining the walking control in four-legged walking (knuckle walking). It is a flowchart explaining the walking control in a three-legged walking. It is a figure which shows the earthing | grounding state when performing grounding control of the hand part of the legged robot which concerns on 1st Embodiment, (a) is the state before grounding control of a hand part, (b) is grounding control of a hand part. The later state is shown. It is a flowchart of the earthing | grounding control by the control system of the legged robot which concerns on 1st Embodiment. It is a figure which shows the grounding state when performing the grounding control of the hand part of the legged robot which concerns on 2nd Embodiment, (a) is the state before the grounding control of a hand part, (b) is the grounding control of a hand part. The later state is shown. It is a flowchart of the grounding control by the control system of the legged robot which concerns on 2nd Embodiment.

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

[First Embodiment]
FIG. 1 is a perspective view showing a schematic configuration of a legged robot according to the first embodiment of the present invention. As shown in FIG. 1, the robot body 100A of the legged robot 100 includes a trunk 205, a head 206 coupled to the trunk 205, two upper limbs 201 and 202 coupled to the trunk 205, Two lower limbs 203 and 204 connected to the trunk 205. The legged robot 100 is configured to be able to walk on two legs using two lower limbs 203 and 204, and to be able to walk on four legs using two lower limbs 203 and 204 and two upper limbs 201 and 202. ing.

  An upper right limb 201 and a right lower limb 203 are provided on the right side of the trunk 205, and a left upper limb 202 and a left lower limb 204 are provided on the left of the trunk 205. That is, the upper right limb 201 and the left upper limb 202 are arranged symmetrically with respect to the XZ plane. Further, the right lower limb portion 203 and the left lower limb portion 204 are arranged symmetrically with respect to the XZ plane. The trunk 205 includes a chest 219, an abdomen 220, and a waist 221, and a head 206 is connected to the upper part of the chest 219.

  Each of the upper limbs 201 and 202 includes arm parts 231 and 232 and hand parts 209 and 212. Specifically, the upper right limb 201 includes an upper right arm 207 having a proximal end connected to the right side of the chest 219 of the trunk 205 and a right forearm 208 having a proximal end connected to the distal end of the upper right arm 207. And a right arm portion 231. The right upper limb portion 201 has a right hand portion 209 that is connected to the right forearm 208 of the right arm portion 231 so as to be rotatable about the axis of the right arm portion 231. Further, the right hand portion 209 is connected to the right arm portion 231 so as to be swingable.

  The left upper limb 202 is a left arm that includes a left upper arm 210 having a base end connected to the left side of the chest 219 of the trunk 205 and a left forearm 211 having a base end connected to the tip of the left upper arm 210. 232. The left upper limb 202 has a left hand 212 connected to the left forearm 211 of the left arm 232 so as to be rotatable about the axis of the left arm 232. Further, the left hand portion 212 is swingably connected to the left arm portion 232. Each of the hand portions 209 and 212 is a multi-fingered hand having a plurality of (three in the first embodiment) fingers so as to be able to grip a gripping object.

  The lower limbs 203 and 204 have feet 215 and 218 that are in contact with a walking surface such as a ground surface or a floor surface during walking. More specifically, the right lower limb 203 has a right thigh 213 whose base end is connected to the lower part of the waist 221 of the trunk 205 and a base end connected to the tip of the right thigh 213. The right leg part 214 and the right leg part 215 connected to the tip part of the right leg part 214 are provided. The left lower limb 204 includes a left thigh 216 having a base end connected to the lower portion of the waist 221 of the trunk 205 and a left lower leg having a base connected to the distal end of the left thigh 216. 217 and a left foot 218 connected to the tip of the left crus 217.

  Although not shown, each unit has the following degrees of freedom, and includes actuators and sensors necessary for driving and controlling the units. The head 206 has a degree of freedom of 3 (breakdown: yaw axis, pitch axis, roll axis), and the trunk 205 has a degree of freedom of 3 (breakdown: yaw axis, pitch axis, roll axis). Each of the upper limbs 201 and 202 has a degree of freedom of 7 (breakdown: shoulder pitch axis, shoulder roll axis, upper arm yaw axis, elbow pitch axis, forearm yaw axis, wrist pitch axis, wrist roll axis). The lower limbs 203 and 204 have 6 degrees of freedom (breakdown: crotch yaw axis, crotch pitch axis, crotch roll axis, knee pitch axis, ankle pitch axis, ankle roll axis). Each of the hand portions 209 and 212 has 6 degrees of freedom, and each of the foot portions 215 and 218 has 6 degrees of freedom. These degrees of freedom are examples. The legs 215 and 218 are redundant in order to make them more suitable for climbing, but it is also possible to have two degrees of freedom of the roll axis and the pitch axis. In addition, either one of the yaw axes of the upper arm portions 207 and 210 and the forearm portions 208 and 211 can be omitted.

  Next, the structure of each hand part 209,212 is demonstrated in detail. 2 is a perspective view showing the configuration of each of the hand portions 209 and 212. FIG. 2 (a) is a perspective view of the left hand portion 212, and FIG. 2 (b) is a perspective view of the right hand portion 209.

  As shown in FIG. 2A, the left hand portion 212 is connected to the left forearm 211 via the wrist 105b. The left hand unit 212 has three fingers, the index finger 101b, the middle finger 102b, and the thumb finger 103b. The fingers 101b and 102b bend at the finger joints toward the palm 104b when holding the object to be held.

  Each finger 101b, 102b, 103b has two joints, and each finger joint has one degree of freedom. The index finger 101b is connected to the first link 108b disposed at the tip, the first finger joint 109b to the first link 108b, and the second finger joint 111b to the second link 110b connected to the hand body 106b. have. The middle finger 102b is connected to the first link 113b disposed at the tip, the first finger joint 114b to the first link 113b, and the second finger joint 116b to the second link 115b connected to the hand body 106b. have. The thumb finger 103b is connected to the first link 117b disposed at the tip, the first finger joint 118b to the first link 117b, and the second finger joint 120b to the second link 119b connected to the hand body 106b. have.

  In the coordinate system shown in FIG. 2A, the first finger joint 109b, the second finger joint 111b of the index finger 101b, the first finger joint 114b of the middle finger 102b, and the second finger joint 116b have a degree of freedom of the roll axis. Yes. The first finger joint 118b of the thumb 103b has a degree of freedom of the pitch axis. The second finger joint 120b has a degree of freedom of the yaw axis. 2A shows the left hand portion 212, and the right hand portion 209 is symmetrical with the left hand portion 212 in the XZ plane and is shown in FIG. 2B.

  As shown in FIG. 2B, the right hand part 209 is connected to the right forearm 208 via the wrist 105a. The right hand unit 209 has three fingers, an index finger 101a, a middle finger 102a, and a thumb finger 103a. Each finger 101a, 102a bends to the palm 104a side at each finger joint when grasping the grasped object.

  Each finger 101a, 102a, 103a has two joints, and each finger joint has one degree of freedom. The index finger 101a is connected to the first link 108a arranged at the tip, the first finger joint 109a to the first link 108a, and the second finger joint 111a to the second link 110a connected to the hand body 106a. have. The middle finger 102a is connected to the first link 113a disposed at the tip, the second finger 115a connected to the first link 113a by the first finger joint 114a, and the second link 115a connected to the hand body 106a by the second finger joint 116a. have. The thumb 103a is connected to the first link 117a disposed at the tip, the first finger joint 118a to the first link 117a, and the second finger joint 120a to the second link 119a connected to the hand body 106a. have.

  When gripping the gripping object with the right hand unit 209, the gripping surface 121a of the first link 108a and the gripping surface 122a of the second link 110a of the index finger 101a are brought into contact with the gripping object. Further, the gripping surface 123a of the first link 113a and the gripping surface 124a of the second link 115a of the middle finger 102a are brought into contact with the gripping object.

  When gripping the gripping object with the left hand portion 212, the gripping surface 121b of the first link 108b and the gripping surface 122b of the second link 110b of the index finger 101b are pressed against the gripping object. Further, the gripping surface 123b of the first link 113b of the middle finger 102b and the gripping surface 124b of the second link 115b are pressed against the gripping object.

  By the way, in an ape having fingers that can be gripped, the back of the finger of the hand is put on the ground when walking on four legs. This is called knuckle walking. In the first embodiment, the legged robot 100 uses two-legged walking and four-legged walking depending on the situation, and during the four-legged walking, the standing posture is less likely to have a difference in posture, and to the fingers of the hand. Because it can reduce the load of the knuckle walking. The knuckle walking is suitable for a standing posture because a part of the hand can be included in the substantial length of the upper limb when walking on four legs. Further, when considering a size that does not get in the way, the ratio of the length of the hand portions 209 and 212 to the height of the robot main body 100A increases. This is because the number of finger joints of the hand portions 209 and 212 which are multi-finger hands is large and the mechanism becomes complicated. By using knuckle walking, the lengths of the hand portions 209 and 212 can be utilized in the above-mentioned standing posture.

  Specifically, in the first embodiment, when walking on four legs, as shown in FIG. 2, the index fingers 101a and 101b of the respective hands 209 and 212 are bent at the first finger joints 109a and 109b, and the middle finger 102a and 102b are bent at the first finger joints 114a and 114b. Then, the finger back surface 125a of the index finger 101a of the right hand part 209 opposite to the grip surface 121a of the first link 108a is grounded to the walking surface, and the finger of the middle finger 102a opposite to the grip surface 123a of the first link 113a is grounded. The back surface 126a is grounded to the walking surface. Similarly, the finger back surface 125b opposite to the grip surface 121b of the first link 108b of the index finger 101b of the left hand portion 212 is grounded to a walking surface such as the ground or a floor surface, and the grip surface of the first link 113b of the middle finger 102b. The finger back 126b opposite to 123b is grounded to the walking surface. In the first embodiment, the thumbs 103a and 103b are not used when walking on four legs. That is, the index fingers 101a and 101b and the middle fingers 102a and 102b become finger portions used when walking on four legs.

  By the way, the hand parts 209 and 212 are the thinnest links in the upper limbs. Therefore, in the first embodiment, each of the hand portions 209 and 212 has a plurality of finger portions used when walking on four legs, and by grounding the plurality of finger portions, the load is distributed, Protected. The hand portions 209 and 212 are set to postures in which the joint angles of the first finger joints of the finger portions 101a, 101b, 102a, and 102b are about 90 degrees, and the palms 104a and 104b are directed backward.

  The legged robot 100 of the first embodiment is capable of moving operations such as bipedal walking (knuckle walking), bipedal walking, tripedal walking, and climbing. The movement operation of the legged robot 100 will be described with reference to FIG. 3 (a) shows a knuckle walk, FIG. 3 (b) shows a biped walk, FIG. 3 (c) shows a three-leg walk carrying an object, and FIG. 3 (d) shows a climbing operation. In FIG. 3C, the robot has the object 501 with the right hand part 209. In FIG. 3D, the legged robot 100 climbs the bar 502 with the right hand part 209, the left hand part 212, the right foot part 215, and the left foot part 218.

  As described above, the hand portions 209 and 212 of the upper limb portions 201 and 202 that serve as support legs in the knuckle walking or the three-legged walking include the index fingers 101a and 101b and the middle fingers 102a and 102b at about 90 degrees with the first finger joints, and the hand portion 209. , 212 is bent inside. Then, the palms 104a and 104b are directed to the rear of the robot body 100A. Here, the direction in which the face of the head 206 of the robot body 100A faces is the front, and the opposite direction is the rear.

  By doing so, the hand main body 106a having the second links 110a and 115a and the palm 104a in the index finger 101a and the middle finger 102a which are the fingers of the right hand 209 can be made a part of the length of the upper limb. In addition, the hand main body 106b having the second links 110b and 115b and the palm 104b in the index finger 101b and the middle finger 102b, which are the fingers of the left hand 212, can be a part of the length of the upper limb. Therefore, even if the length of the arm portions 231 and 232 composed of the upper arm portion and the forearm portion is not so long as compared with the lower limb portions 203 and 204, it is not necessary to take an extreme forward leaning posture, and 2 Transition between walking and standing on two feet is facilitated. Also, the load on each finger 101a, 102a, 101b, 102b is reduced.

  Furthermore, the finger back surfaces 125a, 126a, 125b, and 126b on the opposite side to the grip surfaces 121a, 123a, 121b, and 123b are grounded to the walking surface. Therefore, it is possible to avoid the palms 104a and 104b and the gripping surfaces 121a, 122a, 123a, 124a, 121b, 122b, 123b, and 124b of the fingers 101a, 102a, 101b, and 102b from being damaged.

  Let's apply the above movement to indoors, which is a large part of the human living environment. Knuckle walking is most frequently used. Even on floors, carpets, tatami mats, etc. on which objects are placed, floors, steps, and stairs with different surface conditions can be moved without falling down stably. Biped walking is used for floor movements such as flooring that can be easily controlled, and for carrying things that need to be held with both hands. However, since the walking is stable, the control is complicated, and in some cases, there is a possibility of falling. In addition, when opening and closing the door, it will stand on two feet. A three-legged walk that carries an object with one hand can carry an accessory more stably than the two-legged walk in the above situation. Climbing is used when you cannot move by walking. The body is supported by gripping the limbs and moved by three-point support. An example is on a high table or desk (or vice versa).

  As shown in FIG. 3A, a foot pressure sensor 241 for detecting whether or not the right foot 215 is in contact with the walking surface is installed on the back surface of the right foot 215 for the purpose of walking control. Yes. Similarly, a foot pressure sensor 242 that detects whether or not the left foot 218 is in contact with the walking surface is installed on the back surface of the left foot 218.

  Further, in the first embodiment, in order to stably perform knuckle walking using the hand portions 209 and 212, as shown in FIG. 2, each hand portion pressure sensor is provided on each finger back surface 125a, 126a, 125b and 126b. 107a, 112a, 107b, 112b are installed. The hand pressure sensors 107a and 112a are for detecting whether or not the right hand portion 209 is in contact with the walking surface. The hand pressure sensors 107b and 112b are used to determine whether or not the left hand portion 212 is in contact with the walking surface. It is for detecting.

  These pressure sensors 107a, 112a, 107b, 112b, 241, 242 are used to obtain the center of gravity of the robot body 100A. In the first embodiment, the hand pressure sensors 107a, 112a, 107b, and 112b necessary for obtaining the center of gravity of the robot body 100A are provided on the finger back surfaces 125a, 126a, 125b, and 126b of the finger portions of the hand portions 209 and 212, respectively. It is installed. Therefore, in the gripping operation by the hand portions 209 and 212, the hand pressure sensors 107a, 112a, 107b, and 112b can be prevented from coming into contact with the gripping object, so that erroneous detection by the hand pressure sensors 107a, 112a, 107b, and 112b. Can be avoided.

  The pressure sensors 107a, 112a, 107b, 112b, 241, and 242 include an electrode provided on the surface of a pressure-sensitive conductive rubber to detect a resistance change, a sensor using a piezoresistor, a sensor using a piezoelectric body, an electrostatic sensor A capacitance detection type can be used.

  With this configuration, the joint angle between the index finger 101a, 101b and the middle finger 102a, 102b is controlled, the pressure sensors 107a, 112a, 107b, 112b on the back of the finger are grounded, and the knuckle walking is stably performed based on the signal. Can do.

  In the gripping operation, various grips can be performed using the palms 104a and 104b, the index fingers 101a and 101b, the middle fingers 102a and 102b, and the thumbs 103a and 103b. Since the number of contact points with the object to be grasped can be increased by adjusting the joint angle of the finger joint, stable grasping is possible.

  Note that the number of fingers, the number of joints, and the number of degrees of freedom are examples, and the present invention is not limited thereto. If the number, the number of joints, and the number of degrees of freedom increase, the number of grip forms increases and further manipulation and the like become possible. Further, in the gripping operation, the controllability of gripping control can be improved by providing a pressure sensor on the finger and palm gripping surfaces as in the existing multi-fingered hand.

  Next, an outline of the overall control system of the legged robot 100 will be described with reference to FIG. As shown in FIG. 4, the control system 300 as a control unit includes a controller unit 301, an upper right limb unit 302, a left upper limb unit 303, a right lower limb unit 304, a left lower limb unit 305, a head unit 306, and a trunk unit 307. Is done. Each unit is provided with a controller, and performs drive control of an internal actuator, drive / detection control of a sensor, and signal processing.

  The controller unit 301 controls each unit via a control signal to control the entire legged robot. The controller unit 301 controls each unit based on a program related to internal movement and a control signal from each unit, and moves the robot. The program related to exercise is stored in advance in the controller unit 301 and is input by communication from the outside. As a control signal interface and a communication protocol, USB (Universal Serial Bus), CAN (Controller Area Network), or the like can be used.

  In this example, each unit connected to the controller unit 301 has a built-in controller. However, each unit does not have a built-in controller, and the actuator is driven directly from the controller unit 301 and the sensor signal is detected. Is also possible.

  An outline of a control system related to finger back grounding control of the upper limb units 302 and 303 will be described with reference to FIG. The upper limb unit 302 includes an upper limb controller 401a. The upper limb controller 401a is configured by connecting hand pressure sensors 107a and 112a, an index finger actuator 404a, a middle finger actuator 405a, and a wrist actuator 406a. Similarly, the upper limb unit 303 includes an upper limb controller 401b, and is configured by connecting the hand pressure sensors 107b and 112b, the index finger actuator 404b, the middle finger actuator 405b, and the wrist actuator 406b to the upper limb controller 401b.

  Sensor signals as detection results are output from the hand pressure sensors 107a and 112a (107b and 112b) to the upper limb controller 401a (401b). A drive signal is output from the upper limb controller 401a (401b) to the index finger actuator 404a (401b), the middle finger actuator 405a (405b), and the wrist actuator 406a (406b).

  During knuckle walking, the upper limb controller 401a (401b) drives the finger actuator and the wrist actuator based on signals from the hand pressure sensors 107a and 112a (107b and 112b). Although the upper limb units 302 and 303 have other sensors and actuators, they are omitted here because they are not directly related to finger back surface grounding control.

  Next, the stability of the static walking of the legged robot 100 will be described with reference to FIG. FIG. 6 is a schematic view of the legged robot 100 as viewed from above, and schematically shows the ground contact state (supported state of the four limbs) of the four limbs 201, 202, 203, 204. FIG. 6 (a) shows a four-legged support state during knuckle walking. FIG. 6B shows a three-leg support state in a knuckle walk or a three-leg walk for carrying an object. FIG. 6 (c) shows a two-legged support state for a three-legged walking or a two-legged supported state for a two-legged walk. FIG. 6 (d) shows a single-leg support state when walking on two legs.

  The grounding portion (supporting portion) is the right finger back surface 601 (finger back surfaces 125a and 126a), the left finger back surface 602 (finger back surfaces 125b and 126b), the right foot back surface 603, and the left foot back surface 604, which are indicated by hatching. Yes. The ground contact area of the finger back surfaces 601 and 602 is smaller than the ground contact area of the foot back surfaces 603 and 604. The support polygon 605 connects the outer periphery of the ground contact portion (support portion) and is indicated by a broken line. In addition, in order to make it easy to see, the part which overlaps with a grounding part (support part) is shifted and illustrated a little. The center-of-gravity projection point 606 is a projection point on the walking surface of the center of gravity of the robot main body 100A. The control system 300 controls the posture of the robot main body 100A based on the detection results of the pressure sensors 107a, 112a, 107b, 112b, 241, and 242 so that the center-of-gravity projection point 606 is positioned within the support polygon 605 when walking still. .

  As can be seen from FIG. 6, the smaller the support legs, the smaller the support polygon 605 becomes, and it becomes difficult to control walking while maintaining the center of gravity of the robot body 100A on the support polygon 605. Therefore, the knuckle walking shown in FIG. 6 (b) is excellent in walking stability because the support polygon 605 is larger than the support polygon 605 during biped walking shown in FIG. 6 (c).

  Further, depending on the situation of the walking surface such as the floor surface (irregularity, inclination, etc.), it becomes difficult to simply obtain the center-of-gravity projection point 606 from the posture of the robot body 100A. In that case, by detecting the contact pressure of all the support legs with the pressure sensors 107a, 112a, 107b, 112b, 241, 242, the center-of-gravity projection point 606 in the knuckle walking can be easily obtained, and there are various states. Even a walking surface such as a floor surface can move stably.

  Next, walking control by quadruped walking (knuckle walking) by the control system 300 will be described with reference to FIG. Here, signals from the foot pressure sensors 241 and 242 on the soles of the lower limbs and the hand pressure sensors 107a, 112a, 107b, and 112b on the back of the upper limbs are used for walking control.

  When the sensor signal of the pressure sensor exceeds a predetermined threshold, it is detected that the grounding and the support leg have been established. Moreover, it detects that it became a free leg because the sensor signal of a pressure sensor fell below the threshold value. By controlling the posture so that the signal from the pressure sensor increases, the center-of-gravity projection point 606 is brought closer to the leg. By controlling the posture so that the signal from the pressure sensor becomes small, the center-of-gravity projection point 606 is moved away from the leg. Since the support legs are 3 or 4 in a four-leg static walking, the support polygon 605 has a shape close to a triangle or a quadrangle.

  The state in which the upper right limb 201 is a free leg and the other limbs 202, 203, and 204 are support legs is the beginning of the control cycle in the description. Hereinafter, when the robot main body 100A moves forward, the following processing is sequentially performed.

  First, the upper right limb 201 is moved forward in the traveling direction and grounded (S1). Next, the center-of-gravity projection point 606 is moved away from the left lower limb 204, and the left lower limb 204 is made a free leg (S2). Next, the left lower limb part 204 is moved from the left upper limb part 202 and grounded (S3). Next, the center-of-gravity projection point 606 is moved away from the left upper limb 202, and the left upper limb 202 is made a free leg (S4). Next, the left upper limb 202 is moved in the traveling direction and grounded (S5). Next, the center-of-gravity projection point 606 is moved away from the right lower limb 203, and the right lower limb 203 is made a free leg (S6). Next, the right lower limb part 203 is moved from the upper right limb part 201 and grounded (S7). Next, the center-of-gravity projection point 606 is moved away from the upper right limb 201, and the upper right limb 201 is made a free leg (S8). Thereafter, return to the beginning and repeat until the movement is completed.

  By using sensor signals that are detection results of the pressure sensors 107a, 112a, 107b, and 112b of the respective upper limbs, the ground control of the limbs 201, 202, 203, and 204 and the movement control of the center of gravity projection point 606 are performed. Can walk stably.

  The walking control in the three-legged walking (three-legged walking with an object) by the control system 300 will be described with reference to FIG. The handling of the pressure sensor signal is the same as in FIG. Since the support legs are 2 or 3 in the three-legged static walking, the support polygon 605 is a straight line having a width or a shape close to a triangle. In the support polygon 605 that is close to a straight line, the center-of-gravity projection point 606 is likely to go out of the support polygon 605, so the period during which there are two support legs is made as short as possible.

  A state in which an object is held in the upper right limb 201 and the other limbs 202, 203, and 204 are supporting legs is the beginning of the control cycle in the description. The following processing is performed in order. First, the center-of-gravity projection point 606 is moved away from the left lower limb 204, and the left lower limb 204 is made a free leg (S11). Next, the left lower limb 204 is moved in the traveling direction and grounded (S12). The center-of-gravity projection point 606 is moved away from the right lower limb 203, and the right lower limb 203 is made a free leg (S13). The right lower limb 203 is moved in the traveling direction and grounded (S14). The center-of-gravity projection point 606 is moved away from the left upper limb 202, and the left upper limb 202 is made a free leg (S15). The left upper limb 202 is moved in the traveling direction and grounded (S16). Thereafter, return to the beginning and repeat until the movement is completed.

  By providing a period during which the support polygon 605 is enlarged using the left upper limb 202, movement with an object can be performed more stably than walking on two legs. In addition, although the example which has an object in the upper right limb part 201 was shown, when it has an object in the left upper limb part 202, the left upper limb part 202 may be replaced with the upper right limb part 201 in the above description. Omitted.

  The hand pressure sensor may be provided only on any one of the index finger 101a and the middle finger 102a of the right hand unit 209. However, in the first embodiment, each of the index finger 101a and the middle finger 102a is provided. Is provided with a hand pressure sensor. In addition, the hand pressure sensor may be provided only on any one of the index finger 101b and the middle finger 102b of the left hand 212, but in the first embodiment, each of the index finger 101b and the middle finger 102b is provided. Is provided with a hand pressure sensor.

  Therefore, in the first embodiment, the finger joint angle is controlled in order to ground both the index finger 101a (101b) and the middle finger 102a (102b) in the hand part 209 (212) which is the three-finger hand shown in FIG. .

  Hereinafter, with reference to FIG. 9, the grounding state when the hand grounding control is performed will be described. FIG. 9A shows a state before the grounding control of the hand part, and FIG. 9B shows a state after the grounding control of the hand part. Although FIG. 9 shows the right hand part 209, the left hand part 212 operates in the same manner.

  In knuckle walking, the three fingers 101a, 102a, and 103a are placed in a posture as shown in FIG. The second finger joint 111a of the index finger 101a and the second finger joint 116a of the middle finger 102a extend. The first finger joint 109a of the index finger 101a and the first finger joint 114a of the middle finger 102a are bent inward of the hand portion 209 at about 90 degrees. In this state, the finger back surface 125a of the index finger 101a and the finger back surface 126a of the middle finger 102a are directed toward the walking surface 901 such as the floor surface. The palm is facing away from the direction of travel (the back of the hand is facing the direction of travel). By doing so, since the average distances of the two fingers 101a and 102a to the walking surface 901 are equal, the grounding control is facilitated. FIG. 9 shows an example in which the index finger 101a is grounded first. The joint angles of the index finger 101a and the middle finger 102a can be operated as long as they are not far from the above angles.

  The flow of ground control will be described with reference to FIG. The detection of the ground contact state on the back of the finger is the same as the movement control described above. The following control is performed until the upper limb is grounded and thereafter becomes a free leg. First, the controller unit 301 of the control system 300 determines whether one of the index finger 101a and the middle finger 102a is grounded based on the detection results of the hand pressure sensors 107a and 112a (S21). Next, the controller unit 301 determines whether the grounded finger is the index finger 101a or the middle finger 102a (S22). In other words, the controller unit 301 determines whether it is detected that one of the hand pressure sensors 107a and 112a is grounded on the walking surface.

  When the controller unit 301 determines that the index finger 101a is the first grounded finger part, the controller unit 301 grounds first so that the hand pressure sensor 112a of the middle finger 102a, which is the other finger part of the hand part 209, contacts the walking surface. The joint angle of the index finger 101a thus adjusted is adjusted (S23).

  Subsequently, the controller unit 301 determines whether or not the middle finger 102a is grounded (S24). If the middle finger 102a is not grounded, the controller unit 301 returns to the process of step S23. When the middle finger 102a is grounded, the controller unit 301 fixes the joint angle of the index finger 101a (S25).

  That is, when only the index finger 101a is in contact with the walking surface 901 as shown in FIG. 9A, the joint angle of the index finger 101a is adjusted, and the middle finger 102a is moved as shown in FIG. 9B. The walking surface 901 is grounded.

  In step S22, when the controller unit 301 determines that the middle finger 102a is the first grounded finger, the controller unit 301 first grounds the other finger so that the hand pressure sensor 107a of the index finger 101a is grounded on the walking surface. The joint angle of the middle finger 102a thus adjusted is adjusted (S26).

  Subsequently, the controller unit 301 determines whether or not the index finger 101a is grounded (S27). If the index finger 101a is not grounded, the controller unit 301 returns to the process of step S26. When the index finger 101a is grounded, the controller unit 301 fixes the joint angle of the middle finger 102a (S28). Subsequent to steps S25 and S28, the controller unit 301 determines whether the index finger 101a and the middle finger 102a are not in contact with each other, that is, whether or not they are separated from the walking surface such as the floor surface (S29). The process of step S29 is repeated until the index finger 101a and the middle finger 102a are separated from the walking surface. When the controller unit 301 stops grounding, the joint angle of the finger portions 101a and 102a is returned to the angle before the ground control (S30).

  By performing the above grounding control, the two fingers 101a and 102a can be reliably grounded and the load applied to the upper limb 201 can be supported almost evenly by the two fingers 101a and 102a. The burden on the portions 101a and 102a is reduced, and damage and the like can be prevented. In addition, since the individual finger portions 101a and 102a can be made thin, it is possible to improve the functions of gripping and operating using fingers.

[Second Embodiment]
Next, a legged robot according to a second embodiment of the present invention will be described. Since the configuration of the robot body is the same as that of the first embodiment, description will be made using the same reference numerals. In the second embodiment, the control operation of the control system that is the control unit is different.

  FIG. 11 is a diagram illustrating a grounding state when the grounding control of the hand portion of the legged robot according to the second embodiment is performed. FIG. 11A shows a state before the grounding control of the hand part, and FIG. 11B shows a state after the grounding control of the hand part. Although FIG. 11 shows the right hand part 209, the left hand part 212 operates in the same manner.

  In the second embodiment, the angle of the wrist 105a (the hand part 209 with respect to the arm part 231) is controlled in order to ground both the index finger 101a and the middle finger 102a of the hand part 209. By changing the angle of the wrist 105a, the finger back surface 125a of the index finger 101a and the finger back surface 126a of the middle finger 102a are both grounded.

  The flow of ground control will be described with reference to FIG. The detection of the ground contact state on the back of the finger is the same as the movement control described above. The following control is performed until the upper limb is grounded and thereafter becomes a free leg. First, the controller unit 301 of the control system 300 determines whether one of the index finger 101a and the middle finger 102a is grounded based on the detection results of the hand pressure sensors 107a and 112a (S31). Next, the controller unit 301 determines whether the grounded finger is the index finger 101a or the middle finger 102a (S32). In other words, the controller unit 301 determines whether it is detected that one of the hand pressure sensors 107a and 112a is grounded on the walking surface.

  When the controller unit 301 determines that the index finger 101a is the first grounded finger part, the wrist 105a (the hand pressure sensor 112a of the middle finger 102a, which is the other finger part of the hand part 209, contacts the walking surface. The angle of the hand part 209) with respect to the arm part 231 is adjusted. Specifically, the wrist 105a is rotated in the direction in which the index finger 101a approaches the arm 231 (S33).

  Subsequently, the controller unit 301 determines whether or not the middle finger 102a is grounded (S34). If the middle finger 102a is not grounded, the controller unit 301 returns to the process of step S33. When the middle finger 102a is grounded, the controller unit 301 fixes the angle of the wrist 105a (S35).

  That is, as shown in FIG. 11A, when only the index finger 101a is in contact with the walking surface 901, the angle of the wrist 105a is adjusted, and the middle finger 102a is walked as shown in FIG. 11B. The surface 901 is grounded.

  If the controller unit 301 determines in step S32 that the middle finger 102a is the finger that has been grounded first, the wrist 105a (the finger pressure sensor 107a of the index finger 101a that is the other finger is grounded to the walking surface. The angle of the hand part 209) with respect to the arm part 231 is adjusted. Specifically, the wrist 105a is rotated in a direction in which the middle finger 102a approaches the arm portion 231 (S36).

  Subsequently, the controller unit 301 determines whether or not the index finger 101a is grounded (S37). If the index finger 101a is not grounded, the controller unit 301 returns to the process of step S36. When the index finger 101a is grounded, the controller unit 301 fixes the joint angle of the middle finger 102a (S35).

  Subsequent to step S35, the controller unit 301 determines whether or not the index finger 101a and the middle finger 102a are not in contact with each other, that is, whether they are separated from the walking surface such as the floor surface (S38). The process of step S38 is repeated until the index finger 101a and the middle finger 102a are separated from the walking surface. If the controller unit 301 stops grounding, the angle of the wrist 105a is returned to the angle before the ground control (S39).

  By performing the above grounding control, the two fingers 101a and 102a can be reliably grounded and the load applied to the upper limb 201 can be supported almost evenly by the two fingers 101a and 102a. The burden on the portions 101a and 102a is reduced, and damage and the like can be prevented. In addition, since the individual finger portions 101a and 102a can be made thin, it is possible to improve the functions of gripping and operating using fingers.

  Although the present invention has been described based on the first and second embodiments, the present invention is not limited to this. In the above-described embodiment, the case where two fingers are grounded with a three-finger hand has been described. However, the present invention can be applied to other forms of hands. For example, three fingers may be grounded with a four finger hand. Further, there may be one finger to be grounded. In this case, the control processing shown in FIGS.

  Further, in the above-described embodiment, the case where the joint angle of the finger part is controlled or the wrist angle is controlled in the grounding control has been described. It is also possible to do this.

DESCRIPTION OF SYMBOLS 100 ... Leg type robot, 100A ... Robot main body, 101a, 101b ... Index finger (finger part), 102a, 102b ... Middle finger (finger part), 106a, 106b ... Hand main part, 107a, 112a ... Hand part pressure sensor, 107b, 112b: Hand pressure sensor, 121a, 121b, 123a, 123b ... Grasping surface, 125a, 125b, 126a, 126b ... Finger back surface, 201, 202 ... Upper limb, 203, 204 ... Lower limb, 205 ... Trunk, 209, 212 ... Hand part, 215, 218 ... Foot part, 241, 242 ... Foot pressure sensor, 300 ... Control system (control part)

Claims (5)

A robot body having a trunk, two lower limbs connected to the trunk, and two upper limbs connected to the trunk, and each lower limb is on a walking surface during walking Each of the upper limbs has an arm and a hand that is connected to the arm and is capable of gripping an object to be gripped. In a legged robot capable of walking on four legs using the two lower limbs and the two upper limbs,
A hand pressure sensor for detecting whether or not each of the hands touches the walking surface;
A foot pressure sensor that detects whether or not each of the feet touches the walking surface;
A control unit for determining the center of gravity of the robot body from the detection results of the hand pressure sensor and the foot pressure sensor, and controlling the posture of the robot body,
Each hand part has a finger part that bends the finger joint when walking on four legs and grounds the back of the finger opposite to the gripping surface to the walking surface,
The leg-type robot, wherein the hand part pressure sensor is installed on a finger back surface of a finger part of each hand part. A robot body having a trunk, two lower limbs connected to the trunk, and two upper limbs connected to the trunk, and each lower limb is on a walking surface during walking Each of the upper limbs has an arm part and a hand part that is connected to the arm part and is capable of gripping an object to be grasped, and is capable of walking on two legs using the two lower limb parts. In a legged robot capable of walking on four legs using the two lower limbs and the two upper limbs,
A hand pressure sensor for detecting whether or not each of the hands touches the walking surface;
A foot pressure sensor that detects whether or not each of the feet touches the walking surface;
A control unit for determining the center of gravity of the robot body from the detection results of the hand pressure sensor and the foot pressure sensor, and controlling the posture of the robot body,
Each hand part has a plurality of finger parts that bend the finger joints when walking on four legs and ground the finger back opposite to the gripping surface to the walking surface,
The leg-type robot, wherein the hand part pressure sensor is installed on a finger back surface of each finger part of each hand part.   When the control unit detects that the ground is touched on the walking surface by any one of the hand pressure sensors installed on the finger back surface of each finger part of the hand part, The leg according to claim 2, wherein a joint angle of the finger part grounded at the tip of the hand part is adjusted so that a hand pressure sensor installed on a finger back surface of the finger part contacts the walking surface. Type robot.   When the control unit detects that the ground is touched on the walking surface by any one of the hand pressure sensors installed on the finger back surface of each finger part of the hand part, The legged robot according to claim 2, wherein an angle of the hand part with respect to the arm part is adjusted so that a hand part pressure sensor installed on a finger back surface of the finger part contacts the walking surface.   The legged robot according to any one of claims 1 to 4, wherein the hand portion has a palm directed backward when walking on four legs.

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