JP2005088189A - Program for generating motion pattern of robot, motion pattern generating device, and robot using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adopt a state of a knee joint part being completely stretched like human walking action during the walking action. <P>SOLUTION: In a program for generating a motion pattern of a robot, one of joint angles on at least one of leg parts is arbitrarily preset, and a joint angle except the preset joint angle is obtained by adding change to at least a part of a toe track and/or a waist track based on a prescribed restraint condition in a state where the toe track which is the track of a toe part, and the waist track which is the track of a waist part, are temporarily set, and thereafter calculating reverse kinematic analysis concerning the arbitrary toe track and/or waist track. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a robot motion pattern creation program, a motion pattern creation device, and a robot using the same, and more particularly, to a legged robot such as a bipedal walking robot. The present invention relates to a robot motion pattern creation program, a motion pattern creation device, and a robot using the same.

Most recent bipedal robots are arranged on a pair of left and right legs with a plurality of joints, a pair of left and right toes connected to the lower ends of these legs, and the upper ends of the legs. The lower limb portion is provided with a lower waist portion, and the lower limb portion is set to 6 degrees of freedom on the left and right. Each joint angle in each joint part is obtained by calculating an inverse kinematic solution with 6 degrees of freedom regardless of a standing leg or a free leg based on the relative position and posture of the toe part and the waist part. In this case, when the knee joint part is fully extended, that is, when the leg regions on both the upper and lower sides sandwiching the knee joint part are substantially straight with each other, the angular velocity of the knee joint part becomes an infinite point. Therefore, when calculating the inverse kinematic solution, adjustment is made so that the walking pattern is created within a range in which the knee joint portion does not extend completely (see Non-Patent Documents 1 and 2).
Hirose Shigeo, “Robot Engineering (Revised Edition)-Vector Analysis of Mechanical Systems”, 1st Edition, Hanafusa, December 1987, p. 157-187 Yoshikawa Tsuneo, “Robot Control Basics”, First Edition, Corona, November 1988, p. 11-68

  However, in the conventional biped robot, for the purpose of avoiding the singular point, it is necessary to always perform a walking motion with the knee joint bent, and unlike a human walking motion, The state where the joint part is fully extended cannot be taken as a part of the walking motion. As a result, the torque acting on the knee joint portion increases and energy consumption increases, and the movable range is narrower than that of humans.

  The present invention has been devised by paying attention to such inconveniences, and an object of the present invention is to create an exercise pattern in which the angles of some joint portions constituting the leg portion can be freely set without limitation. In particular, a motion pattern creation program for a robot, and a motion pattern creation device and a robot using the same, which can adopt a state in which the knee joint portion is completely extended like a walking motion of a human or the like during a walking motion Is to provide.

(1) In order to achieve the above object, a plurality of leg portions including a plurality of joint portions, a toe portion continuous to the lower end side of the leg portion, a waist portion continuous to the upper end side of the leg portion, and a predetermined exercise For a legged robot provided with a control device that controls the operation of each joint based on a pattern, in a program for creating the movement pattern by a computer,
In a state in which a part of the joint angle in at least some of the legs is arbitrarily set in advance, and a foot trajectory that is the trajectory of the foot tip and a waist trajectory that is the trajectory of the waist are provisionally set, Based on a predetermined restraint condition, a change is made to at least a part of the toe trajectory and / or the waist trajectory, and by calculating an inverse kinematic solution related to any of the toe trajectory and / or the waist trajectory in advance, A configuration is adopted in which the joint angle excluding the set joint angle is obtained.

(2) Further, based on a predetermined motion pattern, a plurality of leg portions including a hip joint portion and a knee joint portion, a foot portion continuous to the lower end side of each leg portion, a waist portion continuous to the upper end side of the leg portion, and With respect to a legged robot provided with a control device that controls the operation of each joint part, a program for creating the motion pattern with a predetermined computer,
In the state where various conditions including a foot tip trajectory that is the foot tip trajectory, a 5-degree-of-freedom waist trajectory that is the trajectory of the waist excluding coordinates in the height direction, and knee joint angles on the stance side are initially set,
Determining whether each leg is a standing leg or a free leg for a predetermined time;
By calculating an inverse kinematic solution from the foot tip trajectory, the 5-degree-of-freedom hip trajectory, and the knee joint angle for each leg determined to be a stance leg, each of the leg side excluding the knee joint angle is calculated. A step of determining the stance side to obtain the joint angle and the height of the hip joint,
For the leg determined to be a free leg, an inverse kinematic solution is obtained from the position and posture of the hip joint on the stance side determined in the stance side determination step, the foot tip trajectory and the 5-degree-of-freedom waist trajectory. By calculating, the free leg side determining step for obtaining each joint angle on the free leg side,
The computer is also configured to execute.

(3) Here, in a state where the physical quantity limit area related to the operation of the knee joint is further initialized,
In the step of determining the stance side, the transition from the free leg to the stance leg is performed when the physical quantity is out of the limit area when the limb is displaced to a preset knee joint angle on the stance side. After correcting to the knee joint angle, by calculating an inverse kinematic solution from the corrected knee joint angle, the toe trajectory, and the 5-degree-of-freedom waist trajectory, each joint angle and hip joint on the stance side It is preferable to adopt a configuration in which the height of the is determined.

(4) In addition, in a state where the physical quantity limit area related to the motion of the knee joint is further initialized,
In the step of determining the free leg side, when the physical quantity of the knee joint part on the free leg side is outside the restriction area, the knee joint angle on the free leg side is fixed to a predetermined value where the physical quantity is within the restriction area, A configuration is preferably employed in which each joint angle on the free leg side is determined by calculating an inverse kinematic solution that also takes into account the movement of the waist.

(5) Further, a plurality of leg portions including knee joint portions, a foot tip portion connected to the lower end side of each of the leg portions, a waist portion continuous to the upper end side of the leg portion, and each of the above-mentioned based on a predetermined walking pattern For a legged robot provided with a control device for controlling the operation of the joint part, in a program for creating the movement pattern by a predetermined computer,
Various conditions including a foot tip trajectory that is the foot tip trajectory, a four-degree-of-freedom waist trajectory that is a trajectory of the waist except for the posture and height coordinate in the roll direction, and various knee joint angles are initially set. In the state
By using the fact that the height of the waist calculated from the foot tip, the 4-degree-of-freedom waist track, and the knee joint angles on the basis of each foot is mutually the same, Calculating the posture and height coordinates by calculation;
Each joint excluding a preset knee joint angle is calculated by calculating an inverse kinematic solution from the foot trajectory, the knee joint angles, and the waist trajectory including the posture in the roll direction and the coordinates in the height direction. The step of determining the angle,
The computer is configured to be executed.

  (6) Further, in order to achieve the above object, the exercise pattern creation device according to the present invention stores the exercise pattern creation program, and creates the exercise pattern based on the exercise pattern creation program. The composition is taken.

  (7) Furthermore, the robot according to the present invention has a configuration in which the motion pattern creation program is stored, and the motion pattern creation device that creates the motion pattern based on the motion pattern creation program is provided. ing.

  In this specification, “standing leg” means a leg part that is in contact with the ground, and “free leg” means a leg part that is not in contact with the ground.

  In this specification, “X axis”, “Y axis”, and “Z axis” are axes in the coordinates shown in FIG. 1, that is, axes extending in the front-rear direction of the biped robot. It means an axis extending in the left-right direction and an axis extending in the same vertical direction.

  Further, the “roll direction” means the rotation direction around the X axis, the “pitch direction” means the rotation direction around the Y axis, and the “yaw direction” means around the Z axis. Means the direction of rotation.

  The “joint angle” means the rotation angle of the joint part.

  Furthermore, the “walking pattern” means data on the lower limb trajectory in which the rotation angle at each joint portion is determined in time series, and is a kind of movement pattern including other movements.

  Further, the “restricted area” means a physical quantity range in which the output of the actuator that operates the joint portion can be properly maintained.

  According to the configurations of (1), (6) and (7) above, at least a part of the foottip trajectory and / or the waist trajectory temporarily set by using a constraint condition by arbitrarily setting a part of joint angles. Since the remaining joint angles are determined using inverse kinematics, there are no restrictions such as avoiding singularities of the joint angles, making them suitable for various types of movements performed by humans and others. An exercise pattern can be obtained.

  In particular, according to the configuration of (2), the knee joint angle is calculated as an inverse kinematic solution by setting the knee joint angle in advance on the stance side instead of setting the coordinate in the height direction of the hip joint. Therefore, it is possible to freely set a state in which the knee joint portion is fully extended. Therefore, it is possible to adopt a state in which the knee joint portion is fully extended in the course of the walking motion for a biped walking robot or the like, and a walking motion like a human can be realized.

  Here, with the configuration as described in (3) above, the actuator constituting the knee joint portion on the stance leg side can be driven within the specified range, and the runaway of the robot can be prevented.

  Also, with the configuration (4), the actuator that constitutes the knee joint portion on the free leg side can be driven within the specified range, and the robot can be prevented from running away.

  Furthermore, by adopting the configuration of (5) above, the remaining joint angles are calculated with the knee joint angles set in advance throughout the stance phase and the swing phase, so A sudden change in angular velocity of the knee joint at the time of switching between the period and the swing leg period is suppressed, and a smoother walking motion can be realized. Further, since the knee joint angle is set in advance, it is possible to cause the knee joint portion to perform an effective operation, and as a result, it is possible to increase the stride of the robot. Also, it is possible to generate a smooth pattern for the motion patterns of the joints excluding the knee joint, and it is possible to create a more stable motion pattern for the entire robot.

Embodiments of the present invention will be described below with reference to the drawings.
[First embodiment]

  FIG. 1 is a conceptual diagram of a robot system to which the present invention is applied. In this figure, the robot system 10 creates a biped robot 11 as a legged robot set to 6 degrees of freedom for one leg and a walking pattern that is one of the motion patterns of the biped robot 11. And a computer 12 as an exercise pattern creation device.

  The biped robot 11 includes a pair of left and right leg portions 14, 14, a pair of left and right foot tip portions 15, 15 connected to the lower end sides of the leg portions 14, 14, and an upper end side of the leg portions 14, 14. A continuous waist 16 and a control device 17 disposed on the waist 16 are provided.

  The leg portions 14, 14 have the same structure on the left and right and are arranged symmetrically. The leg portion 14 includes an ankle joint portion 19 continuous with the upper end side of the toe portion 15, a hip joint portion 20 continuous with the lower end side of the waist portion 16, and a leg body 21 extending between the ankle joint portion 19 and the hip joint portion 20. And a knee joint portion 23 provided in the middle of the leg body 21.

  The ankle joint portion 19 includes an ankle roll mechanism 25 that allows the toe portion 15 to rotate in the roll direction relative to the leg body 21, and an ankle that enables the toe portion 15 to rotate in the pitch direction relative to the leg body 21. And a pitch mechanism 26.

  The hip joint 20 includes an upper leg roll mechanism 27 that allows the leg 21 to rotate in the roll direction with respect to the waist 16, and an upper leg pitch mechanism 28 that allows the leg 21 to rotate in the pitch direction relative to the waist 16. And an upper leg yaw mechanism 29 that allows the leg body 21 to rotate in the yaw direction with respect to the waist 16.

  The leg body 21 includes an upper leg 21 </ b> A located above the knee joint portion 23 and a lower leg 21 </ b> B located below the knee joint portion 23.

  The knee joint portion 23 includes a knee pitch mechanism 30 that connects the upper leg 21A and the lower leg 21B so as to be relatively rotatable in the pitch direction.

  Each of the mechanisms 25 to 30 includes an actuator such as a motor (not shown) and a belt, a pulley, a link, and the like connected to the actuator, and is configured to enable each operation described above by driving the actuator. It should be noted that the configuration here is substantially the same as that employed in a known bipedal robot, and detailed description is omitted and the structure is simplified and illustrated.

  Based on the walking pattern created by the computer 12, that is, based on the data in which the joint angles at the joints 19, 20, and 23 are determined in time series, the control device 17 23 controls the driving of the actuators of the mechanisms 25-30. Here, the walking pattern is created by the computer 12, recorded on a predetermined recording medium, and stored in the control device 17 by setting the recording medium in the control device 17.

  The computer 12 stores in advance a program that makes it possible to create the walking pattern after performing a predetermined initial setting. By executing the program, a desired one corresponding to the initial setting is set for the biped walking robot 11. The walking pattern that realizes the walking motion is created. As shown in FIG. 2, the initial setting here is an angular velocity (hereinafter referred to as “knee joint”) of a foot tip trajectory setting unit 33, a waist trajectory setting unit 34, a knee joint angle setting unit 35, and a knee joint unit 32. (Referred to as “angular velocity”).

  In the foot tip trajectory setting unit 33, the trajectory (foot tip trajectory) of the foot tip portion 15 is set as follows. First, the distance between the foot tips 15 in the X-axis direction and the Y-axis direction and the height of the midpoint between the ground tips of the foot tips 15 for each of the left and right foot tips 15 when the both feet are in the ground contact state. Each step is arbitrarily designated and input to the computer 12. Then, by calculation by the computer 12, the foot trajectory is obtained by complementing with a fifth or sixth function from the first coordinates of the left and right foot toe portions 15 for each step, the coordinates of the intermediate point, and the last coordinates. . That is, here, at every predetermined time interval (hereinafter referred to as “layer”), the coordinates (positions) and roll directions of the left and right foot tips 15, 15 in the X-axis direction, Y-axis direction, and Z-axis direction, The postures in the pitch direction and the yaw direction are required.

  The waist trajectory setting unit 34 determines that the trajectory of the waist portion 16 (5-degree-of-freedom waist trajectory) excluding the coordinates in the Z-axis direction (height direction) based on the toe trajectory obtained as described above. It is obtained by calculation. That is, for each layer, the coordinates of the waist 16 in the X-axis and Y-axis directions are determined so that the center of gravity of the waist 16 passes through the midpoint between the centers of the left and right toe portions 15. At this time, a predetermined dummy numerical value is temporarily set as the coordinate in the height direction of the waist 16 in terms of computer processing. Further, the postures of the waist 16 in the roll direction, pitch direction, and yaw direction are set in a horizontal state so as not to incline with respect to the ground plane. Note that the posture of the waist 16 in the roll direction, pitch direction, and yaw direction can be arbitrarily set by the user.

In the knee joint angle setting unit 35, the rotation angle (knee joint angle) of the knee joint part 23 on the stance side is set based on the following equation where the time from the free leg to the standing leg is set to t = 0.
Here, θ represents the knee joint angle, and T represents the walking speed. In this embodiment, θ = 0 (deg) is set when the knee joint 23 is fully extended so that the upper leg 21A and the lower leg 21B are in a substantially straight state, and the upper leg 21A and the lower leg 21B are substantially overlapped with each other. When the knee joint 23 is fully bent, θ = −180 (deg) and T = 0.96 s / step.

  In the knee joint angular velocity limit area setting section 36, a physical quantity limit area related to the operation of the knee joint section 23 is set. Specifically, the restriction region here is set with the maximum value of the allowable angular velocity as the upper limit in terms of the performance of the actuator constituting the knee joint portion 23. In this embodiment, the maximum value of the angular velocity is set to about 100 deg / sec.

  After the initial setting as described above, a walking pattern is obtained according to the following procedure in the walking pattern creation program. That is, here, for each layer, through steps S1 to S10 in FIG. 2, the joint angles that are the rotation angles in the mechanisms 25 to 30 are determined, and the joint angles in all layers are determined (step S11). A walking pattern in which each joint angle is time-series is generated (step S12).

  Specifically, first, in step S1, it is determined whether each leg portion 14 or 14 in the target layer is a standing leg or a free leg from a preset foot tip trajectory.

  Next, in step S2, the joint angles of the joint portions 19 and 20 other than the knee joint portion 23 are calculated for the leg portion 14 determined to be a standing leg in step S1. That is, here, 5 freedoms excluding the knee joint portion 23 from the initially set relative positions and postures of the toe portion 15 and the waist portion 16 (restraint conditions) and the initially set knee joint angle on the stance side. The inverse kinematics solution of the degree is calculated, and each of the joint angles on the stance side excluding the knee joint portion 23 and the coordinates in the height direction (Z-axis direction) of the hip joint portion 20 on the stance side corresponding to the height of the waist portion 16 are obtained. The previous temporary setting value is changed. At this time, whether the knee joint angular velocity required for displacement to the knee joint angle on the stance side set as the initial position is within the restriction range as in the case where the front layer is a free leg and the target layer is shifted to a stance leg? It is determined whether or not (step S3). Here, if the knee joint angular velocity is within the restriction range, the inverse kinematic solution obtained in step S2 is set as the determined value as the height of the hip joint 20 (step S4). On the other hand, when the knee joint angular velocity exceeds the upper limit of the restriction region, the value of the knee joint angle obtained by the equation (1) is corrected so that the knee joint angular velocity becomes a predetermined value within the restriction region ( Step S5). Then, the process returns to step S2 again, and the coordinate in the height direction of the hip joint 20 is calculated again by inverse kinematics using the corrected knee joint angle, and the calculated value is set as the determination value (step) S4). In the above, steps S2 to S5 constitute a stance side determination step.

  Thereafter, in step S6, the rotation angles (joint angles) of all joint parts 19, 20, and 23 are calculated for the leg part 14 determined to be a free leg in step S1. That is, here, 6 positions are determined from the initially set positions and postures of the toe portion 15 and the waist portion 16 and the coordinates in the height direction (Z-axis direction) of the hip joint portion 20 on the stance side determined in step S4. The inverse kinematic solution of the degree is calculated, and each joint angle on the free leg side is obtained. At this time, the movement of the waist 16 in the roll direction is not performed, and it is assumed that the height of the hip joint 20 is the same on the standing leg side and the free leg side (restraint condition). Then, it is determined whether or not the knee joint angular velocity on the free leg side falls within a preset limit region with the displacement of the knee joint portion 23 from the front (step S7). Here, if the knee joint angular velocity is within the restriction range, each joint angle on the free leg side calculated in step S6 is set as a determined value, and all joint angles on the standing leg side and the free leg side are determined (step S8). .

  On the other hand, when the knee joint angular velocity exceeds the upper limit of the restriction region, the knee joint angle on the free leg side is fixed so that the knee joint angular velocity becomes a predetermined value within the restriction region (step S9). Then, from the knee joint angle on the free leg side fixed in step S9, the position and posture of the toe portion 15 and the waist portion 16, and the position and posture of the hip joint portion 20 on the stance leg side, the hip joint portion 20 on the stance leg side is determined. Each joint angle on the free leg side is calculated anew by inverse kinematics assuming that the waist 16 rotates in the roll direction at the center (step S10). That is, here, in addition to each joint angle on the free leg side, the rotation angle in the roll direction at the hip joint portion 20 on the stance leg side related to the waist movement is calculated, and the rotation angle in the roll direction set by the initial setting is changed. Then, the joint angles on the standing leg side and the free leg side are finally determined (step S8). In the above, steps S6, S7, S9, and S10 constitute a free leg determination step.

  Thereafter, in step S11, it is determined whether or not the calculation for one walking cycle is completed. As a result, if the calculation for one walking cycle is not completed, the joint angles on the standing leg side and the free leg side are determined in the same manner as described above in steps S1 to S10 for the next layer. On the other hand, if it is determined that the joint angles in all layers have been determined, a walking pattern in which the data of the joint angles in each layer is time-series is completed (step S12).

  The walking pattern created in this way is created based on the waist trajectory arbitrarily set by the waist trajectory setting unit 34, and does not take into account the mass of the robot 11 and the acting moment. Sometimes the robot 11 may fall. Therefore, in order to avoid the robot 11 from falling during walking, a program for correcting the walking pattern is created as described below after creating a walking pattern based on the initially set waist trajectory as described above. Executed. This program is subjected to various calculations and the like according to the procedure shown in FIG. 3, and is finally corrected to a walking pattern so that the robot 11 does not fall during walking.

  That is, after the walking pattern is calculated as described above based on the waist trajectory arbitrarily set by the waist trajectory setting unit 34 (step S100), a known ZMP (zero moment) set in advance is calculated from the walking pattern. (Point) The moment generated by the walking of the robot 11 on the trajectory is calculated (step S101). Here, the ZMP trajectory is set by the ZMP trajectory setting unit 37 in the computer 12 so that the ZMP is located at the ground contact portion of the toe portion 15 based on the toe trajectory set by the toe trajectory setting unit 33. The

  Next, based on the moment calculated in step S101, the coordinates of the waist 16 in the X-axis and Y-axis directions are corrected so that the robot 11 does not fall (step S102). In other words, an approximate solution of the moment compensated waist trajectory is obtained from the linearized biped robot model using fast Fourier transform and inverse fast Fourier transform. Note that values set by the waist trajectory setting unit 34 are used as they are for the posture of the waist part 16 in the roll direction, pitch direction, and yaw direction.

  Then, using the corrected waist trajectory with moment compensation, a walking pattern with moment compensation is created by the same calculation as in step S101 (step S103).

  Next, the moment on the ZMP trajectory is calculated from the walking pattern subjected to moment compensation by the same calculation as in step S101, and a moment error from the set ZMP is obtained (step S104).

  The obtained moment error is compared with the allowable error moment preset by the allowable error moment setting unit 38 (step S105). As a result, if the moment error is smaller than the allowable error moment, the last obtained walking pattern is determined as the walking pattern of the robot 11 and output to the storage medium (step S106). On the other hand, if the moment error is larger than the allowable error moment, the moment error is added to the moment calculated in step S101, and recalculation in step S102 and subsequent steps is performed. Steps S101 to S105 are repeated until the moment error becomes smaller than the allowable error moment.

Therefore, according to the first embodiment as described above, the knee joint angle on the stance side is not obtained by inverse kinematics, but the knee joint angle on the stance side is set in advance, and the corresponding amount is set in the height direction of the waist 16. Therefore, the knee joint 23 on the stance side can be completely extended, and the robot 11 can be made to perform a walking motion that is very close to a human walking motion. As a result, the burden on the knee joint portion 23 is reduced, the miniaturization of the actuator constituting the knee joint portion 23 is promoted, and the walking operation with less energy is enabled due to the weight reduction of the robot. As a result, the movable range can be expanded as compared with the conventional type.
In addition, even when the knee joint portion 23 on the free leg side is completely extended or in the vicinity thereof, the hip movement of the waist portion 16 is used in combination so that the toe portion 15 is positioned according to the target value. Therefore, it is possible to create a walking pattern according to the initially set foot leg trajectory on the free leg side.

  In addition to the angular velocity described above, the physical quantity constituting the restricted area of the knee joint section 23 may be a physical quantity related to the output of the actuator, such as an angle, an angular acceleration, and an electric current value of the actuator that operates the knee joint section 23. Anything is fine.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, the same reference numerals are used for the same or equivalent components as in the first embodiment, and the description is omitted or simplified.

  In this embodiment, the walking pattern calculation method applied in steps S100 and S103 is changed from that in the first embodiment. That is, in this embodiment, the knee joint angle that is continuous in both the stance phase and the free leg phase is set so that the knee joint portion 23 operates smoothly when switching between the stance leg and the free leg. It is characterized in that the joint angle in each layer is obtained with the same algorithm without distinction.

  In this embodiment, a walking pattern is created by the procedure shown in FIG. The initial setting here is performed by the toe trajectory setting unit 33, the waist trajectory setting unit 34, and the knee joint angle setting unit 35.

  In the foot tip trajectory setting unit 33 of the present embodiment, the foot tip trajectory, that is, the X-axis direction, the Y-axis direction, and the Z-axis of the left and right foot portions 15, 15 for each layer in the same procedure as in the first embodiment. The coordinates (position) of the direction and the posture in the roll direction, the pitch direction, and the yaw direction are obtained.

  On the other hand, in the waist trajectory setting unit 34, the trajectory (four degrees of freedom) of the waist part 16 excluding the coordinate in the Z-axis direction (height direction) and the posture in the roll direction based on the foot trajectory obtained by the foot tip trajectory setting unit 33. Waist trajectory) is obtained by calculation of the computer 12. That is, in this embodiment, a waist trajectory having 4 degrees of freedom, which is 1 degree of freedom less than that of the first embodiment, is set. Here, predetermined dummy numerical values are provisionally set for the coordinates of the waist 16 in the height direction and the posture in the roll direction in terms of computer processing.

  In the knee joint angle setting unit 35 of the present embodiment, the angles of the knee joint portions 23 and 23 are set continuously throughout the stance phase and the swing phase. That is, in this embodiment, as shown in FIG. 5, the relationship between the elapsed time and the knee joint angle is set to be a cubic spline curve relationship in the one knee joint portion 23. The relationship between the elapsed time and the knee joint angle is not limited to the relationship of the cubic spline curve, but is a curve that can realize smooth movement, that is, continuous even when it is differentiated twice and becomes an acceleration term. Any curve may be used as long as it is a curve (for example, a SIN curve).

  After the initial setting as described above, a walking pattern is created according to the following procedure. That is, for each layer, the joint angles of the mechanisms 25 to 30 are obtained through steps S200 to S203 of FIG. 4, and when the joint angles are obtained for all layers, the walking is performed by chronologically categorizing the joint angles. A pattern is created (step S204).

Specifically, first, the toe trajectory set by the toe trajectory setting unit 33, the four-degree-of-freedom hip trajectory set by the hip trajectory setting unit 34, and the left and right both set by the knee joint angle setting unit 35 From the joint angles of the knee joint portions 23, 23, the posture (roll angle) of the lumbar portion 16 that has not yet been determined is determined by the following calculation.
The position P _wl of the waist 16 with respect to the left toe 15 is
It is represented by
here,
Similarly, the position P _wr of the waist 16 _relative to the right foot part 15 is:
It is represented by

While it is conceivable that the foot tip portion 15 of the robot 11 takes various postures during walking, in this embodiment, the foot tip portion 15 is always kept level with respect to the ground contact surface of the foot tip portion 15. The postures of the left and right foot portions 15, 15 are respectively expressed by the following equations.
From the above formulas (2), (3), and (4), the height of the waist 16 calculated with the left leg link and the height of the waist 16 calculated with the right leg link are as follows. .
At this time, the position and posture of the waist 16 have a constraint that the reference value must be the same regardless of whether the reference is left or right. Therefore, the above equation (5) = the above equation (6). To establish.
Here, since the posture matrix (bx, by, bz) in the roll direction is a unit vector, the relationship of bx ² + by ² + bz ² = 1 is established, and the posture in the yaw direction is initially set. Equation (7) is a one-variable equation, whereby the posture (bx, by, bz) in the roll direction is obtained, and the above-described temporary setting value is changed. For the meaning of the other parameters in equation (7), refer to FIG.

  And the height of the waist | hip | lumbar part 16 is calculated | required using the said Formula (5) or (6), and the temporary setting value mentioned above is changed (step S201).

  After performing the above calculation, the positions and postures of the toe portion 15 and the waist portion 16 are determined. Similar to the case of the first embodiment, by calculating the inverse kinematic solution, the joint angles of both legs excluding the knee joint angle are calculated. Is obtained (step S202).

  Then, it is determined whether or not the calculation for all the walking cycles has been completed (step S203). As a result, if the calculation for one walking cycle has not been completed, the joint angles of both legs excluding the knee joint angle are also obtained for the next layer through steps S200 to S202 as described above. On the other hand, if it is determined that each joint angle has been obtained in all layers, a walking pattern in which the data of each joint angle in each layer is time-series is generated (step S204).

  The walking pattern created in this way is corrected to a walking pattern in which the robot 11 does not fall during walking in the procedure shown in FIG. 3 as in the first embodiment.

  According to the second embodiment, since the walking pattern is obtained in a state in which a knee joint angle that is a series in both the stance phase and the swing phase is set in advance, the knee joint portion is switched at the time of switching between the stance phase and the swing phase. 23 can be suppressed, a smooth transition operation between the stance phase and the swing phase can be realized, and the stride can be increased to obtain a walking motion closer to that of a human.

  In each of the above embodiments, the walking pattern created by the computer 12 is stored in the control device 17 via a recording medium. However, the walking pattern is transferred from the computer 12 to the control device 17 by wired communication or wireless communication. May be transmitted. The computer 12 can also be provided on the biped walking robot 11 side by being integrated with the control device 17 or the like.

  Further, the ankle joint portion 19 may be further provided with an ankle yaw mechanism that allows the foot tip portion 15 to rotate in the yaw direction with respect to the leg body 21.

  Furthermore, in each of the above-described embodiments, the example in which the present invention is applied to the biped robot 11 has been illustrated and described. However, the present invention is not limited to this, and a multi-legged walking leg that is simulated by an animal type or an insect. It can also be applied to a robot.

  In addition, the algorithm of each of the above embodiments allows the knee joint portion 23 to move freely. However, the initial setting joint portion in the algorithm may be replaced with the ankle joint portion 19 or the hip joint portion 20 and applied. Is possible. That is, according to the algorithm in this case, the joint angle of the other joint portion is obtained using the constraint condition in the state where the ankle joint portion 19 or the hip joint portion 20 is initially set.

  Further, in each of the above embodiments, the coordinates in the height direction and the posture in the roll direction are provisionally set in the waist trajectory, but other coordinates and postures may be provisionally set. Further, instead of the waist trajectory, or together with the waist trajectory, partial coordinates and postures of the ankle trajectory may be temporarily set, and each joint angle may be obtained by the same algorithm as in each embodiment.

  Moreover, although the algorithm in each said Example is applied to creation of the walking pattern of a robot, it applies to creation of the movement pattern in which a robot performs bending motion, jumping, etc. in the same position by changing some elements. It is also possible.

  In addition, the configuration of each part of the apparatus in the present invention is not limited to the illustrated configuration example, and various modifications are possible as long as substantially the same operation is achieved.

The conceptual diagram of a robot system. The flowchart which shows the preparation procedure of the walking pattern which concerns on 1st Example. The flowchart which shows the correction procedure of a walking pattern. The flowchart which shows the preparation procedure of the walking pattern which concerns on 2nd Example. The graph which shows the relationship between elapsed time and a knee joint angle. The schematic diagram for demonstrating the meaning of the parameter in numerical formula.

Explanation of symbols

11 Biped robot (legged robot)
12 Computer (Exercise pattern creation device)
14 Legs 15 Toes 16 Lumbars 17 Control Device 20 Hip Joint 23 Knee Joint

Claims (7)

A plurality of leg portions composed of a plurality of joint portions, a foot tip portion continuous to the lower end side of the leg portion, a waist portion continuous to the upper end side of the leg portion, and an operation of each joint portion based on a predetermined motion pattern In a program for creating the movement pattern by a computer for a legged robot provided with a control device for controlling
In a state in which a part of the joint angle in at least some of the legs is arbitrarily set in advance, and a foot trajectory that is the trajectory of the foot tip and a waist trajectory that is the trajectory of the waist are provisionally set, Based on a predetermined restraint condition, a change is made to at least a part of the toe trajectory and / or the waist trajectory, and by calculating an inverse kinematic solution related to any of the toe trajectory and / or the waist trajectory in advance, A robot motion pattern creation program characterized by obtaining joint angles excluding a set joint angle. A plurality of leg parts including a hip joint part and a knee joint part, a toe part connected to the lower end side of each leg part, a waist part connected to the upper end side of the leg part, and each joint part based on a predetermined motion pattern In a program for creating the motion pattern with a predetermined computer for a legged robot provided with a control device for controlling the operation of
In the state where various conditions including a foot tip trajectory that is the foot tip trajectory, a 5-degree-of-freedom waist trajectory that is the trajectory of the waist excluding coordinates in the height direction, and knee joint angles on the stance side are initially set,
Determining whether each leg is a standing leg or a free leg for a predetermined time;
By calculating an inverse kinematic solution from the foot tip trajectory, the 5-degree-of-freedom hip trajectory, and the knee joint angle for each leg determined to be a stance leg, each of the leg side excluding the knee joint angle is calculated. A step of determining the stance side to obtain the joint angle and the height of the hip joint,
For the leg determined to be a free leg, an inverse kinematic solution is obtained from the position and posture of the hip joint on the stance side determined in the stance side determination step, the foot tip trajectory and the 5-degree-of-freedom waist trajectory. By calculating, the free leg side determining step for obtaining each joint angle on the free leg side,
A program for creating a movement pattern of a robot, which is executed by the computer. In a state where the limit range of the physical quantity related to the movement of the knee joint is further initialized,
In the step of determining the stance side, the transition from the free leg to the stance leg is performed when the physical quantity is out of the limit area when the limb is displaced to a preset knee joint angle on the stance side. After correcting to the knee joint angle, by calculating an inverse kinematic solution from the corrected knee joint angle, the toe trajectory, and the 5-degree-of-freedom waist trajectory, each joint angle and hip joint on the stance side The robot motion pattern creation program according to claim 2, wherein the height of the robot is determined. In a state where the limit range of the physical quantity related to the movement of the knee joint is further initialized,
In the step of determining the free leg side, when the physical quantity of the knee joint part on the free leg side is outside the restriction area, the knee joint angle on the free leg side is fixed to a predetermined value where the physical quantity is within the restriction area, 4. The program for creating a robot motion pattern according to claim 2, wherein each joint angle on the free leg side is determined by calculating an inverse kinematic solution that also takes into account the motion of the waist. A plurality of legs including knee joints, a foot part connected to the lower end side of each leg part, a waist part connected to the upper end side of the leg part, and an operation of each joint part based on a predetermined walking pattern For a legged robot provided with a control device for controlling, in a program for creating the movement pattern by a predetermined computer,
Various conditions including a foot tip trajectory that is the foot tip trajectory, a four-degree-of-freedom waist trajectory that is a trajectory of the waist except for the posture in the roll direction and the coordinate in the height direction, and various knee joint angles are initially set. In the state
By using the fact that the height of the waist calculated from the foot tip, the 4-degree-of-freedom waist track, and the knee joint angles on the basis of each foot is mutually the same, Calculating the posture and height coordinates by calculation;
Each joint excluding a preset knee joint angle is calculated by calculating an inverse kinematic solution from the foot trajectory, the knee joint angles, and the waist trajectory including the posture in the roll direction and the coordinates in the height direction. The step of determining the angle,
A program for creating a movement pattern of a robot, which is executed by the computer.   An exercise pattern creation apparatus, wherein the exercise pattern creation program according to any one of claims 1 to 5 is stored, and the exercise pattern is created based on the exercise pattern creation program.   6. A robot comprising the motion pattern creating apparatus according to claim 1, wherein the motion pattern creating program is stored, and the motion pattern creating device creates the motion pattern based on the motion pattern creating program. .