JP4010267B2 - Walking robot for mitigating landing impact, its control method, and gait data correction program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a mechanical system composed of a left leg link, a waist and a right leg link, and uses a plurality of joints existing in the mechanical system to determine the relative posture of the left leg link, the waist and the right leg link. The present invention relates to a control technology of a robot that walks by changing it.
[0002]
[Prior art]
Robots that walk by changing the relative postures of the left leg link, the waist, and the right leg link have been developed. Normally, the waist and left upper thigh are connected by the left hip joint, the left upper thigh and the left lower thigh are connected by the left knee joint, the left lower thigh and the left toe are connected by the left ankle joint, and the waist and the right upper thigh are connected by the right hip joint. The right upper leg and the right lower leg are connected by the right knee joint, and the right lower leg and the right foot are connected by the right ankle joint. The mechanical system composed of the left leg link, the waist, and the right leg link has multiple joints. By using these joints, the relative posture of the left leg link, the waist, and the right leg link is changed. be able to.
[0003]
When the relative postures of the left leg link, the waist, and the right leg link are changed, the relative postures of the left leg link, the waist, and the right leg link must be changed so that a result of walking is obtained as a result.
For this purpose, gait data that indicates the positions and postures of the left toe, waist, and right toe is used. The gait data stores data indicating the position and posture of the left foottip, waist, and right foottip over time. The robot walks by changing the relative postures of the left leg link, the waist and the right leg link over time in accordance with data indicating the positions and postures of the left foot tip, the waist and the right foot tip which change over time.
[0004]
In the gait data creation stage, gait data is created assuming changes in the relative postures of the left leg link, the waist and the right leg link. From the state where the toes of both the left and right leg links are in contact with the ground, the foot of one leg link is lifted, moved forward, and then lowered to move the free leg link one step further and land Create data.
[0005]
A robot having a left leg link, a waist, and a right leg link is heavy, and it is inevitable that the constituent members bend. When the component member bends, the toe height of the free leg link will be lower than the toe height indicated by the gait data. If the toe height of the free leg link falls, the landing will occur at a timing earlier than the timing when the free leg link is assumed to land on the gait data. In other words, the gait data is landed while the foot of the free leg link is intended to be lowered and landed. If the toes of the free leg link land while the toes of the free leg link are being lowered, the robot will still play against the hips after landing (because the gait data has not yet landed, As a result, the landing leg kicks the floor. If the landing leg kicks the floor, the landing impact will increase and the robot will become unstable. For this reason, there is a problem that the robot cannot walk at high speed. On the outside, it appears as if you stepped on the floor twice when landing, creating a sense of incongruity.
[0006]
Technologies to mitigate landing impact have been proposed. Patent Document 1 discloses a technique for mitigating a landing impact by mounting an impact mitigating member on a sole part. Patent Document 2 employs a vertical link mechanism that raises the free leg link by lowering the standing leg link with respect to the waist, and quietly landing the free leg link by lifting the descending free leg link with respect to the standing leg link. Techniques for making them disclosed are disclosed.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-33941 [Patent Document 2]
Japanese Patent Laid-Open No. 2001-62761
[Problems to be solved by the invention]
A trade-off relationship exists in which the posture of the robot in a standing position becomes unstable if an attempt is made to secure a sufficient impact mitigation capability by attaching an impact mitigation member to the sole, and there is a limit.
The vertical link mechanism that raises the free leg link by lowering the standing leg link with respect to the waist, and the technology that lifts the descending free leg link with respect to the standing leg link needs to add a vertical link mechanism that is not originally required. There is. Further, when a program for lifting the descending free leg link with respect to the standing leg link is required, the program must be created uniquely for each type of robot or each operation of the robot. A low-rigidity and flexible robot requires a program that compensates for it, and a program that compensates for a robot that flexes under the influence of inertia to walk at high speed is required. It is necessary to create a unique program for each type of robot or each operation mode of the robot, and a very troublesome work is required.
[0009]
[Means and Actions for Solving the Problems]
The robot created in the present invention is based on gait data indicating the positions and postures of the left toe, waist and right toe, and a plurality of joints existing in a mechanical system composed of the left leg link, the waist and the right leg link. A joint angle group calculating means for calculating each joint angle, and an actuator for adjusting the joint angle of each joint to the joint angle calculated by the joint angle group calculating means, and the left leg link according to the instructed gait data And a robot that walks by changing the relative posture of the waist and right leg links. The robot created by the present invention is provided with means for correcting the gait data indicating the height of the grounded toes to the side away from the waist height in order to reduce the landing impact. .
[0010]
When the gait data indicating the height of the grounded toes is corrected to the side away from the waist height, the waist position is moved away from the toes of the grounded legs. As a result, the waist position is moved away from the floor on which the ground leg is grounded. That is, when the floor is used as a reference, the position of the waist is lifted upward.
When the waist position is lifted upward, the toe height of the free leg link is also raised, and the phenomenon that the toe height of the free leg link falls below the height indicated by the gait data due to the bending that occurs in the mechanical system is compensated. The toe height of the actual free leg link matches the height indicated by the gait data. For this reason, it does not land at a timing earlier than the timing at which the free leg link is assumed to land on the gait data. Since the landing leg link is not intended to land while lowering the tip of the free leg link, the landing leg link does not kick the floor, and the floor is The movement that seems to step on does not appear.
[0011]
When moving the height of the toes of the grounding leg away from the height of the waist, the distance is increased over time from the time when the toes landed, and then until the time when the other toes landed. It is preferable to adjust to a predetermined distance.
The walking posture of the robot is stabilized by increasing the distance gradually and gradually moving away from the height of the waist at the moment when the leg reaches the grounded leg after landing. If you move away gradually, but you move too slowly, the other foot will land before compensating for the effects of deflection. At the latest, it is necessary to adjust the distance to the extent that the influence of the deflection can be compensated until the time when the other foot tip lands next. It is only necessary that the distance is adjusted to a predetermined distance until the time when the other foot landing is next, and it is possible to adjust the distance to a predetermined distance before that time, or just at that time, the predetermined distance is reached. It can also be adjusted. If the other foot is adjusted to a predetermined distance before the next landing, it is possible to respond regardless of the walking speed.
[0012]
After the time when the tip of the grounding leg is away from the height of the waist and the other foot has landed, the distance away from the waist is decreased over time, and then the time when the tip of the foot floats It is preferable to return to zero before.
If the tip of the grounded leg that is standing on one leg is away from the height of the waist, the other tip will land at the intended timing and transition to the grounded state on both legs. . After transitioning to the ground contact state of both legs, the height of the foot of the newly landed leg is kept away from the height of the waist while the height of the foot of the leg that was originally grounded is the height indicated by the gait data It is preferable to return to. The leg that was originally in contact with the ground is the leg that floats off the floor and becomes a free leg, and the correction amount is reset to zero until the point where the leg tip floats, indicating the gait data. If it is returned to the height, the toes of the leg float at the timing assumed by the gait data. When this technique is used, both the landing timing and the floating timing are maintained at the timing assumed by the gait data.
[0013]
The present invention can also be said to have created a new control method for a walking robot. In this control method, gait data indicating the position and posture of the left toe, waist, and right toe is converted into the following steps:
(1) a step of determining whether the left one leg standing state, the both leg standing state, the right one leg standing state from the height of the left toe and the right toe;
(2) correcting the gait data indicating the height of the left foot tip to the side away from the height of the hips until reaching the stance state of both legs through the left one leg stance state;
(3) The gait data instructing the height of the right foot tip is corrected by a process of correcting the gait data to the side away from the waist height during the period from the right one leg standing state to the both leg standing state.
Then, the robot is caused to walk by instructing the robot with corrected gait data.
“During the period from the one-leg stand state to the both-leg stand state” means “including before and after the start time of the both leg stand state”. What is important is that only the necessary amount is corrected at the start time of the both-leg stand state, and in order not to change the correction amount suddenly, it is necessary to correct including both before and after the start time of the both-leg stand state. . As long as the condition is satisfied, there are no particular restrictions on the start time and end time of correction. However, it is preferable that the correction is completed and the correction amount is returned to zero until the timing when the foot of the leg is scheduled to float next time, but this is also absolutely necessary. It is not done. This is because no serious problem occurs even if the gait data deviates from the expected floating timing.
[0014]
To implement the above control method, a program for correcting gait data is required. The program created in the present invention is processed by the computer as follows:
(1) A process for determining whether the left leg standing state, the both leg standing state, or the right one leg standing state from the height of the left toe and right toe,
(2) processing for correcting the gait data indicating the height of the left foot tip to the side away from the height of the waist during the period from the left one leg standing to the both leg standing;
(3) The gait data that indicates the height of the right foot tip is corrected to the side away from the waist height during the period from the right leg standing state to the both leg standing state.
When this program is executed, the gait data for operating the robot so that it does not land at a timing earlier than the timing at which the toe of the free leg link is supposed to land on the gait data before correction. It is corrected. Since the landing leg is not intended to land while lowering the tip of the free leg link, the landing leg does not kick the floor and the floor is landed twice when landing. The motion that seems to step on does not appear.
[0015]
[Embodiment]
The main features of the embodiments described below are listed first.
(Mode 1) When the toes of the free leg link land and shift to the both-legs ground state, a correction is started to reduce the height of the newly landed toes. It starts to decrease the correction amount of the toes that are corrected by a predetermined distance. The correction amount of the leg that has started to decrease the correction amount by increasing the correction amount of the leg that started correction to a predetermined distance until the time when the leg that originally grounded floated next and the ground contact state of both legs ended Is reduced to zero.
[0016]
【Example】
FIG. 1 shows a mechanical configuration of a biped walking robot 84 having a mechanical system composed of a left leg link 47, a waist 1 and a right leg link 17.
The left leg link 47 includes a left upper leg 48, a left knee joint 50, a left lower leg 52, a left ankle joint 58, and a left foot tip 62. The left knee joint 50 has a variable joint angle around the pitch axis y, and the left ankle joint 58 has a variable joint angle around the pitch axis y and a joint angle around the roll axis x. In FIG. 1, a joint is represented by an actuator that changes the joint angle for the sake of clarity of illustration. For example, reference numeral 50 is commonly used for actuators that change the joint angles of the knee joint. Reference numeral 54 is an actuator that changes the joint angle around the pitch axis y of the ankle joint 58, and reference numeral 56 is an actuator that changes the joint angle around the roll axis x. The left toe 62 has a force acting between the left toe 62 and the floor, in this case, a force in the roll axis x direction, a force in the pitch axis y direction, a force in the gravity line z direction, and the roll axis x. , A six-axis force sensor 60 for measuring a moment about the pitch axis y and a moment about the gravity line z is attached.
The left and right leg links 17 and 47 are symmetrical, and the right leg link 17 includes an upper right thigh 18, a right knee joint 20, a right lower thigh 22, a right ankle joint 28, and a right foot tip 32. The right knee joint 20 has a variable joint angle around the pitch axis y, and the right ankle joint 28 has a variable joint angle around the pitch axis y and a joint angle around the roll axis x. A six-axis force sensor 30 is also attached to the right foot tip 32.
The waist 1 includes a waist plate 8 and a waist pillar 4, and a waist joint 6 is provided between them. A gyro 2 for measuring the inclination angle of the waist pillar 4 around the pitch axis y, the inclination angle around the roll axis x, and the rotation angle around the gravity line z-axis is fixed to the waist pillar 4. The tilt angle around the pitch axis y and the tilt angle around the roll axis x of the lumbar column 4 are not affected even when the hip joint 6 rotates.
[0017]
The left leg link 47 and the waist 1 are connected by a left hip joint 46. The left hip joint 46 includes an actuator 40 that changes the joint angle around the gravity line z-axis, an actuator 42 that changes the joint angle around the pitch axis y, and an actuator 44 that changes the joint angle around the roll axis x. . The right leg link 17 and the waist 1 are connected by a right hip joint 16. The right hip joint 16 includes an actuator 10 that changes the joint angle around the gravity line z-axis, an actuator 12 that changes the joint angle around the pitch axis y, and an actuator 14 that changes the joint angle around the roll axis x. .
[0018]
When walking using the mechanical system of FIG. 1, the relative postures of the left leg link 47, the waist 1, and the right leg link 17 must be changed so that the result of walking is obtained as a result.
For this purpose, gait data that indicates the positions and postures of the left toe, waist, and right toe is used. As shown in FIG. 2, the gait data indicates the positions and postures of the left foottip, the waist, and the right foottip in a global coordinate system that defines the coordinates of the space in which the robot is active. In order to indicate the positions of the left toe, waist and right toe, a reference point L0 is set for the left toe 62, a reference point R0 is set for the right toe 32, and a reference point W0 is set for the waist 1. Is stipulated. In order to indicate the posture of the left toe, waist and right toe, a vector L perpendicular to the left toe 62 is assumed, and a vector R perpendicular to the right toe 32 is assumed and extends along the waist column 4. A vector W is assumed. As shown in FIG. 2, the gait data includes the x, y, z coordinates of the reference point L0 of the left toe 62, the x, y, z coordinates of the reference point R0 of the right toe 32, and the waist 1 in the global coordinate system. The x, y and z coordinates of the reference point W0 are indicated. Further, the pitch angle Lα, roll angle Lβ, and yaw angle Lγ of the vector L perpendicular to the left foot tip 62 are designated, and the pitch angle Rα, roll angle Rβ, and yaw angle Rγ of the vector R perpendicular to the right foot tip 32 are designated. And the pitch angle Wα, roll angle Wβ, and yaw angle Wγ of the vector W extending along the waist column 4 are instructed. As shown in FIG. 3, the gait data stores data indicating the positions and postures of the left foottip, the waist, and the right foottip over time. The robot 84 changes the relative postures of the left leg link 47, the waist 1 and the right leg link 17 with time according to gait data indicating the positions and postures of the left foot tip, the waist and the right foot tip which change over time. Walk.
[0019]
As shown in FIG. 4, the robot inputs gait data that indicates the positions and postures of the left toe, waist, and right toe, and the joint angle around the z-axis and the joint angle around the y-axis of the left hip joint 46 The joint angle around the x axis, the joint angle around the y axis of the left knee joint 50, the joint angle around the y axis of the left ankle joint 58, the joint angle around the x axis, and the joint around the z axis of the right hip joint 16 Calculate the joint angle around the y-axis, the joint angle around the x-axis, the joint angle around the y-axis of the right knee joint 20, the joint angle around the y-axis and the joint angle around the x-axis of the right ankle joint 28 In addition, a joint angle group calculation device 70 for calculating the rotation angles of the actuators 40, 42, 44, 50, 54, 56, 10, 12, 14, 20, 24, 26 that change the respective joint angles is provided. The joint angle group calculation device 70 calculates the joint angle group by solving the inverse kinematics. The joint angle group calculation device 70 calculates the joint angle group in real time with the walking motion of the robot. The joint angle group calculation device 70 may be physically outside the robot, or may be a device that transmits and indicates the calculated joint angle group to the robot wirelessly or by wire.
Gait data may be created in advance offline and taught to the robot. Alternatively, gait data can be created in real time while operating the robot. Gait data can also be created by operating the joystick or the like while observing the robot's motion to designate the next motion of the robot. In this case, the gait data created in real time is transmitted to the robot wirelessly or by wire, and the joint angle group calculation device 70 mounted in the robot calculates the joint angle group in real time. Alternatively, the joint angle group calculated by the joint angle group calculating device 70 placed outside the robot may be transmitted to the robot in real time wirelessly or by wire.
[0020]
If the robot is not bent, the robot should walk with the posture changed as instructed by the gait data by adjusting the joint actuator to the calculated rotation angle.
In reality, however, the robot bends. When the robot bends, the actual height of the toe of the free leg becomes lower than the height indicated by the gait data. If the tip of the free leg falls, it will land at a timing earlier than the timing when the free leg is supposed to land on the gait data. That is, in the gait data, the landing is made while the toes of the free leg are intended to be lowered and landed. If the toes of the free leg land during the action of lowering the toes of the free leg, the robot will continue to descend the toes of the free leg against the waist even after landing. The tip of the leg kicks the floor. If the landing leg kicks the floor, the impact at the time of landing will increase and the robot will become unstable. Therefore, the problem that it cannot walk at high speed will arise. In addition, it looks like you step on the floor twice when landing, which gives you a sense of discomfort.
[0021]
According to the research of the present inventor, it has been found that most of the bending that occurs in a walking robot occurs on a standing leg. It was confirmed that the height of the waist (the height of the waist reference point W0 in FIG. 2) falls below the height indicated by the gait data because the stance leg is bent. That is, the difference between the height of the foot of the stance link (the position of the left foot toe reference point L0 because it is the left one leg stand in FIG. 2) and the height of the waist (the position of the waist reference point W0) is the gait data. I confirmed that it was closer than what I indicated. Since the stance leg is bent and the waist position is lowered, the toe height of the free leg falls below the height indicated by the gait data. If the waist position does not fall, the toe of the free leg The landing timing is not off.
[0022]
Therefore, in this embodiment, the gait data is corrected in consideration of the amount of depression of the waist position caused by the deflection of the stance link. If the gait data that indicates the height of the toes that are in contact with the ground is corrected to the side away from the waist height by the amount corresponding to the amount of depression of the waist position caused by the deflection, it is assumed that there is no deflection The height of the instructed waist position should match the height of the waist position that has been sunk by bending. By correcting the gait data by the amount of deflection, the actual height of the waist position matches the height indicated by the gait data. As a result, the actual toe height of the free leg link coincides with the height indicated by the gait data, and the landing timing does not shift.
[0023]
(1) of FIG. 5 shows the change over time of the height of the left foot tip of the gait data before correction, and (2) shows the change over time of the height of the right foot tip of the gait data before correction. . It is instructed to maintain a certain height between landing and next floating. This corresponds to the fact that the height of the feet touching the floor should not change.
If the robot is not bent, the robot should walk with the posture changed as instructed by the gait data by adjusting the joint actuator to the calculated rotation angle. However, since the robot actually bends, the actual height of the toes deviates from that indicated by the gait data in FIGS. Specifically, the actual toe height of the free leg moves downward, and the toes are not lifted as much as the gait data indicates. This shifts the landing timing and increases the landing impact.
In order to cope with this, gait data correction means 80 is incorporated as shown in FIG. The correction means 80 may be incorporated in the mechanical system 84 of the robot, or may be physically provided at another position.
[0024]
FIG. 7 shows a processing procedure by the correcting means 80. The correction process is sequentially executed on the gait data at all times t1, t2, t3... For which the gait data shown in FIG.
In step S2, the state of the gait data to be corrected is determined from the gait data before correction exemplified in FIGS. 5 (1) and (2). The robot is in the state of (1) left-legged stand, (2) both-legged stand, (3) right-legged stand, and (4) the left-legged stand of (1) Return. Here, the left single leg standing state indicates a state where only the left leg is grounded (therefore, the right leg is a free leg), and the right one leg standing state is a state where only the right leg is grounded ( Therefore, the left leg is a free leg). From the heights of the toes of the left and right leg links exemplified in FIGS. 5 (1) and (2), it is determined whether the correction target gait data is in any one of the above (1) to (4). be able to. For each of the times t1, t2, t3,... In FIG. 3, it can be determined which of the states (1) to (4).
[0025]
For convenience of explanation, description will be made from the moment when the right leg lands from the left one leg standing state and transitions to the both leg standing state, that is, the moment when the right leg that was a free leg has landed. At this time, timing is started and the processing in step S4b is enabled. In step S4b, an elapsed time T1 from the moment when the right leg lands and shifts to the both-leg stand state is measured. In a state where the right leg has landed and shifted to the both-leg stand state, in step S6b, the left foot correction amount is reduced to zero along with the elapsed time T1. The downward correction amount in FIG. 7 indicates the correction amount on the side where the toes are moved away from the waist position. In the state where the right leg has landed and transitioned to the standing state of both legs, the left foot correction amount is reduced at a speed at which the left foot correction amount returns to zero before the left leg floats and shifts to the right single leg standing state. To zero. On the other hand, for the right leg that has landed, in step S8b, the correction amount on the side away from the foot position is increased with the elapsed time T1, and when the maximum amount ΔMAX is reached, the correction amount is maintained at the maximum amount ΔMAX. In the state where the right leg has landed and transitioned to the both-legged stand state, the right foot correction amount is adjusted at a speed at which the right foot correction amount reaches the maximum amount ΔMAX before the left leg floats and shifts to the right one-leg stand state. Increase to maintain maximum amount ΔMAX.
[0026]
During the right leg standing state, the left foot correction amount is reset to zero prior to that, so it is maintained at zero (step S6c), and the right leg correction amount that is grounded is adjusted to the maximum amount ΔMAX. The maximum amount ΔMAX is maintained (step S8c).
[0027]
While the right leg is in contact with the ground, the timing is started at the moment when the left leg, which was a free leg, has landed, and the process of step S4d is enabled. In step S4d, an elapsed time T2 from the moment when the left leg lands and shifts to the both-leg stand state is measured. In a state where the left leg has landed and shifted to the both-leg stand state, in step S8d, the right foot correction amount is reduced to zero along with the elapsed time T2. In the state where the left leg has landed and shifted to the standing state of both legs, the right foot correction amount is reduced at a speed at which the right foot correction amount returns to zero before the right leg floats and shifts to the left one leg standing state. To zero. On the other hand, for the left leg that has landed, in step S6d, the correction amount on the side away from the foot position is increased with the elapsed time T2, and when the maximum amount ΔMAX is reached, the correction amount is maintained at the maximum amount ΔMAX. In the state where the left leg has landed and transitioned to the standing state of both legs, the left foot correction amount is adjusted at the speed at which the left foot correction amount reaches the maximum amount ΔMAX before the right leg floats and shifts to the left one leg standing state. Increase to maintain maximum amount ΔMAX.
[0028]
Since the right foot correction amount is reset to zero prior to the left leg standing state, it is maintained at zero (step S8a), and the grounded left leg correction amount is adjusted to the maximum amount ΔMAX. The maximum amount ΔMAX is maintained (step S6a).
[0029]
(3) of FIG. 5 shows the change over time of the height of the left foot toe corrected to compensate for the deflection, and (4) shows the change over time of the height of the right foot of the gait data after correction. Show.
In FIG. 5, when the left leg lands, the left foot correction amount is increased after that time, and then the left foot correction amount is increased at a speed that reaches the maximum amount ΔMAX when the right leg floats and shifts to the left one leg standing state. is doing. Thereafter, the left foot correction amount is maintained at the maximum amount ΔMAX during the left one leg standing leg, and the right leg lands while maintaining the maximum amount ΔMAX. The landing timing of the right leg does not change even if the standing leg is bent. The maximum correction amount ΔMAX is set to a size that compensates for the approach of the height of the toes of the stance and the height of the waist due to bending of the stance. When the right leg lands, the correction amount of the left foot to be the next free leg is reduced. In FIG. 5, the correction amount is returned to zero when the left foot tip becomes the free leg. The moment when the left foot tip floats off the floor and becomes a free leg does not shift.
The same applies to the right leg.When the right leg lands, the right foot correction amount is increased after that time, and then the right leg is moved at a speed that reaches the maximum amount ΔMAX when the left leg floats and shifts to the right single leg standing state. The correction amount is increased. Thereafter, the right leg correction amount is maintained at the maximum amount ΔMAX during the right leg standing leg, and the left leg lands while maintaining the maximum amount ΔMAX. The landing timing of the left leg does not deviate even if the standing leg is bent. The maximum correction amount ΔMAX is set to a size that compensates for the approach of the height of the toes of the stance and the height of the waist due to bending of the stance. When the left leg lands, the correction amount of the right foot tip that will be the next free leg is reduced, and in FIG. 5, the correction amount is returned to zero when the right foot tip becomes the free leg. The moment when the right toe floats off the floor and becomes a free leg does not shift.
[0030]
When the correction amount is increased, the correction amount may be increased after the landing of the leg, and may be increased to a necessary correction amount (sometimes referred to as a predetermined correction amount) before the opposite leg is landed. (5) As in (6), the correction amount may be increased slowly during a single leg stand. It is sufficient that the correction amount is increased to the necessary correction amount at the moment when the opposite leg lands as shown in (6). As shown in (7), it may be increased after the one-leg standing state, or as shown in (8), it may be increased to a necessary correction amount before the one-leg standing state. In order to decrease the correction amount, it is sufficient that the leg is returned to zero before becoming a free leg, and may be decreased after waiting for both legs to stand as shown in (7). As shown in 8), it may be returned to zero before becoming a free leg.
[0031]
As understood from the above, in this embodiment,
(1) a step of determining whether the left one leg standing state, the both leg standing state, the right one leg standing state from the height of the left toe and the right toe;
(2) The gait data that indicates the height of the left foot tip is corrected to the required correction amount at the moment the right foot lands, so that the hip Correcting to the side away from the height of
(3) The gait data that indicates the height of the right foot tip is corrected to the required correction amount at the moment the left foot tip lands, until it reaches the both leg stand state through the right one leg stand state, It is corrected by a process of correcting to the side away from the waist height.
[0032]
FIG. 6 shows the relationship between the gait data correcting means 80 and the peripheral means. The gait data correcting means 80 inputs gait data before correction and outputs gait data after correction. The gait data before correction may be created offline beforehand and taught to the robot. Alternatively, gait data before correction can be created in real time while operating the robot. It is also possible to create gait data before correction by operating the joystick or the like while observing the movement of the robot and specifying the next movement of the robot. In this case, the gait data before correction created in real time is transmitted to the robot wirelessly or by wire, and the joint angle group calculation means 70 mounted in the robot calculates the joint angle group in real time. Alternatively, the joint angle group calculated by the joint angle group calculating means 70 placed outside the robot may be transmitted to the robot wirelessly or in a wired manner in real time.
[0033]
The gait data corrected by the correcting means 80 is input as a command value to the control means 82 of the robot. The robot measuring device 88 mounted on the robot 84 grasps a value indicating the current state of the robot 84 and inputs it to the robot control means 82. The robot control means 82 compares the command value with the current value, performs necessary corrections, calculates the command value used for control, and instructs the joint angle group calculation means 70. The joint angle group calculating means 70 controls the joint actuator 86 by calculating the rotation angle or angular velocity of each actuator. The robot control means 82 uses a so-called inverted pendulum model or a similar control model to prevent the robot from toppling and absorb the influence of unexpected floor irregularities.
[0034]
FIG. 8 shows the force in the Z-axis direction detected by the six-axis force sensors 30 and 60. (1) and (2) show the force in the Z-axis direction when gait data is not corrected, and (3) and (4) show the force in the Z-axis direction when gait data is corrected. Yes. (1) and (3) show the force of the left leg in the Z-axis direction, and (2) and (4) show the force of the right leg in the Z-axis direction.
Obviously, by correcting the gait data, the force in the Z-axis direction is stabilized and the maximum value is decreased. In addition, the toe stepped twice before the correction, but when corrected, the double step phenomenon is resolved. By correcting the gait data, the landing impact is alleviated and it is confirmed that the robot is walking smoothly.
[0035]
Although specific examples of the present invention have been described in detail above, these are examples and do not limit the scope of the claims. Further, the present invention solves several objects, and is not meaningful only when all objects are solved simultaneously, but only by solving one or two objects.
[0036]
【The invention's effect】
According to the present invention, the phenomenon that the landing leg kicks the floor in order to land earlier than the mechanical system is expected to bend can be suppressed, and the landing impact can be mitigated. The phenomenon that the landing leg steps on the floor twice is also eliminated. The robot can walk at a high speed with a natural walking posture.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram showing a mechanical configuration of a walking robot.
FIG. 2 is a diagram showing reference points and reference vectors used by gait data.
FIG. 3 is a diagram schematically showing the content of gait data.
FIG. 4 is a diagram showing calculation means for calculating a joint angle group from gait data.
FIG. 5 is a diagram showing a temporal change in the foot height of the gait data before correction and a temporal change in the foot height of the gait data after correction.
FIG. 6 is a block diagram of a robot control system.
FIG. 7 is a view showing a procedure for correcting gait data.
FIG. 8 is a diagram showing a comparison of the force received by the toes from the floor based on gait data before correction and the case based on gait data after correction.
[Explanation of symbols]
2: Gyro 4: Lumbar column 6: Lumbar joint 8: Lumbar plate 16, 46: Hip joint 20, 50: Knee joint 28, 58: Ankle joint 30, 60: 6-axis force sensor ΔZL: Left foot toe correction amount ΔZR: Right foot toe Correction amount ΔMAX: Necessary correction amount

Claims (5)

Joint angle group that calculates each joint angle of multiple joints existing in the mechanical system composed of left leg link, waist and right leg link from gait data indicating the position and posture of left foot, waist and right foot A calculation means;
An actuator for adjusting the joint angle of each joint to the joint angle calculated by the joint angle group calculating means,
To a robot that walks by changing the relative posture of the left leg link, waist and right leg link according to the gait data instructed,
Means for determining whether the left one leg standing state, the both leg standing state, and the right one leg standing state from the height of the left and right toes of the gait data before correction;
Gait data that indicates the height of the left foot tip, the left foot toe gait data correcting means for correcting the gait data to the side away from the waist height during the period from the left leg standing state to the both leg standing state;
Gait with right foot gait data correction means that corrects the gait data indicating the height of the right foot to the side away from the waist height until it reaches the state of both legs standing from the right leg standing state. robot. Left foot destination gait data correction means, a correction amount for correcting the side away from the height of the waist, over time increases from the time the left foot has landed, then right toes until the point of landing The right foot gait data correcting means adjusts to a predetermined correction amount, and the correction amount to be corrected away from the waist height is increased with time from the time when the right foot landed, and then the left foot landed. The walking robot according to claim 1, wherein the walking robot is adjusted to a predetermined correction amount until a point in time . Left foot destination gait data correction means, a correction amount for correcting the side away from the height of the waist, over time reduces from the time the right foot has landed, then left toes until the time of floating it returns to zero, the right toe gait data correction means, a correction amount for correcting the side away from the waist height, from the time the left foot destination lands to the point where over time reduces, then right toe to float claim 1 or 2 of the walking robot, characterized in revert to zero during. Gait data indicating the position and posture of the left toe, waist, and right toe are processed in the following steps:
From the height of the left toe and right toe, determining the left one leg standing state, both leg standing state, right one leg standing state,
Correcting the gait data indicating the height of the left foot tip to the side away from the height of the waist during the period from the left one leg standing state to the both leg standing state;
The gait data that indicates the height of the right foot tip is corrected by a process of correcting to the side away from the height of the waist until it reaches the stance state of both legs through the right leg standing state,
A robot control method for walking a robot by instructing the robot with corrected gait data. It is a program for correcting the gait data indicating the position and posture of the left toe, waist and right toe through the following processing, and the computer performs the following processing:
A process of determining whether the left leg stand state, the both leg stand state, the right one leg stand state from the height of the left foot tip and the right foot tip,
Correcting the gait data indicating the height of the left foot tip to the side away from the height of the hips until reaching the stance state of both legs through the left leg standing state,
Correcting the gait data that indicates the height of the right foot tip to the side away from the height of the hips until reaching the stance state of both legs through the right leg standing state,
Gait data correction program to execute.

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