JPH0822514B2 - Walking control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a legged moving mechanism, and more particularly to a walking control device suitable for dynamic walking control of a walking mechanism.

[Conventional technology]

A conventional walking control device for a legged mobile device is disclosed in Japanese Patent Laid-Open No. 50996/1975.
No. 2, JP-A-53-36867, JP-A-53-61853, etc., a link mechanism is used to generate an elliptic-like flat curve loop motion similar to the walking motion of an animal. It was configured to give exercise to the tip of the leg to walk.

[Problems to be Solved by the Invention]

In the above-mentioned conventional technique, the timing at the time of landing of the leg in terms of setting the locus of the leg tip and the relative motion between the leg tip and the walking surface are not sufficiently considered, and the timing is missed particularly when applied to dynamic walking. There is a problem that the stability of walking is lost due to the landing of the leg and the occurrence of disturbance at the time of landing due to the relative velocity between the tip of the leg and the front surface, and the generation of the leg trajectory is determined by the geometric configuration of the leg mechanism. Therefore, there is a problem in that an appropriate leg tip trajectory cannot be generated for various walking conditions.

An object of the present invention is to provide a walking control device that realizes dynamic walking of a walking mechanism having four legs in particular.

[Means for solving the problem]

The above-mentioned purpose is to determine the stride, the walking cycle, the allowance, the allowance period, etc., and the trajectory of the legs of the parallel pair or the diagonal pair based on this parameter with the connecting point of the leg and the torso as the origin. First and second locus generation units that
This is achieved by including a joint control unit that positions and controls the leg tips of the pair of legs based on the leg tip trajectories from the trajectory generators.

[Action]

According to the parameter from the parameter setting unit, the first and second locus generation units match the horizontal speed of the tip of the leg from the time point after the allowance period after the leg is separated from the walking surface to the landing, Further, the height of the tip of the leg from the walking surface when the margin time has elapsed is set to a value of the margin height, whereby the joint control unit performs positioning control of the leg tip.
As a result, it is possible to suppress the collision between the tip of the leg and the walking surface at the time of landing the leg, and to minimize the deviation of the landing position of the leg due to the fall of the walking mechanism due to dynamic walking. The vertical movement of the tip of the leg in the leg recovers the change in the posture of the walking mechanism due to the fall.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the configuration of the walking control device of the present invention. In this figure, a walking mechanism 5 to which the walking control device of the present invention is applied is a trunk 6 and four walking mechanisms connected thereto. It consists of legs 7-10. Next, the configuration of the walking control device will be described. The control device includes a parameter generation unit 1, a first trajectory generation unit 2, a second trajectory generation unit 3, and a joint control unit 4. Parameter setting unit 1 is step length S, walking cycle
Parameters of T, margin height h, margin period τ having a value less than half of walking cycle T, initial ground contact position x, and leg height H are determined. The first locus generation unit 2 generates a target locus (X _r , Z _r ) of the leg tip based on the parameter set by the parameter setting unit 1 with the connecting point of the leg 6 and the legs 7 to 10 as the origin. . Second
The locus generation unit 3 of 1 generates a target locus (X _r ′, Z _r ′) whose T / 2 phase is delayed with respect to the target locus (X _r , Z _r ) generated by the first locus generation unit 2. The joint control unit 4 controls the positioning of the leg tips of the legs 7 and 8 located diagonally based on the target locus (X _r , Z _r ) generated by the first locus generation unit 2,
Further, based on the target locus (X _r ′, Z _r ′) generated by the second locus generation unit 3, positioning control of the leg tips of the legs 9 and 10 located at other diagonals is performed.

The first locus generation unit 2 uses the above-mentioned leg tip locus (X _r , Z _r )
Although a function for calculating is set, an example in which the target locus (X _r , Z _r ) is generated by the first locus generator 2 will be described with reference to FIG. Tip 7c of the legs 7 is located at an initial state t = 0 at the walking surface position on _{11 P1 1 (-X, H)} , moved to t = positioned τ point _{P 2 (Z r = H-} h) And at this point the walking surface
The height from 11 to the tip 7c of the leg 7 is set to allowance h, and the horizontal velocity of the leg tip is based on the walking speed V (= -S / T). And the tip 7c of the leg 7 Position to ground at time The horizontal speed of the tip of the leg until it moves to Is maintained. Also From the position P ₃ to the position P ₁ during the period from time t to t = T Move horizontally with. In this way, the leg tip locus is set as a function having the walking cycle T as a cycle. The setting conditions of the function for generating the above trajectory are as follows.

0 <Z _r (t) <H (0 <t <τ) (2) The function set in the second trajectory generation unit 3 is basically the same as the function set in the first trajectory generation unit 2, but has a configuration in which the phase is delayed by T / 2.

Next, a configuration example of the components 4a to 4d of the joint control unit 4 will be described with reference to FIG. Since all the constituent elements 4a to 4d have the same configuration, the constituent element 4a will be described as an example. The component 4a is a conversion unit that calculates the respective target joint angles θ _r1 and θ _r2 of the joints 7a and 7b based on the target locus (X _r , Z _r ) and the following functional expression determined by the geometric condition of the leg 7. 4a ₁ and Joint angle sensors 7d and 7e that detect the joint angles of the joints 7a and 7b,
Deviations Δθ ₁ and Δθ ₂ between the joint angles θ ₁ and θ ₂ detected by these joint angle sensors 7d and 7e and the target joint angles θ _r1 and θ _r2
And subtraction units 4a ₂ and 4a ₄ and drive units 4a ₃ and 4a ₅ that supply drive outputs proportional to the deviations Δθ ₁ and Δθ ₂ to the joint drive actuators 7f and 7g. With the configuration of the joint control unit 4, the joint angles θ ₁ and θ ₂ are controlled to follow the target joint angles θ _r1 and θ _r2, and the position (X, Z) of the tip 7c of the leg 7 is set to the target locus (X _r , It follows Z _r ).

Next, the operation of the above-described embodiment of the walking control device of the present invention will be described.

The first trajectory generation unit 2 and the second trajectory generation unit 3 generate the desired leg tip trajectory under the conditions shown in equations (1) to (6) based on the parameters given from the parameter setting unit 1, respectively. Based on a pair of legs 7,8 and a pair of legs 9,10 T
It realizes walking by performing a movement with a phase shift of / 2. That is, in a certain half-walking cycle, the legs 7 and 8 are in contact with the walking surface 11 to move the trunk 6 forward, and the legs 9 and 10 move their tips in the traveling direction.
In the next half-walking cycle, the legs 9 and 10 are in contact with the ground, and the tips of the legs 7 and 8 are in the traveling direction. The walking mechanism 5 moves forward by the two pairs of legs periodically and alternately moving.

Next, the walking mode of the walking mechanism 5 will be described in detail. In this embodiment, the target motions of the two legs diagonally located are the same, and as the target motion of the walking mechanism 5, only the two legs diagonally located always support the body 6 and move forward. There is. However, the posture of the walking mechanism 5 cannot be kept stable by touching down only two legs, and the walking mechanism 5 has a time constant in the traveling direction or the opposite direction with the line connecting the two ground contact points as the central axis. To fall. FIG. 4 shows the target motion of one leg from the stationary system of the walking surface 11, and the joint 7a
Moves forward at a walking speed V, and at time t = τ, the tip 7c of the leg has moved to a position P ₃ just above the ground contact point P ₃ , Vertically descends toward the grounding point P ₃ until reaching. If the leg movement is determined under such conditions, the walking can be stably continued even if the traveling mechanism 5 falls over during walking. That is, as shown in FIG. 5, the joint 7a draws a locus of descending together with forward movement along with the fall motion as shown by the solid line, but before the tip 7c of the leg touches the walking surface 11, the position P ₂ is reached. If it can move, the tip 7c of the leg can be located immediately above the ground contact point P ₃ with the relative velocity to the walking surface 11 being 0, and the tip 7c of the leg 7 reaches the ground contact point P ₃ due to the fall. After that, the trajectory of the joint 7a approaches toward the target trajectory by the vertical motion of the leg tips 7c, At this point, it perfectly matches the target trajectory. Therefore, with _{respect to the} amount of fall h _f of the joint 7a due to the fall of the walking mechanism 5 and the elapsed time τ _f from t = 0, the margin height h and the margin time τ are set as h> h _f and τ <τ _f . If selected by, the above walking form can be realized.

As described above, according to the configuration of the present embodiment, even in an unstable walking mode due to the ground contacting only two legs on the diagonal,
It is possible to always land the tip of the leg at a predetermined ground contact point,
In addition, it is possible to reduce the horizontal impact force received from the walking surface when landing on the legs, and it is possible to autonomously correct the posture deviation of the walking mechanism due to the fall.

FIG. 6 shows the structure of another embodiment of the present invention. In this embodiment, the elements with the same numbers as in FIG. 1 represent the same elements.

In the present embodiment, the target locus (X _r , Z _r ) generated by the first locus generation unit 2 is given to the legs 7 and 10 arranged on one side surface of the walking mechanism 5 via the components 4a and 4b. , Second again
Target locus (X _r ′, Z _r ′) generated by the locus generation unit 3 of
Is given to the legs 8 and 9 arranged on the other side surface of the walking mechanism 5 via the components 4c and 4d.

In this example, the legs 7 and 10 move in the same manner and the legs 8 and 9 move in the same manner.
8 and 9 give the walking mechanism 5 a forward movement. In this case, the fall of the walking mechanism associated with walking occurs with the line connecting the two ground contact points of the legs 7, 10 or legs 8, 9 as the center of rotation, but it is similar to the operation described in the above-described embodiment of the present invention. In principle, it is possible to stabilize walking.

It is obvious that the walking control system described in one embodiment and another embodiment of the present invention may be configured by hardware or a combination of software and hardware.
Although the joint control unit 4 is configured to control a leg having a two-joint rotary joint system as a control target, the joint multi-joint system having three or more joints, or the direct-acting multi-joint system having two or more joints, or two joints.
A leg having a multi-joint rotation / linear motion joint system may be configured as a control target.

〔The invention's effect〕

As described above, according to the present invention, with respect to the fall motion of the walking mechanism during walking, the impact at the time of landing of the leg is mitigated, the tip of the leg is landed at a predetermined ground contact point, and the walking mechanism accompanying the fall motion is provided. It is possible to generate a leg motion that autonomously corrects the deviation of the posture of the. As a result, it is possible to provide a walking control device that realizes stable dynamic walking of a walking mechanism having four legs.

[Brief description of drawings]

1 and 3 are configuration diagrams of an embodiment of the present invention, and FIG.
FIG. 4, FIG. 4 and FIG. 5 are explanatory diagrams of the operation of one embodiment, and FIG. 6 is a configuration diagram of another embodiment of the present invention. 1 ... Parameter generation unit, 2 ... First trajectory generation unit, 3
...... Second trajectory generation unit, 4 ... Joint control unit, 5 ... Walking mechanism, 7-10 ... Legs.

Front Page Continuation (72) Inventor Kazutoshi Suga, Machinery Research Center, Hiritsu Manufacturing Co., Ltd., 502, Kazunachi-cho, Tsuchiura, Ibaraki Prefecture (72) Inventor Yoshihiro Sakakibara, 502, Jinmachi-machi, Tsuchiura, Ibaraki Prefecture (72) Inventor Makoto Hattori, 502 Kintatemachi, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. (72) Yutaka Nakano 3-1-1, Sachimachi, Hitachi, Ibaraki Prefecture Hitachi Ltd., Hitachi Works Examiner Shinichi Shimada (56) Reference JP-A-63-278773 (JP, A)

Claims (1)

[Claims] 1. A walking control device for controlling a walking motion of a walking machine having a plurality of parallel or diagonal pairs of legs and a trunk connecting the legs to each other. A parameter setting unit for setting a parameter such as a margin period having a value equal to or less than the cycle, and based on the parameters from the parameter setting unit, the loci of the tips of the legs of the one pair are set to the tip of the legs during the half-walking period. To move the torso horizontally, and in the following half-walking cycle, remove the tip of the leg from the ground, and move the tip of the leg to the next landing point before the allowance time elapses after the leg disengages. Then, from the end of the allowance period to the end of the half-walking cycle during leg disengagement, it is generated as a locus for lowering the leg tip toward the landing point while keeping the horizontal relative velocity between the leg tip and the ground at zero. 1 trajectory generator, and A first trajectory based on a parameter from the parameter setting section, the trajectory of the tip of the leg of the other pair is generated as a trajectory whose phase is shifted by a half walking cycle with respect to the trajectory generated by the first trajectory generation section; And a joint control unit for positioning the leg tips of each pair of legs based on the leg tip trajectories from the first trajectory generator and the second trajectory generator. Walking control device.