JPS6154417B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a posture control device for a power orthosis, and more specifically, it allows a physically disabled person with paralyzed lower limbs to maintain a standing position and to walk by applying power from the outside. The present invention relates to a posture control device for a power orthosis that makes it possible to control the posture of a power orthosis.

Conventionally, this type of orthosis has been used to maintain the upper body and lower limbs of paralyzed patients in a straight line, allowing the disabled person to walk on his own by relying on a cane or support. In addition, conventionally known power orthoses include the one made by M. Vukobratovic of Belgrade University, but this is intended for rehabilitation purposes, and is used to enable patients to walk on two legs by applying power to them. It's not for. Therefore, there is no bipedal locomotion control device for power orthoses that is close to the present invention, but there have been various studies on bipedal locomotion control for robots, so one example will be explained.

FIG. 1 is a simplified human link model used as a plant for a bipedal locomotion control system.
In the figure, 1 is the upper body, 2a and 2b are the thighs, and 3
a and 3b indicate the lower legs, and 4a and 4b indicate the ankles. In addition, θ ₁ , θ ₂ , θ ₃ , θ ₄ and θ ₅ indicate the angle of each link from the vertical plane, and T ₁ , T ₂ , T ₃ ,
T ₄ , T ₅ and T ₆ represent the torques acting on the contacts of each link.

Previously reported research on bipedal locomotion control systems includes H. Hemami at Ohio University, and in Japan, the Kato laboratory at Waseda University, the Arimoto laboratory at Osaka University, and the Mita laboratory at Chiba University. Common to these studies is the attempt to realize bipedal walking by controlling the angle of each joint of the human link model according to command signals, but in order to do so, it is necessary to Therefore, all conventional bipedal walking systems use the angle of the ground leg as a reference angle with respect to the vertical plane.
That is, in FIG. 1, if the foot touches the ground parallel to the floor, the angle _θ1 of the grounding leg can be determined from the angle meter attached to the foot. Originally, the angle meter measures the relative angle difference between each joint, so from θ ₁ and the relative angle difference measured from the angle meter installed at each joint, θ is sequentially calculated.
₂ , θ ₃ , θ ₄ , and θ ₅ can be obtained, and using these, a control system as shown in FIG. 2 can be constructed. In Figure 2, θ _R1 , θ _R2 , θ _R3 , θ
_R4 and θ _R5 are angle signals of each link given as commands, and Δθ ₁ , Δθ ₂ , Δθ ₃ , Δθ ₄ and Δθ ₅ are deviation signals. These signals are input to block 5, which comprises an arithmetic processing circuit and an actuator, which applies appropriate arithmetic processing to the signals and then applies them to the actuator to generate torque. Further, T ₁ to _{T 5} are driving torques for each joint obtained as the output of the actuator, and are applied to the block 6 consisting of the plant and the angle meter. This drives the human link model, which is a plant. As mentioned above, what is detected as the output of the plant is θ ₁ and the angle difference between each joint θ ₂ −θ ₁ , θ ₃
−θ ₂ , ..., so by processing these, θ
The bipedal walking control is performed by determining the respective values of ₁ and _.theta.5 and feeding them back.

As described above, conventional devices are configured to obtain angle reference information from the grounding legs, so (a) when the floor is uneven and the soles of the feet do not touch the ground in parallel, or when the ground is on a slope, etc. There were drawbacks such as the inability to obtain correct angle reference information, and (b) the need to switch the control system between the left leg and right leg contact.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and uses a gyro to always obtain the correct angle reference from the vertical plane and perform complex processing such as switching the control system. First, it is an object of the present invention to provide a posture control device for a power equipment that can perform accurate control even on uneven roads and slopes.

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 3a and 3b, a hydraulic actuator 7 is attached to each joint, to which a control circuit and a hydraulic motor section 8 are connected. 9 is a hydraulic tank. The control system is constructed as shown in FIG. 4, and is not much different from the conventional one shown in FIG. 2, except for the conventional plant plus the block 6a in which a gyroscope for the angle meter 6 is added. When the gyroscope is mounted on the upper body, it is possible to detect the angle θ ₃ of the upper body in Fig. 1 as described later, so by using this as an angle reference with respect to the vertical plane and assembling the control system shown in Fig. 4, θ can be detected. ₁ , to _θ5 , and the same control as the conventional one can be performed.

A mechanism shown in FIG. 5 can be considered as a gyroscope that easily detects the angle from the vertical plane. In the figure, a rotating shaft 11 that supports the rotor 10 of the gyro
is supported by an inner support frame 12, and this inner support frame 12 has a support shaft 1 attached to an outer support frame 13 fixed to the upper body.
It is supported through 4. A weak spring 15 is stretched between the inner support frame 12 and the outer support frame 13.

With the above configuration, during walking movement, the angle of the upper body changes periodically as the user walks, but if this is averaged over time, it is considered to be approximately vertical. On the other hand, due to the rigidity of the rotor 10, the gyro does not follow short-period movements and maintains a constant attitude relative to the inertial space (and therefore relative to the vertical plane). Therefore, by connecting the gyroscope and the outer support frame 13 fixed to the upper body with a weak spring 15 (a damper may be attached in some cases) to give a weak restoring moment to the gyroscope, the gyroscope's The attitude angle is approximately the average attitude angle of the outer support frame 13, that is, the vertical state is maintained, and this can be used as a vertical reference. Therefore, the temporary posture angle θ ₃ of the upper body can be determined by detecting the rotation angle of the support shaft 14 or by measuring the spring force of the spring 15. Updating the gyroscope angle (necessary, for example, when waking up from a sleeping position) can be done by remaining upright for a certain period of time.

The above description has been made regarding the case where the present invention is used to control a power orthosis, but the present invention can also be applied to general bipedal walking systems such as robots.

As described above, according to the present invention, the angle from the vertical plane of the torso is detected using a gyroscope instead of using the angle information from the contact surface of the grounding leg as the angle reference. Along with the switching,
This has the advantage of being able to perform correct control even on uneven roads, slopes, etc., without having to perform complicated processing such as switching control systems.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of the structure of a simplified human link model of a power orthosis to which this invention is applied, Fig. 2 is a control block diagram of a conventional device using angle information from the contact surface of the grounding leg, and Fig. 3 is FIG. 1 is a schematic layout diagram of a power equipment according to an embodiment of the present invention; a is a front perspective view;
4b is a rear perspective view, FIG. 4 is a control block diagram, and FIG. 5 is a schematic perspective view of the gyro. 5... Arithmetic processing circuit and actuator, 6
a...Plant, angle meter and gyroscope, 7...
Hydraulic actuator, 8... Control circuit and hydraulic motor part, 9... Hydraulic tank, 10... Rotor,
11...Rotating shaft, 12...Inner support frame, 13...Outer support frame, 14...Support shaft, 15...Spring. In addition,
In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a posture control device for a power orthosis that includes an actuator attached to the thigh, lower leg, ankle, etc. and a means for applying power to this actuator, a device is attached to each joint to detect the relative angle of each joint forming a link. an angle meter to be attached to the body, a gyroscope to be attached to the fuselage for detecting an angle reference from the vertical plane, and a deviation signal between the angle of each link with respect to the vertical plane and an angle signal given as a command to be given to the actuator. A posture control device for a power equipment, characterized by comprising a calculation processing circuit for calculating power.