CN105616041A

CN105616041A - Impedance control system for artificial limbs

Info

Publication number: CN105616041A
Application number: CN201410622921.1A
Authority: CN
Inventors: 赵俭
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-08
Filing date: 2014-11-08
Publication date: 2016-06-01

Abstract

The invention belongs to the technical field of electricity and particularly relates to an impedance control system for artificial limbs. By the aid of the impedance control system for the artificial limbs, a wearer can walk more comfortably and naturally and adapt to different paces and road conditions. The system comprises a PID fuzzy controller, a foot angle sensor, a single-chip microcomputer, an A/D converter, a protection device, a switch, a speed sensor, a buck switching mode power supply and a comparator. The system is characterized in that the foot angle sensor is connected with the PID fuzzy controller through the A/D converter, the single-chip microcomputer is connected with the PID fuzzy controller through the switch, and the PID fuzzy controller is also connected with the protection device, the speed sensor, the buck switching mode power supply and the comparator.

Description

A kind of artificial limb impedance control system

Technical field

The invention belongs to electroporation field, particularly relate to a kind of artificial limb control system.

Background technology

Due to ankle and foot human body is stood, the motion of the basic living such as walking has indispensable effect, and the exploitation of type ankle-foot prosthesis is always up the hot subject in rehabilitation engineering subject with research. Traditional type ankle-foot prosthesis adopts pure passive or semi-passive control form mostly, supports in mutually in gait and only relies on being regulated by dynamic elasticity or limited damping of structure, and release locked by the joint of intimate machinery, auxiliary wearer realizes walking and standing activities. Tradition is passive/semi-passive type ankle-foot prosthesis has simple in construction, a feature from heavy and light, high energy efficiency, but when cannot provide walking for wearer required upwards with active force forward, the impedance behavior that biological joint has can not be realized. Clinical research shows, disadvantages mentioned above can cause the Nonsymmetrical movement between wearer artificial limb and strong limb, causes its energy of 10-60% more about than the many consumption of normal person under same pace. This has had a strong impact on the walking comfort level of wearer, reduces walking speed and sphere of action.

Summary of the invention

The present invention is aiming at the problems referred to above, it is provided that one can make wearer walking more comfortable, natural, and adapts to a kind of artificial limb impedance control system of different leg speeds and road conditions.

For achieving the above object; the present invention adopts the following technical scheme that; the present invention includes PID fuzzy controller, foot angle sensor, single-chip microcomputer, A/D converter, protection device, switch, velocity sensor, adjusting and voltage-reduction switch power supply and comparator; it is characterized in that: foot angle sensor connects PID fuzzy controller by A/D converter; single-chip microcomputer connects PID fuzzy controller by switch, and PID fuzzy controller is also connected with protection device, velocity sensor, adjusting and voltage-reduction switch power supply and comparator.

As another kind of preferred version, described single-chip microcomputer is AT89S52 single-chip microcomputer.

Beneficial effect of the present invention.

The present invention, according to the gait rule in level walking, mainly includes ankle joint moment of torsion, angle range and joint impedance variation rule thereof. In level walking, single gait cycle generally lands to the second time of homonymy heel by heelstrike. Contiguity constraint according to foot changes, and gait can be divided into swing and support phase two parts. Adopt fuzzy PID control strategy that its type ankle-foot prosthesis model of position servo control of active type ankle-foot prosthesis can be reappeared default ankle joint impedance variation curve, and there is the feature of low-power consumption.

Accompanying drawing explanation

Below in conjunction with the drawings and specific embodiments, the present invention will be further described. Scope is not only limited to the statement of herein below.

Fig. 1 is principle of the invention block diagram.

Detailed description of the invention

As shown in the figure; the present invention includes PID fuzzy controller, foot angle sensor, single-chip microcomputer, A/D converter, protection device, switch, velocity sensor, adjusting and voltage-reduction switch power supply and comparator; it is characterized in that: foot angle sensor connects PID fuzzy controller by A/D converter; single-chip microcomputer connects PID fuzzy controller by switch, and PID fuzzy controller is also connected with protection device, velocity sensor, adjusting and voltage-reduction switch power supply and comparator.

Target for clear and definite joint motions Yu impedance control, it is necessary first to understand the podarthral biomechanics characteristic of human body ankle, especially its gait rule in level walking, mainly include ankle joint moment of torsion, angle range and joint impedance variation rule thereof. In level walking, single gait cycle generally lands to the second time of homonymy heel by heelstrike. Contiguity constraint according to foot changes, and gait can be divided into swing and support phase two parts. Wherein, being in the supporting leg supported in mutually is that human locomotion carries 65 for stablizing, effectively supporting, and supporting phase control is that type ankle-foot prosthesis driving controls mainly to study a little. Although ankle joint torque, rotation curve high complexity, but the phase plane constituted at both can obtain joint feature impedance curve. This slope of a curve represents biological joint joint impedance magnitude at the volley, and the area that curve surrounds represents the mechanical energy of ankle joints of foot moment output. In a gait cycle, model of human ankle presents the passive behavior of periodically variable class, and with special angle is divided into that joint impedance is dramatically different two sections. By the motor behavior of ankle joint in the walking of level land, non-linear passive flexible member and the linear combination of one section of lasting moment of torsion can be reduced to accordingly.

Existing joint driver small and special electric machine etc. is difficult to reach the power density that human body ankle and foot has, and selects that heavy-duty motor then general size is big, quality weight, it is difficult to meet physical dimension and the weight demands of powered prosthesis. Additionally, the joint of artificial limb directly driven with conventional drives such as motors has bigger mechanical impedance and inertia, it is impossible to bear prosthetic foot with impact when contacting to earth. The intrinsic high-impedance behavior of driver also seriously constrains the actual effect of joint impedance algorithms, it is impossible to meet the function needs that joint of artificial limb impedance regulates. Accordingly, it would be desirable to tradition type ankle-foot prosthesis joint drive form is improved, take into full account the impact on artificial limb system motor control of the driver own limitations.

The structure that main passive hybrid driving method is power ankle foot prosthesis provides new space with control algolithm research. Adopt the joint of artificial limb of this driving method, control the motion of joint of artificial limb the output impedance in active adjustment joint with the series elastic driver that power control performance is excellent. And joint impedance is passively regulated in support mutually with the passive device that parameter is suitable, reduce the power grade driving load, minimizing driver instantaneous power demands, reduction driver of series elastic driver, thus the power improving joint of artificial limb controls response bandwidth, improves the overall efficiency of artificial limb system, the volume reducing drive system and weight.

The power ankle foot prosthesis structure of main passive combination drive. The drive mechanism being made up of synchronous pulley and ball-screw, under the driving of direct current generator, promotes the serial spring plate of prosthetic foot heel that foot is applied driving torque, thus constituting a series elastic driver (SEA) rotated. And at the installed in front of artificial limb anklebone joint Hookean spring one piece in parallel with series elastic driver. This parallel springs shares the driving load of series connection executor mutually supporting, and improves the efficiency of joint of artificial limb. And promote the output impedance of joint of artificial limb when artificial limb dorsiflex, change joint impedance control passively. In order to the motor control not affected in other stages of gait, Cai this parallel connection leaf spring only onset when foot dorsiflex.

Claims

1. an artificial limb impedance control system; including PID fuzzy controller, foot angle sensor, single-chip microcomputer, A/D converter, protection device, switch, velocity sensor, adjusting and voltage-reduction switch power supply and comparator; it is characterized in that: foot angle sensor connects PID fuzzy controller by A/D converter; single-chip microcomputer connects PID fuzzy controller by switch, and PID fuzzy controller is also connected with protection device, velocity sensor, adjusting and voltage-reduction switch power supply and comparator.

2. a kind of artificial limb impedance control system according to claim 1, it is characterised in that: described single-chip microcomputer is AT89S52 single-chip microcomputer.