A compact dynamic joint mechanism and its portable lower limb assisting device

Abstract

The invention relates to a compact type power joint mechanism and portable type lower limb power assisting equipment. The compact type power joint mechanism comprises a joint main body and a power device arranged on the joint main body, wherein the joint main body comprises an upper arm structure, a center beam perpendicularly connected with the upper arm structure, and a lower arm structure rotationally connected with the center beam; the power device comprises a power part and a speed reducing mechanism which is in transmission connection with the power output end of the power part, whereinthe power part is fixedly connected to the upper arm structure, the power output end of the speed reducing mechanism is in transmission connection with the lower arm structure, so that the power partdrives the lower arm structure to rotate relative to the upper arm structure. According to the compact type power joint mechanism and the portable type lower limb power assisting equipment, the powerperformance of exoskeleton are improved, the cost is low, and the reliability is high; and the mechanism is compact in structure, light in weight and small in size.

Description

technical field [0001] The invention relates to a wearable device, more specifically a compact dynamic joint mechanism and a portable lower limb assisting device. Background technique [0002] The field of robotics widely requires the application of power joints. The exoskeleton robots used for human body wearables generally have multiple power joints. Motor rotary encoder; at the same time, the power joint needs to be small in size, light in weight and low in cost. [0003] In the prior art, generally, a flat disc motor is used for the motor, and a harmonic reducer is used for the reducer, so that the axial dimension of the power joint is smaller and the weight is relatively light. Under normal circumstances, the power joint chooses an integrated harmonic reducer, that is, a standard integrated harmonic product integrated with a flexible spline and steel wheel, such as the 2011 master thesis of Harbin Institute of Technology "Exoskeleton Lower Limb Assisted Robot Technolog...

AI Technical Summary

Problems solved by technology

Under normal circumstances, the power joint chooses an integrated harmonic reducer, that is, a standard integrated harmonic product integrated with a flexible spline and steel wheel, such as the 2011 master thesis of Harbin Institute of Technology "Exoskeleton Lower Limb Assisted Robot Technology Research" This scheme is disclosed in the paper "Mechanical Design of the Hanyang Exoskeleton Assistive Robot (HEXAR)" ICCAS2014 also discloses a similar scheme; these schemes lead to large weight and large volume of dynamic joints

The patent US9532894 "HIGH DENSITY ACTUATOR WITHMINIMAL LATERAL TORSION" discloses that the harmonic deceleration separation component is used to design a compact power joint with light weight and small size, but this design uses an ultra-thin harmonic reducer, and the torque of this type of harmonic reducer is relatively large Small size, high cost and low maturity. In addition, the patent does not have a motor encoder, which is not conducive to high-performance control of the motor

[0004] In the prior art, the high-performance drive of the motor requires the use of a rotary encoder. The existing solutions mostly use photoelectric rotary encoders, which are large in size and high in cost, resulting in complicated design of dynamic joints; the paper "Mechanical Design of the Hanyang Exoskeleton Assistive Robot (HEXAR) "ICCAS2014, the paper "Design of electrically actuated lower extremity exoskeleton" (Advanced Robotics, Vol.20, No.9, pp.967-988 (2006)) and Chinese patent 201620267410.7 all disclose the same scheme

[0005] In the prior art, some torque sensors are used to measure the output torque of the motor. For example, the paper "Mechanical Design of the Hanyang Exoskeleton Assistive Robot (HEXAR)" ICCAS2014 discloses such a scheme. This scheme has strict requirements for installation accuracy, which is difficult to guarantee in the actual environment. , the above papers did not disclose how to solve the problem of installation accuracy; some use pressure sensors to measure the output torque of the motor, the paper "Design of electrically actuated lower extremity exoskeleton" (Advanced Robotics, Vol.20, No.9, pp.967–988( 2006)) disclosed this kind of scheme, the structure of this scheme is relatively complex, the requirements for installation accuracy are very strict, and the cost is relatively high, and the scheme also fails to disclose how to ensure the installation accuracy

[0006] In the prior art, the dynamic joint does not include a solution for measuring the relative angle of the upper arm and the lower arm. Generally, the motor encoder is used to estimate the relative angle of the upper and lower arms. The problem with this solution is that calibration is required every time the power is turned on, and the accuracy is difficult to guarantee; Neither the paper "Mechanical Design of the Hanyang Exoskeleton Assistive Robot (HEXAR)" ICCAS2014 nor the paper "Design of an electrically actuated lower extremity exoskeleton" (Advanced Robotics, Vol.20, No.9, pp.967–988(2006)) disclosed A solution for measuring the relative angle of the upper and lower arms

[0007] In the prior art, the patent 201611189733.X mentions a power joint device for exoskeleton, the device is equipped with a torque sensor, a motor encoder and an angle sensor. In this solution, there are gaps and large volumes in the structure of the torque sensor. Unsightly, the connecting part of the upper and lower arms and the harmonic reducer adopts a single-board structure, and the rigidity is difficult to achieve under the same volume and weight.

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