Walking Motion Assistance Phase Control During Thigh Reverse Swings
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Solution Overview
Problem
Existing gait motion assisting apparatuses struggle to provide smooth gait assistance when users with leg disabilities or paralysis experience unintentional thigh reverse swing phenomena during a gait cycle, leading to rapid changes in actuator output.
Innovation Solution
The apparatus incorporates a thigh phase angle calculating unit that performs latest data transmission when conditions are met, storing a reference phase angle only when deviations are within a predetermined threshold, ensuring smooth gait assistance by stabilizing actuator output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the thigh phase angle is calculated based on hip joint angle and angular velocity at each sampling timing, then the gait motion timing can be recognized accurately, but rapid changes in actuator output occur during thigh reverse swing phenomena
Solution Approach 1:
The system performs preliminary detection of thigh reverse swing phenomena by monitoring the relationship between consecutive thigh phase angles before actuator output changes occur. When a reverse swing is detected (θ(k) < θ(k-1)), the system preemptively adjusts or suppresses actuator output to prevent rapid changes, thereby maintaining stability while preserving accurate gait timing recognition capability
Solution Approach 2:
The system implements feedback control by continuously monitoring the thigh phase angle sequence and using this information to adjust actuator output. The control unit compares current thigh phase angle with previous values, and when reverse swing is detected, modifies the actuator command accordingly. This feedback mechanism maintains both measurement precision and output stability by adapting actuator behavior based on detected gait anomalies
2Device complexity
If the apparatus uses thigh phase angle calculation instead of lower leg motion detection, then the structure is simplified, but smooth gait assistance is difficult to maintain during reverse swings
Solution Approach 1:
The system performs preliminary detection of reverse swing conditions by monitoring thigh phase angle sequences before they affect gait assistance smoothness. When reverse swing is detected (consecutive phase angles decrease), the system preemptively adjusts control parameters or suppresses actuator output to prevent disturbances, thereby maintaining smooth gait assistance while preserving the simplified thigh-based detection structure
Solution Approach 2:
The system implements feedback control using thigh phase angle information to maintain gait assistance smoothness. The control unit continuously monitors phase angle sequences, and when reverse swing is detected, adjusts actuator output accordingly. This feedback mechanism allows the simplified detection structure to maintain stable and smooth gait assistance by adapting to detected anomalies in real-time
Data Source
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AI summary
In a gait motion assisting apparatus (100) of the present invention, a thigh phase angle calculating unit (550) has a latest data transmission process to transmit a thigh phase angle (ϕ(k)) at sampling timing (S(k)) (k is an integer of 1 or more) to a gait motion timing calculating unit (560) and store the same as reference thigh phase angle (ϕc) and a stored data transmission process to transmit, instead of the thigh phase angle (ϕ(k)), the currently stored reference thigh phase angle (ϕc) to the gait motion timing calculating unit (560) and keep the reference thigh phase angle (ϕc), performs the stored data transmission process only when conditions are satisfied such that a thigh phase angle (ϕ)at one sampling timing (S) is smaller than the currently stored reference thigh phase angle (ϕc) and an absolute value of a deviation therebetween is equal to or less than a predetermined threshold, and performs the latest data transmission process in other cases.