Wearable Chair Seating Support with Angle-Based Link Locking
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Solution Overview
Problem
Wearable robots face stability issues due to their weight and complex control mechanisms, and when a wearer sits, the center of gravity deviates, leading to instability, while the fixed links interfere with walking when standing up.
Innovation Solution
A seating support device for wearable chairs that fixes femoral and crural links at a seating angle, allowing them to rotate freely when standing, using a housing, sliding part, limiting device, and cam mechanism to prevent sliding and adjust the seating angle, ensuring stability and free movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the femoral link and crural link are fixed to prevent rotation at seating angle, then stability is improved, but the links cannot rotate freely when standing up
Solution Approach 1:
The patent applies a dynamic limiting device that changes state based on operating conditions. The device includes a sliding part that can slide along the crural link and a limiting mechanism with protrusions and grooves that engage at specific angles. When the knee joint reaches the seating angle, the limiting device engages to fix the links and prevent rotation, providing stability. When the angle exceeds the seating angle, the limiting device disengages, allowing free rotation for standing and walking movements.
Solution Approach 2:
The patent changes the operational parameters of the link system by introducing a variable limiting mechanism. The limiting device has different engagement states corresponding to different knee joint angles. At the seating angle parameter, the device transitions from a free-state to a locked-state, changing the degrees of freedom of the system. This parameter-based state change allows the system to maintain stability during sitting while enabling mobility during standing.
2Stability of the object's composition
If the center of gravity is fixed, then stability is improved, but the device cannot adapt to different postures
Solution Approach 1:
The patent implements a dynamic posture adaptation mechanism through the limiting device that selectively engages based on knee joint angle. The device includes a sliding part that moves along the crural link and a limiting mechanism with multiple protrusions and grooves. When the knee joint is at or below the seating angle, the limiting device engages to stabilize the center of gravity. When the knee joint exceeds the seating angle during standing or walking, the limiting device disengages, allowing the center of gravity to shift naturally with body movement, thus adapting to different postures.
Solution Approach 2:
The patent segments the operational range of the knee joint into distinct zones: a seated zone where the limiting device engages for stability, and a standing/walking zone where the device disengages for freedom of movement. The limiting device is divided into multiple components including the sliding part, limiting protrusions, and engagement grooves that work together to provide posture-specific control. This segmentation allows the system to optimize performance for different postures independently.
Data Source
AI summary
A seating support device of a wearable chair includes a femoral link extending in a direction where a femoral region extends and configured to be connected with the femoral region, a crural link extending in a direction where a crural region extends, and configured to be connected with the crural region, and including a housing that is coupled at an upper end thereof to a lower end of the femoral link to be rotatable relative thereto and a sliding part that is slidably coupled to the housing in a direction in which the housing extends, and a limiting device operated in conjunction with a relative rotation between the femoral link and the crural link to allow the sliding part to slide vertically and to prevent sliding between the sliding part and the housing in a state where an angle between the femoral link and the crural link is a seating angle.