Exoskeleton HMI Using Gesture and Force Sensors
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Solution Overview
Problem
Powered lower extremity orthotic devices struggle to independently initiate steps for users with mobility disorders, particularly paralyzed individuals, as they cannot use button inputs due to crutches or walkers, necessitating a Human Machine Interface (HMI) that interprets natural user motion to control exoskeletons safely and effectively.
Innovation Solution
A system and method that uses upper body gestures and force signals to determine desired leg movements, employing sensors like inertial measurement units, angle sensors, and force distribution sensors to automatically regulate powered lower extremity orthotic components, enabling users to initiate steps and perform mobility tasks naturally, with safety checks and feedback mechanisms to ensure safe transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If button input or motion following is used for step initiation, then the device can be controlled, but users with paralysis or those holding support devices cannot independently initiate steps
Solution Approach 1:
The patent replaces traditional mechanical button input systems with a sensor-based detection system that monitors upper body motion, shank angle, and force distribution. This substitution enables users who cannot physically press buttons to initiate steps through natural body movements, thereby improving ease of operation while maintaining user independence.
Solution Approach 2:
The system enables users to control the orthotic device through their own natural body movements without requiring external assistance or complex manual inputs. By detecting self-generated motions such as upper body gestures or weight shifts, the system allows users to independently initiate and control stepping actions, embodying the self-service principle.
2Stability of the object's composition
If the device uses stiff mechanics or active control to maintain position, then stability is improved, but natural user intent detection becomes more difficult
Solution Approach 1:
The patent introduces intermediate sensor systems (such as force distribution sensors and angle sensors) that act as mediators between the user's natural movements and the stiff controlled device. These intermediaries detect subtle user intentions through proxies like shank angle changes or foot force distribution, enabling intent recognition without compromising device stability.
Solution Approach 2:
The system detects user intent by observing movements in alternative dimensions rather than directly measuring desired leg motion. For example, it monitors upper body gestures, shank angle variations, or force distribution patterns as proxy indicators of user intention, effectively translating movements from one dimension to another to overcome the stiffness barrier.
3Reliability
If multiple sensors and safety checks are implemented, then safety and control precision are improved, but device complexity increases
Solution Approach 1:
The patent divides the control system into segmented functional modules: upper body gesture detection, shank angle monitoring, force distribution sensing, and safety verification. Each module independently processes specific aspects of user input and safety, allowing the complex system to be managed through modular components that can be developed, tested, and maintained separately.
Data Source
AI summary
A lower extremity orthotic control system determines a movement desired by a user, particularly with a user employing gestures or other signals to convey or express their intent to the system, and automatically regulates the sequential operation of powered lower extremity orthotic components. In a particular application, the orientation of a stance leg is used to determine when the user wants to initiate a step, as well as when the user is in a safe position from which to take a step. The invention has particular applicability for use in enabling a paraplegic user to walk through a controlled operation of a human exoskeleton coupled to the user's lower limbs. A controller receives inputs regarding a motion desired by the user, determines the desired motion and then controls the movement of the user's legs or limbs through actuation of the exoskeleton.