Calibrating Mobility Device Control Profiles for Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Calibrating mobility devices, such as powered wheelchairs and scooters, to ensure stability and user comfort is challenging due to the need for precise regulation of acceleration and turning rates, which is often tedious and requires technical expertise, and existing sensor-based solutions are costly and complex.
Innovation Solution
A system that temporarily attaches sensors to the mobility device to collect data during a prescribed routine, determining stability and producing a control profile that restricts output variables associated with instability, allowing for intuitive and non-expert calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are permanently installed to detect instability, then mobility device stability is improved, but device complexity and cost increase
Solution Approach 1:
The calibration system performs stability characterization before the mobility device is delivered to the user. A therapist or technician conducts a preliminary calibration session where the system collects data about the user's weight, center of gravity, and stability characteristics. Based on this preliminary action, control profiles are pre-configured to prevent instability, so that during normal operation, no additional sensors are needed to detect instability in real-time.
Solution Approach 2:
Instead of using expensive permanent sensors to detect instability during operation, the system creates a digital model or copy of the stability characteristics during calibration. The control profile is generated as a virtual representation of safe operating parameters, which then guides the controller to prevent instability without requiring continuous physical sensing.
2Adaptability or versatility
If manual calibration is performed by entering parameters, then customization to user needs is improved, but ease of operation deteriorates due to technical expertise required
Solution Approach 1:
The calibration system is designed to be self-calibrating through an interactive process. During calibration, the system guides the user through a series of automated maneuvers (acceleration, turning, deceleration) and automatically collects data about the device's response and the user's characteristics. The controller then automatically generates the control profile based on this collected data, eliminating the need for the therapist to manually enter technical parameters or have expertise in control theory.
Solution Approach 2:
The system incorporates real-time feedback during the calibration process. As the mobility device performs test maneuvers, sensors collect data about actual performance, and the system uses this feedback to automatically adjust and refine the control profile. This closed-loop feedback mechanism ensures accurate user-specific calibration without requiring the operator to understand complex control parameters.
3Manufacturing precision
If multiple trials are conducted to optimize performance, then control precision is improved, but loss of time increases
Solution Approach 1:
The system performs comprehensive stability characterization in a single preliminary calibration session rather than requiring multiple separate trials. During this initial calibration, the system systematically tests various operating conditions (different velocities, turning rates, acceleration levels) and collects all necessary data to generate a complete control profile. This preliminary action consolidates what would otherwise require multiple time-consuming trials into one efficient process.
Solution Approach 2:
The calibration process is designed as a continuous sequence of test maneuvers rather than discrete, separate trials. The mobility device performs a series of connected actions (acceleration followed by turning followed by deceleration) without interruption, allowing the system to collect comprehensive stability data in one continuous flow. This continuous calibration approach maintains control precision while minimizing the total time required compared to multiple separate trials.
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A method and system for calibrating a control profile of a controller having at least one output variable used to control the operation of a mobility device. The calibration system controls the mobility device according to a prescribed routine under a range of changes of values of the output variable. One or more sensors provided, either temporarily or permanently, on the mobility device sense operational parameters of the mobility device and send sensed data to the calibration system. The calibration system determines mobility device stability associated with the changes of the at least one output variable based on the sensed data and produces a control profile that restricts a controller from outputting changes of values of the output variable associated with mobility device instability.