Intelligent control of a smart walker and its performance evaluation

Area of Science:

• Robotics
• Biomechanics
• Assistive Technology

Background:

• Smart walkers offer enhanced mobility and gait assistance through force-dependent, intelligent control.
• Technological advancements enable sophisticated control systems for improved user interaction.

Purpose of the Study:

• To develop an intelligent rule-based controller for a smart walker.
• To ensure smooth interaction between the user and the smart walker.
• To evaluate the controller's performance against an admittance-based system.

Main Methods:

• A rule-based mapping was developed between interaction force (measured by load cell) and walker acceleration.
• The proposed controller was evaluated by ten healthy subjects.
• Performance was compared to a standard admittance-based control system.

Main Results:

• No significant differences were found in user experience, velocity profiles, or cost of transportation between the two control systems.
• The admittance-based system required a significantly lower average interaction force (1.2N) to maintain a 1m/s target speed (p = 0.002).
• Metabolic data suggested smart walker-assisted gait can considerably reduce the metabolic demand compared to traditional four-legged walkers.

Conclusions:

• The developed rule-based controller facilitates smooth user-walker interaction.
• While comparable in many aspects, the admittance-based system showed a slight advantage in reduced interaction force.
• Smart walker technology holds significant promise for reducing the metabolic burden of walking for individuals with mobility impairments.