Advanced 3D Control Techniques for Powered Wheelchairs

在美国，超过20万人使用电动轮椅（EPWs）作为他们的主要移动方式。电动轮椅为下肢和上肢残疾的人提供功能性移动。虽然电动轮椅在过去的20年里取得了很大的进步，但自20世纪80年代初以来，控制算法几乎没有变化。简单的比例积分（PI）控制器上使用的电动轮椅速度控制是过时的，并没有表现出良好的干扰，传感器的不确定性和负载变化。此外，轮椅使用者在户外驾驶时可能会遇到不同的环境和路况。PI已经成功地实现了一个pushrim激活动力辅助轮椅的共享控制系统。此外，运动学和动力学模型的EPW开发，以模拟轮椅的运动和实验结果进行了验证。通过这些初步研究，PI建议为电动轮椅设计一个鲁棒控制器，包括速度控制和牵引力控制。速度控制算法的基础上改进的轮椅模型，旨在提高安全性和有效性的EPWs面对外部干扰，参数变化和不确定性。处理车轮打滑和轮椅被卡住的情况的牵引力控制算法将增加移动性并确保在不太有利的表面条件（即，湿草地，结冰的人行道，雪）。最后，他们建议在飞行员环境中测试算法，包括动态稳定性测试，越障能力测试，在脚轮方向干扰下的操作，室内阈值测试，在坡道上，在横坡上，在草地上，在粗糙表面和光滑表面上的操作。这项试点研究将提供进行大规模试验的手段，旨在在电动轮椅上实施强大的控制器，并测试对安全性，流动性和社区参与的影响。

Over 200,000 people in the United States use electric-powered wheelchairs (EPWs) as their primary means of mobility. Electric-powered wheelchairs provide functional mobility for people with both lower and upper extremity impairments. While electric powered wheelchairs have made great advances over the past 20 years, the control algorithms remain virtually unchanged since the early 1980s. The simple proportional-integral (PI) controller used on electric-powered wheelchairs for velocity control is antiquated, and does not perform well with disturbances, sensor uncertainties and load variations. In addition, wheelchair users may encounter different environments and road conditions when driving outdoors. The PIs have successfully implemented the shared control system for a pushrim activated power assisted wheelchair. In addition, kinematic and dynamic models of an EPW were developed to simulate the wheelchair motion and were validated by experimental results. With these preliminary studies, the PIs propose to design a robust controller for electric powered wheelchairs that includes velocity control and traction control. The velocity control algorithm based on an improved wheelchair model aims to improve the safety and efficacy of EPWs in the face of external disturbances, parameter variations and uncertainties. The traction control algorithm coping with wheel slips and cases where the wheelchair becomes stuck will increase mobility and ensure safe navigation under less favorable surface conditions (i.e., wet grass, iced sidewalk, snow). Finally, they propose to test the algorithms in a pilot setting, including dynamic stability test, obstacle climbing ability test, operation under caster orientation disturbances, indoor threshold test, operation on ramps, on cross slopes, on grass, on rough surfaces and slippery surfaces. This pilot study will provide the means to conduct a large-scale trial designed to implement robust controllers in electric powered wheelchairs and test the effect on safety, mobility, and community participation.