变形履带轮椅机器人的张紧力最优估计和越障能力分析

Optimal Tension Estimation and Obstacle-Negotiation Ability Analysis on Deformable Tracked Wheelchair Robot

针对一种新型变形履带机构的轮椅机器人,提出了一种动态确定履带张紧力大小的最优估计算法.相对于传统的恒定张紧力履带式移动机构,动态确定张紧力显著地降低了功率损耗.考虑到张紧力的建模复杂性,文中采用模糊决策算法,将影响张紧力的主要因素输入模糊决策模块.然后结合最小二乘法得到履带张紧力的最优估计算法.鉴于轮椅机器人越障过程中移动速度较慢的特点,结合张紧力最优估计算法结果对轮椅机器人上楼梯起始阶段进行了静力学建模.仿真结果证明了利用张紧力估计算法的越障轮椅机构能够平稳爬楼梯,同时也表明了动态张紧力算法大大降低了驱动功率损耗.

An optimal estimation method is developed to dynamically determine track tension for a new type of deformable tracked wheelchair robot. Compared with traditional tracked mobile mechanism which keeps track tension constant, it can reduce power consumption obviously to determine tension dynamically. Considering the complexity in track tension modeling, a fuzzy logic decision making method is developed, which uses main influential factors on the track tension as its inputs. Then combining with least square method, an optimal estimation algorithm of track tension is obtained. Because of the low speed feature of the process when the wheelchair negotiates obstacle, a statics model of the wheelchair for the initial stage of climbing stairs is developed according to the result of the optimal track tension estimation algorithm. Simulation result proves that the wheelchair can climb stairs stably when it takes advantage of tension estimation algorithm. At the same time, it also shows that the power consumption is reduced greatly by dynamically determining the track tension.