串联弹性执行器的第二扭矩端口：并行集成设计与时间尺度扭矩分配
A Second Torque Port for Series Elastic Actuators: Parallel-Integrated Design and Time-Scale Torque Allocation
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中文总结 AI 辅助
针对串联弹性执行器单一扭矩端口在高频和低幅下的性能局限，本文提出并行集成式SEA（Pi-SEA），通过时间尺度分配扭矩，拓宽跟踪带宽并降低残余误差一个数量级。
中文摘要 AI 辅助
串联弹性执行器只有一个扭矩端口，并为此付出双重代价：齿轮电机必须通过弹簧摆动其自身的反射惯量，因此一旦饱和，其输出幅度随命令频率ω以ω⁻²的速度衰减，而低于传动装置分离摩擦的命令则根本无法到达。本文在负载侧开辟了第二个扭矩端口，将无框直驱微电机与固定刚度弹簧并行放置——即并行集成式SEA（Pi-SEA），其输出扭矩通过弹簧变形和微电流读取，无需传感器——并通过时间尺度而非滤波器设计将命令扭矩分配给两个通道。微扭矩回路是快速子系统，这使得闭环成为奇异扰动系统，并将通道所需的分离转化为需要检查的界限而非需要调节的交越；泄漏的中间范围积分器将稳态负载返回给弹簧；而幅度上限，反向解读，成为匹配弹簧、齿轮电机和微电机与应用所需幅度和频率的闭式设计规则。与SEA相比，Pi-SEA在小幅度下拓宽了跟踪带宽，并将关节对其环境施加的残余误差降低了一个数量级，两者均提升了一个数量级。
英文摘要
A series elastic actuator has a single torque port and pays for it twice: the geared motor must swing its own reflected inertia through the spring, so the amplitude it delivers collapses as $ω^{-2}$ in the command frequency $ω$ once it saturates, while commands below the transmission's breakaway friction never arrive at all. This letter opens a second torque port on the load side, placing a frameless direct-drive micro motor in parallel with a fixed-stiffness spring -- a parallel-integrated SEA, or Pi-SEA, whose delivered torque is read from spring deflection and micro current without a sensor -- and dividing the commanded torque between the two channels by time scale rather than by filter design. The micro torque loop is the fast subsystem, which makes the closed loop singularly perturbed and turns the separation the channels need into a bound to check rather than a crossover to tune; a leaky mid-ranging integrator returns the steady load to the spring; and the amplitude ceiling, read backwards, becomes a closed-form sizing rule that matches spring, geared motor and micro motor to the amplitudes and frequencies an application asks for. Against SEAs, the Pi-SEA widens the tracked band at small amplitudes and lowers the residual the joint imposes on its environment, each by an order of magnitude.
发表机构
- Beihang University（北京航空航天大学）
机构由 AI 辅助整理，请以论文原文为准。
