Based on the concept of virtual constraint, we present a method to design output functions analytically for tune-invariant gait, and design a feedback linearization controller which transforms the system into a loop of double integrator.

• 基于虚拟约束的概念，提出时不变步态的输出函数解析设计方法，设计了反馈线性化控制器，将系统转化为双积分环节。