In this paper, fuzzy-backstepping control method is utilized to control quadruped robots. The backstepping control method is inherently a stable control method since its design procedure is based on the Lyapunov stability theory. However, for an acceptable performance of this controller, the feedback gains must be appropriately selected. Using fuzzy systems, these gains are adaptively tuned for best performance of the robot against uncertainties in system parameters, external disturbances, and measurement noises. Next, the stability of the robot is investigated using the Poincaré map stability criterion. This is because the Lyapunov method does not guarantee stability for the periodic systems such as legged robots. The proposed method is simulated on the highly nonlinear equations of a quadruped robot. The performance of the proposed method is compared with the backstepping control to show the importance of fine-tuning the parameters using fuzzy system. The simulating results for a nine-degree-of-freedom quadruped robot show very good performance of the proposed control method, especially against uncertainties in system parameters, external disturbances, and measurement noises, which are common in robots.

中文翻译：

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四足机器人的模糊反推控制

本文采用模糊反推控制方法控制四足机器人。反步控制方法本质上是一种稳定的控制方法，因为其设计过程基于Lyapunov稳定性理论。但是，对于该控制装置的可接受的性能，反馈增益必须适当地选择。使用模糊系统，可以针对系统参数，外部干扰和测量噪声的不确定性，对这些增益进行自适应调整，以实现机器人的最佳性能。接下来，使用庞加莱地图稳定性准则研究机器人的稳定性。这是因为Lyapunov方法不能保证腿式机器人等周期系统的稳定性。该方法在四足机器人的高度非线性方程组上进行了仿真。将所提方法的性能与反推控制进行了比较，以表明使用模糊系统微调参数的重要性。九自由度四足机器人的仿真结果表明，所提出的控制方法具有很好的性能，特别是针对机器人常见的系统参数，外部干扰和测量噪声的不确定性。