To improve the trajectory tracking performance of a complex nonlinear robotic system, a velocity-free adaptive time delay control is proposed. First, considering that conventional time delay control (TDC) may cause large time delay estimation (TDE) error under nonlinear friction, a TDC with gradient estimator is designed. Next, since it is complicated and time-consuming to adjust gains manually, an adaptive law is designed to estimate the gain of the gradient. Finally, in order to avoid the measurement of velocity and acceleration in the controller while enabling the robot to implement position tracking, an observer is designed. The proposed control can not only offset the nonlinear terms in the complex dynamics of the robotic system but also reduce the TDE error, estimate the gain of the gradient online, and avoid the measurement of velocity and acceleration. The stability of the system is analyzed via Lyapunov function. Simulations are conducted on a 2-DOF robot to verify the effectiveness of the proposed control.

中文翻译：

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机器人系统无速度自适应时滞控制

为了提高复杂非线性机器人系统的轨迹跟踪性能，提出了一种无速度自适应时滞控制方法。首先，考虑到传统的时滞控制（TDC）可能在非线性摩擦下引起较大的时延估计（TDE）误差，因此设计了带有梯度估计器的TDC。接下来，由于手动调节增益既复杂又费时，因此设计了一种自适应定律来估算梯度的增益。最后，为了避免在控制器中测量速度和加速度，同时使机器人能够执行位置跟踪，设计了一个观察器。所提出的控制不仅可以抵消机器人系统复杂动力学中的非线性项，而且可以减少TDE误差，在线估算梯度的增益，并避免测量速度和加速度。通过Lyapunov函数分析系统的稳定性。在2自由度机器人上进行了仿真，以验证所提出控制的有效性。