A stable transition from free-motion to contact phase is extremely significant for a UAV interacting with its objects and environment. Oscillations may occur at the contact point if the force controller of the UAV fails to accommodate to the environment parameters, which are usually unknown to the UAV. In this paper, the acceleration feedback control is proposed to enhance the robustness of a classic force controller. This intends to achieve a smooth and stable contact transition of the UAV while interacting with different stiffness environments with non-zero approaching velocity. Extensive flight tests are conducted on a quadrotor UAV to verify the performance of the proposed algorithm with respect to different-stiffness environments. The experimental results are also compared with those without the acceleration feedback enhancement, to demonstrate the improvement of the proposed scheme.

从自由运动到接触阶段的稳定过渡对于无人机与其物体和环境的相互作用非常重要。如果无人机的力控制器无法适应环境参数（通常对于无人机而言是未知的），则可能在接触点发生振荡。在本文中，提出了加速度反馈控制以增强经典力控制器的鲁棒性。这旨在实现无人机的平稳平稳的接触过渡，同时以非零的接近速度与不同的刚度环境相互作用。在四旋翼无人机上进行了广泛的飞行测试，以验证所提出算法相对于不同刚度环境的性能。还将实验结果与没有加速反馈增强的结果进行了比较，