**Jianyong Qian, Qi Su \*, Fu Zhang, Yun Ma, Zifan Fang and Bing Xu**

State Key Laboratory of Fluid Power & Mechatronic Systems, Zhejiang University, Hangzhou 310027, China; 21825065@zju.edu.cn (J.Q.); zgzhangfu@outlook.com (F.Z.); 21825218@zju.edu.cn (Y.M.); zerofang@zju.edu.cn (Z.F.); bxu@zju.edu.cn (B.X.)

**\*** Correspondence: suqi@zju.edu.cn

Received: 1 November 2019; Accepted: 19 December 2019; Published: 8 January 2020

**Abstract:** Modern large-scale manipulators with hydraulic actuation like mobile concrete pump manipulators are increasingly used in industrial, construction, and other fields. Due to the large span of these manipulators, the static deformation accumulation to the endpoint has seriously affected the precise control of the endpoint. In this paper, we propose a static deformation-compensation method based on inclination sensor feedback for large-scale manipulators to reduce the deviation of the endpoint. Compared with the finite element method, this method does not need to consider many boundary conditions that are uncertain for flexible manipulators in most situations. It has appropriate accuracy and is universal for large-scale manipulators of different sizes and working under different loads. Based on a 24m-3R mobile concrete pump manipulator, the parametric simulation is carried out. The reliability of the static deformation-compensation method is verified, and the error is analyzed. The validity of the static deformation-compensation method is verified by comparing the theoretical endpoint position with the actual endpoint position after static deformation compensation. The compensation error under different loads is obtained, and the universality of the compensation method for different loads is verified.

**Keywords:** static deformation; inclination sensor; large-scale manipulator; concrete pump; endpoint deviation
