Purpose End-effector positioning accuracy in wheeled mobile manipulators (WMMs) is degraded by chassis compliance, which is primarily caused by pneumatic tire deformation. To address this issue, this paper aims to model the chassis pose errors induced by such compliance as a key step to improve the absolute positioning accuracy of the WMM end-effector. Design/methodology/approach To characterize the chassis compliance arising from pneumatic tire deformation, a novel modeling method is proposed. It begins by modeling interactions within the WMM to quantify the loads on each tire. A static tire model is then developed to predict tire deformation under these loads, from which the induced chassis pose variations are derived, ultimately allowing for the calculation of actual end-effector positioning. Findings The simulation results show the correctness and effectiveness of the proposed method. The experimental results demonstrate that the proposed method achieves reasonable computational accuracy for the chassis pose variation. Meanwhile, the proposed chassis compliance model can improve the end-effector positioning accuracy of the WMM by at least 62.9%. Originality/value A novel chassis compliance model for the WMMs with pneumatic tires is proposed and validated. It can provide a theoretical basis for high-precision tasks of WMMs and is beneficial for various applications, such as manufacturing and assembly.
Liu et al. (Mon,) studied this question.