Modeling and Sliding Mode Control of the Upper Arm of a Shotcrete Robot with Hydraulic Actuator

The upper arm of the shotcrete robot is a closed-chain mechanism. According to the structure, in this paper we have established the dynamic equation of the upper arm using the virtual spring approach and Lagrange formulation along with the constraints. The hydraulic actuator dynamics has also been investigated. Combining them, we obtain the whole dynamic equation of the system. With this as the basis, we further give out the sliding mode control scheme of the upper arm as well as the stability analysis. Preliminary simulation results verified the effectiveness of the dynamic equation and the control method.