Dynamic analysis and control of ground vehicle-mounted gun turret incorporating non-smooth dynamics

Abstract

The present study investigates the design of controllers to stabilize an armed turret mounted on a moving platform on uneven ground. Including kinematic joints and contact constraints resulting from interactions with its surroundings, the turret-vehicle system is described as a constrained multibody system. A Linear Complementarity Problem (LCP) method was used to represent the non-smooth dynamics, such as impacts and contacts with friction forces. Essential factors, including the suspension of the vehicle, the recoil forces from shooting, and the control inputs used to maintain turret stability, are also incorporated in the model. Using an external ballistic model, the path of the bullet from the time it leaves the barrel until it reaches its target was modeled and used to identify the exact elevation angle to hit the target and also to calculate the hit probability after many shots. We investigated many control techniques including Proportional-Integral-Derivative (PID), Linear Quadratic Regulator (LQR), and Sliding Mode Control (SMC) to guarantee stability even against disturbances such as firing and operational conditions. By comparing different techniques, it was found which one is more efficient in reducing disturbances and maintaining turret stability. Simulations across multiple vehicle speeds and terrain scenarios consistently showed that SMC achieved the best stabilization and hit probability performance compared to PID and LQR, demonstrating its robustness under varying operating conditions. Numerical simulations demonstrate that a more realistic and accurate depiction of the behavior of the system arises from adopting a non-smooth dynamics model, hence guiding the choice of stabilization technique and its parameters.