An implementation of redundancy resolution and stability monitoring for a material handling vehicle

The ATLAS (All-Terrain Lifter Articulated System) vehicle is a prototype for the next-generation Army material handling vehicle. The vehicle features a redundant manipulator with five degrees of freedom in a plane and a forklift end-effector. The original control system only allowed single joint motion control via a set of joysticks in the cab. A new controller was developed to automatically coordinate all joints in the system and allow the operator to directly control the motions of the end-effector with constant orientation via a single joystick. In addition, a stability monitor was developed that prevents the operator from tipping over the vehicle when manipulating heavy loads of uncertain weight, or warns him of approaching stability limits when driving. Finally, a load-compensation function was developed that automatically tips back the fork tines when a heavy load is lifted