The optimal trajectory planning problem for trains under operational constraints is considered, which is essential for the success of the real-time operation and the rescheduling process for railway networks. The operational constraints caused by the timetable, real-time operation, or rescheduling often include target points and target window constraints. The approach proposed in this paper can...

We present two schemes for planning the time-optimal trajectory for cooperative multi-manipulator system (CMMS) carrying a common object. We assume that the desired path is given and parameterizable by an arclength variable. Both approaches take into account the dynamics of the manipulators and object. The first approach employs linear programming techniques, and it allows us to obtain the time...

This paper is concerned with the planning of optimal trajectories for vehicle collision avoidance with a Timed Elastic Band (TEB) framework. The avoidance trajectory is represented by a TEB which is optimized with respect to multiple partially conflicting objectives. The resulting trajectory constitutes the optimal compromise between a mere braking and a lane change maneuver that avoids the col...

Recent research in AI Planning is focused on improving the quality of the generated plans. PDDL3 incorporates hard and soft constraints on goals and the plan trajectory. Plan trajectory constraints are conditions that need to be satisfied at various stages of the plan. Soft goals are goals, which need not necessarily be achieved but are desirable. An extension of Constraint Satisfaction Problem...

Direct methods for trajectory optimization are widely used for planning locally optimal trajectories of robotic systems. Most state-of-the-art techniques treat the discontinuous dynamics of contact as discrete modes and restrict the search for a complete path to a specified sequence through these modes. Here we present a novel method for trajectory planning through contact that eliminates the r...

Door passing is the basic capability of an intelligent wheelchair. This paper presents a novel approach to address the door passing issue using Bézier curve based trajectory planning. The planed path consists of two segments: one from corridor to door and the other from door to the goal position. For each segment, an optimal Bézier curve is generated as a reference trajectory for an intelligent...

The first main result of this paper is a novel nonuniform discretization approximation method for the kinodynamic motion-planning problem. The kinodynamic motion-planning problem is to compute a collision-free, time-optimal trajectory for a robot whose accelerations and velocities are bounded. Previous approximation methods are all based on a uniform discretization in the time space. On the con...

This paper is concerned with the problem of finding a time-optimal velocity profile along the predefined path for static formations of mobile robots in order to traverse the path in shortest time and to satisfy, for each mobile robot in the formation, velocity, acceleration, tip over and wheel slip prevention constraints. Time-optimal velocity planning is achieved using so called bang-bang cont...

Designing trajectories for a submerged rigid body motivates this paper. Two approaches are addressed: the time optimal approach and the motion planning approach using concatenation of kinematic motions. We focus on the structure of singular extremals and their relation to the existence of rank-one kinematic reductions; thereby linking the optimization problem to the inherent geometric framework...

This paper focuses on the optimal motion planning problem for cooperative aerial manipulation. We use the rapidly exploring random trees star (RRT*) algorithm that finds feasible paths quickly and optimizes them. For local planning within RRT*, we developed a trajectory planner using Bezier-curve which utilizes the differential flatness property of the aerial manipulator. Time-parameterization ...