Automatic train stop control system
A method controls a movement of a train to a stop at a stopping position between a first position and a second position. The method determines constraints of a velocity of the train with respect to a position of the train forming a feasible area for a state of the train during the movement, such that an upper curve bounding the feasible area has a zero velocity only at the second position, and a lower curve bounding the feasible region has a zero velocity only at the first position. Next, the method controls the movement of the train subject to the constraints.
1. A system for controlling of a movement of a train to a stop at a stopping position between a first position and a second position, comprising:
a constraint generating unit for determining constraints of a velocity of the train with respect to a position of the train forming a feasible area for a state of the train during the movement, such that an upper curve bounding the feasible area has a zero velocity only at the second position, and a lower curve bounding the feasible region has a zero velocity only at the first position, wherein the upper curve is a first line with a first slope, and the lower curve is a second line with a second slope and the first slope is greater than the second slope; and
a controller for controlling the movement of the train subject to the constraints.
2. The system of claim 1 , further comprising:
a control invariant subset generating unit for determining a control invariant subset of the feasible region, wherein for each state within the control invariant subset there is at least one control action maintaining the state of the train within the control invariant subset, wherein the controller controls the movement of the train by selecting a control action maintaining the state of the train within the control invariant subset of the feasible region.
3. The system of claim 2 , wherein the control invariant subset generating unit determines the control invariant subset using a backward-reachable region computation starting from the feasible region.
4. The system of claim 1 , wherein the feasible area includes a current position of the train and a current velocity of the train, and wherein the first and the second positions define a stopping range for the train, such that the first position is closer to the current position of the train than the second position.
5. The system of claim 1 , wherein the constraints are determined without having a predetermined run-curve leading the train from the current position to the stopping position.
6. The system of claim 1 , wherein the upper curve is a first line with a first slope, and the lower curve is a second line with a second slope and the first slope is greater than the second slope.
7. The system of claim 1 , wherein the first slope is selected based on a minimal stopping time, and the second slope is selected based on a maximal stopping time.