Method for Determining Run-Curves for Vehicles Based on Travel Time

• US 20140005876A1
• Filed: 06/29/2012
• Published: 01/02/2014
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Xu, Jingyang, Nikovski, Daniel
• Granted Patent: US 8,838,304 B2
• Time in Patent Office: Days
• US Class Current: 701/29.1
• CPC Class Codes: B61L 15/0058 On-board optimisation of vehicle or vehicle train operation

Abstract

A method reduces the computation time for determining optimal run-curves for a specific travel time of a vehicle along a route between two locations. The computation is partitioned between pre-processing and real-time steps. A set of weights μ are generated, and run-curves for the weights are obtained and stored during the pre-processing. State transition matrices can also be determined and stored during the pre-processing. During real-time, a specific travel time is obtained. The travel time is used to interpolate the weight μ for the specific travel time from the stored weights. The memory can be updated for each solution for a specific travel time to dramatically reduce the time to optimize the run-curves.

Claims

1. A method for determining an optimal run-curve for a vehicle under a constraint of travel time T along a route between two locations while minimizing consumption of energy, comprising off-line pre-processing and real-time processing, wherein the off-line preprocessing comprises the steps of:

generating a set of pairs of weights and corresponding travel times, wherein, for each weight and each travel time in each pair, the weight minimizes the energy consumed by the vehicle as a function of the travel time;

storing processing, the pairs of weights and the corresponding travel times in a memory; and

wherein the real-time processing comprises the steps of;

receiving a specific travel time;

determining the weight for the specific travel time using the set of weights; and

generating the run-curve for the vehicle based on the weight for the specific travel time.

2. The method of claim 1, further comprising:

storing, during the off-line pre-processing, a state transition matrix for each weight and travel time in the memory to enable an approximate dynamic programming method to be applied for the real-time steps.

3. The method of claim 1, wherein the weight for the specific travel time arc obtained by interpolating the stored weights and travel times.

4. The method of claim 1, further comprising:

updating the memory with data obtained during the real-time processing.

5. The method of claim 1, wherein the specific travel time is only available a relatively small number of seconds before departure of the vehicle in real-time.

6. The method of claim 1, wherein the specific travel time is received after departure of the vehicle.

7. The method of claim 1, wherein the off-line pre-processing steps are performed once for each vehicle and route profiles.

8. The method of claim 1, wherein the vehicle is a train.

9. The method of claim 1, wherein the train is part of a subway system.

10. The method of claim 1, wherein the travel time T is f(μ

), wherein μ

is the weight.

11. The method of claim 1, wherein the interpolating is according to

μ

′

=f<sup>−

1</sup>(T′

),

wherein T′

, is the specific travel time, and μ

′

is the corresponding weight.