The inventive subject matter described herein relates generally to powered vehicle systems. Although one or more embodiments are described and shown in terms of rail vehicle systems, not all embodiments are so limited. For example, one or more embodiments may relate to other types of vehicles, such as automobiles, marine vessels, other off-highway vehicles, and the like.
Known powered rail vehicle systems include one or more powered units and, in certain cases, one or more non-powered units. The powered units supply tractive force to propel the powered units and non-powered units. The non-powered units hold or store goods and/or passengers. (“Non-powered” unit generally encompasses any vehicle without an on-board source of motive power.) For example, some known powered rail vehicle systems include a rail vehicle system (e.g., train) having powered locomotives and non-powered cars for conveying goods and/or passengers along a track. Some known powered vehicle systems include several powered units. For example, the systems may include a lead powered unit, such as a lead locomotive, and one or more remote or trailing powered units, such as trailing locomotives, that are located behind and (directly or indirectly) coupled with the lead powered unit. The lead and remote powered units supply tractive force to propel the vehicle system along a route, such as a track.
The tractive force required to convey the powered units and non-powered units along the route may vary during a trip. For example, due to various parameters that change during a trip, the tractive force that is necessary to move the vehicle system along the route may vary. These changing parameters may include the curvature and/or grade of the route, speed limits and/or requirements of the vehicle system, and the like. As these parameters change during a trip, the total tractive effort, or force, that is required to propel the vehicle system along the track also changes.
While the required tractive effort may change during a trip, the operators of these powered rail vehicle systems do not have the ability to remotely turn the electrical power systems of remote powered units on or off during the trip. For example, an operator in a lead locomotive does not have the ability to remotely turn one or more of the trailing locomotives' electrical power on or off, if the tractive effort required to propel the train changes during a segment of the trip while the rail vehicle system is moving. Instead, the operator may only have the ability to locally turn on or off the remote powered units by manually boarding each such unit of the rail vehicle system.
Some known powered rail vehicle systems provide an operator in a lead locomotive with the ability to change the throttle of trailing locomotives (referred to as distributed power operations). But, these known systems, do not provide the operator with the ability to turn the trailing locomotives off. Instead, the operator must turn down the throttle of the trailing locomotives that he or she wants to turn off and wait for an auto engine start/stop (AESS) device in the trailing locomotives to turn the locomotives off. Some known AESS devices do not turn the trailing locomotives off until one or more engine- or motor-related parameters are within a predetermined range. For example, some known AESS devices may not shut off the engine of a trailing locomotive until the temperature of the engine decreases to a predetermined threshold. If the time period between the operator turning down the throttle of the trailing locomotives and the temperature of the engines decreasing to the predetermined threshold is significant, then the amount of fuel that is unnecessarily consumed by the trailing locomotives can be significant. Known powered vehicle systems may include one or more powered units (e.g., locomotives) and one or more non-powered units (e.g., freight cars or other rail cars). The powered units supply tractive force to propel the powered units and non-powered units. The non-powered units hold or store goods and/or passengers, and are not capable of self-propulsion. For example, some known powered vehicle systems have locomotives and rail cars for conveying goods and/or passengers along a track. Some known powered rail vehicle systems include several powered units. For example, the systems may include a lead powered unit, such as a lead locomotive, and one or more remote powered units, such as trailing locomotives, that are located behind and coupled with the lead powered unit. The lead and remote powered units supply tractive force to propel the system along the track.
The remote powered units may be organized in motive power groups referred to as consists. (Generally, a consist is a group of vehicles that are mechanically linked together to travel along a route. As part of a train or other larger consist, a motive power group of remote powered units would be considered a sub-consist or remote consist.) The lead powered unit can control the tractive efforts of the remote powered units in consist. The remote powered units in consist can consume fuel during a trip of the vehicle system. To reduce the amount of fuel consumed by the remote vehicles, one or more operational modes of the consist may be changed during operation.
Changing operational modes of the consist, however, may result in fluctuations of various components or systems of the consist. For example, changing operational modes may cause voltage fluctuations in electrical circuits of the consist, fluctuations in hydraulic pressures of the consist, or the like. These fluctuations may be incompatible with certain on-board control and/or communication systems of the consist. As a result, the on-board systems may be unable to operate due to the fluctuations.
Additionally, some known rail vehicle systems may include more horsepower that is necessary to enable the vehicle systems to travel over a route to a destination location. For example, the operators that combine several locomotives into a consist of a train may add more locomotives to the train than is necessary. The total horsepower provided by the locomotives may exceed what is needed to allow the train to travel to a destination. The additional locomotives cause additional consumption of fuel and/or generation of additional emissions, which is generally undesirable.
It may be desirable to have a vehicle control system and method that differs in function from those systems that are currently available.