Method and system for vehicle traction

Abstract

Various methods and systems are provided for automatically applying tractive material during operation of a vehicle. In one embodiment, the application of tractive material for a vehicle is adjusted based on calculated and expected tractive effort for each powered truck, axle, or wheel of the vehicle. In this way, tractive material application is controlled on a per truck, axle, or wheel basis in order to reduce excessive use of tractive material during operation of the vehicle.

1 . A method for a vehicle, comprising:
 controlling application of tractive material for each of one or more wheel, axle, or truck of the vehicle based on respective individual actual tractive effort of each of the one or more wheel, axle, or truck.   
     
     
         2 . The method of  claim 1 , wherein controlling application of tractive material includes delivering tractive material responsive to an actual tractive effort for a given wheel, axle, or truck being less than an expected tractive effort of the given wheel, axle, or truck. 
     
     
         3 . The method of  claim 1 , wherein the actual tractive effort for the given truck is based at least in part on one or more of stator current, applied voltage, air gap flux, and speed feedback from one or more traction motors powering one or more axles of the given truck. 
     
     
         4 . The method of  claim 1 , wherein controlling application of tractive material for each of the one or more wheel, axle, or truck includes controlling application of tractive material individually for a lead wheel, axle, or truck and a rear wheel, axle, or truck. 
     
     
         5 . The method of  claim 4 , wherein controlling application of tractive material individually for the lead wheel, axle, or truck and the rear wheel, axle, or truck includes responding to a sensed lead wheel, axle, or truck tractive effort being less than an expected lead wheel, axle, or truck tractive effort. 
     
     
         6 . The method of  claim 1 , further comprising delivering tractive material to a wheel, axle, or truck in response to a signal indicating slipping of that specific wheel, axle, or truck. 
     
     
         7 . The method of  claim 2 , further comprising delivering a stream of compressed air to a portion of a route in advance of an interface of a wheel with the route, and not disturbing or removing tractive material from the route via the stream of compressed air. 
     
     
         8 . The method of  claim 1 , further comprising derating a lead truck traction motor, a rear truck traction motor, or both a lead and rear truck motor based at least in part on an expected lead truck tractive effort. 
     
     
         9 . The method of  claim 2 , wherein delivering tractive material includes delivering compressed air along with delivering tractive material. 
     
     
         10 . A controller for a vehicle having one or more of a wheel, axle, or truck, comprising:
 one or more processors configured to initiate an application of tractive material for the one or more of the wheel, axle, or truck of the vehicle based on respective individual actual tractive effort of the one or more of the wheel, axle, or truck.   
     
     
         11 . The controller of  claim 10 , wherein the controller is configured to apply tractive material responsive to an actual tractive effort for a given wheel, axle, or truck being less than an expected tractive effort of the given wheel, axle, or truck. 
     
     
         12 . The controller of  claim 11 , wherein the actual tractive effort for the given truck is based at least in part on one or more of stator current, applied voltage, air gap flux, and speed feedback from one or more traction motors powering one or more axles of the given truck. 
     
     
         13 . The controller of  claim 10 , wherein the vehicle further includes a tractive material reservoir coupled to a plurality of nozzles, each nozzle positioned to deliver the tractive material to the one or more of the wheel, axle, or truck. 
     
     
         14 . The controller of  claim 10 , wherein the one or more processors are configured to initiate the application of the tractive material for a first wheel of the vehicle independent of application of the tractive material for a second wheel of the vehicle, the first and second wheels positioned on a same axle. 
     
     
         15 . The controller of  claim 10 , wherein the one or more processors are configured to initiate the application of the tractive material for a first truck of the vehicle independent of application of the tractive material for a second truck of the vehicle. 
     
     
         16 . The controller of  claim 10 , wherein the vehicle further includes a compressed air source configured to deliver a stream of compressed air to a portion of a route in advance of an interface of a wheel with the route, and not disturb or remove tractive material from the route via the stream of compressed air. 
     
     
         17 . A vehicle comprising the controller of  claim 10 . 
     
     
         18 . A vehicle system comprising:
 a lead truck including a lead truck drive system including one or more lead truck traction motors coupled in driving relationship to a plurality of wheels of the lead truck, the one or more traction motors configured to provide motive power for the lead truck;   a rear truck including a rear truck drive system including one or more rear truck traction motors coupled in driving relationship to a plurality of wheels of the rear truck, the one or more traction motors configured to provide motive power for the rear truck;   a tractive material application system including a common reservoir for tractive material, the common reservoir fluidly coupled to one or more lead truck nozzles and one or more rear truck nozzles, the one or more lead truck nozzles and the one or more rear truck nozzles delivering tractive material ahead of the plurality of lead truck wheels and plurality of rear truck wheels respectively;   a controller configured with instructions in non-transitory memory that when executed cause the controller to:
 responsive to the lead truck slipping and a number of lead truck axles slipping greater than a threshold number, deliver tractive material via the one or more lead truck nozzles; otherwise operate the vehicle without delivering tractive material via the one or more lead truck nozzles; and responsive to the rear truck slipping and a number of rear truck axles slipping greater than the threshold number, deliver tractive material via the one or more rear truck nozzles; otherwise operate the vehicle without delivering tractive material via the one or more rear truck nozzles. 
   
     
     
         19 . The vehicle system of  claim 18 , wherein the lead truck slipping is based on an actual tractive effort of the lead truck being less than an expected lead truck tractive effort, the expected lead truck tractive effort based on an expected vehicle tractive effort; and the rear truck slipping based on an actual tractive effort of the rear truck being less than an expected rear truck tractive effort, the expected rear truck tractive effort based on the actual lead truck tractive effort and the expected vehicle tractive effort. 
     
     
         20 . The vehicle system of  claim 19 , wherein the controller includes further instructions that when executed causes the controller to: adjust the expected lead truck tractive effort based on one or more deration conditions of the one or more lead truck traction motors; and adjust the expected rear truck tractive effort based on one or more deration conditions of the one or more rear truck traction motors.