Electrohydraulic control system for a vehicle

Abstract

An electronic control system and data-logging system for a snow removal vehicle. The vehicle includes hydraulically actuated tools, the control of which can be through a dual axis controller such as a joystick. Electrical communication among components in the system is provided by a power line carrier protocol (PLC).

1 . An apparatus for controlling a snowplow of a vehicle, comprising:
 a hydraulically actuatable snowplow mounted to the vehicle and movable over a range of positions;   a hydraulic actuator for moving said snowplow over the range at a rate of movement;   an electrohydraulic interface unit which receives an actuation signal and provides hydraulic fluid to said actuator in response thereto;   an electrical interface unit which receives a command signal and produces said actuation signal in response thereto;   a joystick movable in a direction over a range of positions and providing a first data signal which is proportional to the position of said joystick; and   a keypad having first and second manual switches, said first switch providing a fixed predetermined second data signal when switched, said second switch providing a fixed predetermined third data signal when switched;   wherein said first data signal, said second data signal, and said third data signal correspond to a desired rate of movement of said snowplow, and one of said first data signal, said second data signal, or said third data signal correspond to said command signal.   
   
   
       2 . The apparatus of  claim 1  wherein said keypad produces said actuation signal in response to one or the other of said joystick or said keypad 
   
   
       3 . The apparatus of  claim 1  which further comprises a hydraulically actuatable dump body mounted to the vehicle and movable over a second range of positions;
 a second hydraulic actuator for moving said dump body over the second range at a rate of movement;   said electrohydraulic interface unit receiving a dump signal and providing hydraulic fluid to said second actuation in response thereto; and   a selection switch providing a selection signal to said electrical interface unit, said electrical interface unit using the state of said selection switch to determine if said first data signal corresponds to movement of said dump body or movement of said snowplow.   
   
   
       4 . The apparatus of  claim 3  wherein if said joystick remains centered for a more than a predetermined period time, the electrical interface unit automatically correspond said first signal to movement of said snowplow. 
   
   
       5 . The apparatus of  claim 1  wherein said electrohydraulic interface unit includes at least one proportional solenoid and at least one spool valve, said solenoid applying a force to said valve which is proportional to said actuation signal. 
   
   
       6 . The apparatus of  claim 1  wherein the vehicle includes a DC electrical system, said actuation signal is at a frequency, and said electrical interface unit places said actuation signal on said DC electrical system. 
   
   
       7 . The apparatus of  claim 1  which further includes a third switch adjustable by the vehicle operator and providing an output variable between high and low limits, wherein the output of said third switch establishes said second data signal. 
   
   
       8 . An apparatus for controlling the snow removal functions of a vehicle, comprising:
 a vehicle including a hydraulically actuatable snowplow and a second actuatable tool;   an electrohydraulic interface unit which receives an actuation signal and provides hydraulic fluid to said snowplow or said tool in response thereto;   an electrical interface unit which receives a command signal and produces said actuation signal in response thereto, said interface unit receiving an identification signal and responsive to select one of said snowplow or said tool for actuation in response thereto; and   a joystick movable in each of two directions over a range of positions and providing said command signal which is proportional to the position of said joystick, said joystick including a first switch and a second switch;   wherein the states of said first switch and second switch provides said identification signal   
   
   
       9 . The apparatus of  claim 8  wherein said command signal is proportional to the rate of movement of said snowplow or said tool. 
   
   
       10 . The apparatus of  claim 8  wherein said electrical interface unit responds to said identification signal only if said joystick is generally centered. 
   
   
       11 . The apparatus of  claim 8  which further comprises a hydraulically actuatable dump body and a third switch, said electrohydraulic interface unit providing hydraulic fluid to dump body, said electrical interface unit selecting one of said snowplow, said tool, or said dump body for actuation, and wherein the states of said first switch, second switch, and said third switch provides said identification signal. 
   
   
       12 . The apparatus of  claim 8  wherein said joystick includes a deadman switch providing a signal to said electrical interface unit corresponding to the presence of a user of the vehicle, said electrical interface unit providing said actuation signal only if the user is present. 
   
   
       13 . The apparatus of  claim 8  wherein said joystick includes dual redundant sensors for providing said command signal. 
   
   
       14 . The apparatus of  claim 8  wherein said joystick is centerable in each of the two directions and said electrical interface unit is programmable to apply a deadband region to each direction. 
   
   
       15 . A method for controlling the snowplow of a truck, comprising:
 providing a truck having an actuatable snowplow actuatable in each of two directions at a variable rate of movement and a two axis controller, wherein the controller is moveable in each axis over a range of positions, the snowplow is actuatable in each direction over a range of rates of movement, and the range of positions corresponds to the range of rates;   moving the snowplow in one direction at a predetermined rate in response to movement of the controller in one axis to a predetermined position; and   moving the snowplow in the other direction at a predetermined rate in response to movement of the controller in the other axis to a predetermined position.   
   
   
       16 . The method of  claim 15  further comprising providing the truck with a dump body actuatable in a direction over a range of rates of dumping movement, and the range of positions is capable of corresponding to the range of rates of dumping movement;
 selecting the range of positions to correspond to the range of rates of dumping movements and preventing the range of positions from corresponding to the range of rates of snowplow movement.   
   
   
       17 . A system for electronically logging the snow and ice removal functions of a vehicle, comprising:
 a vehicle having an electrical power system and including a snowplow hydraulically actuatable to a plurality of positions and a system for distributing a granular product on a roadway within a range of distribution rates;   a first sensor providing a first signal corresponding to the position of the snowplow, a second sensor providing a second signal corresponding to the distribution rate of the product, a third sensor providing a third signal corresponding to the position of the vehicle, and a clock providing a time signal; and   electronic data capturing and computational module that receives the first signal, second signal, third signal, and time signal, the first signal and second signal being transmitted from the corresponding said sensor to said module by communication over the power system, said module using the second signal, third signal, and time signal to compute a product output rate in terms of weight of product distributed per unit distance.   
   
   
       18 . The system of  claim 17  which further comprises an automatic vehicle locating system, wherein the computed data is provided to the AVL system. 
   
   
       19 . The system of  claim 17  which further comprises a repeatedly removable non-volatile memory unit, wherein the computed data is provided to the unit.