Adaptive Selection of Transmission Neutralizer Pedal Setpoint

Abstract

An automatic transmission neutralizer system for a machine is disclosed. The system may comprise at least one sensor configured to detect a set of parameters of the machine, a transmission, and a control unit operatively in communication with the at least one sensor and the transmission. The control unit may be configured to: calculate a braking force of the machine and an external force on the machine using the set of parameters detected by the at least one sensor, compare the braking force to the external force, and selectively neutralize the transmission depending on input from the at least one sensor and the comparison of braking force to external force.

What is claimed is: 
     
         1 . An automatic transmission neutralizer system for a machine, comprising:
 at least one sensor configured to detect a set of parameters of the machine;   a transmission; and   a control unit operatively in communication with the at least one sensor and the transmission, the control unit configured to:
 calculate a braking force of the machine and an external force on the machine using the set of parameters detected by the at least one sensor; 
 compare the braking force to the external force; and 
 selectively neutralize the transmission depending on input from the at least one sensor and the comparison of braking force to external force. 
   
     
     
         2 . The system of  claim 1 , wherein the control unit is configured to neutralize the transmission if the braking force is greater than or equal to the external force and a minimum brake pedal position is met. 
     
     
         3 . The system of  claim 2 , wherein the control unit is configured to also neutralize the transmission if a maximum brake pedal position is met. 
     
     
         4 . The system of  claim 3 , wherein the control unit is configured to compare the braking force to a last known calculation for external force if the machine is moving below a threshold speed. 
     
     
         5 . The system of  claim 1 , wherein the control unit calculates the external force on the machine as a function of the braking force, a propulsion force of the machine, a mass and an acceleration of the machine. 
     
     
         6 . The system of  claim 1 , wherein the at least one sensor comprises a brake pedal sensor, and wherein the control unit is configured to calculate the braking force of the machine using input from the brake pedal sensor. 
     
     
         7 . The system of  claim 6 , wherein the brake pedal sensor is configured to detect an angle of depression of a brake pedal of the machine, and wherein the control unit is configured to approximate a brake pressure based on the angle of depression and to calculate the braking force from the brake pressure and a set of known parameters programmed into the control unit. 
     
     
         8 . The system of  claim 1 , wherein the at least one sensor comprises a brake pressure sensor, and wherein the control unit is configured to calculate the braking force of the machine using input from the brake pressure sensor. 
     
     
         9 . The system of  claim 8 , wherein the brake pressure sensor is configured to detect a brake pressure by measuring a hydraulic oil pressure of a brake system of the machine, and wherein the control unit is configured to calculate the braking force from the brake pressure and a set of known parameters programmed into the control unit. 
     
     
         10 . The system of  claim 5 , further comprising a torque converter having an input sensor and an output sensor, and wherein the control unit is configured to calculate the propulsion force using input from the input sensor and output sensor of the torque converter. 
     
     
         11 . The system of  claim 5 , wherein the at least one sensor further comprises a speed sensor configured to detect a speed of a transmission shaft, and wherein the control unit is configured to calculate the speed and acceleration of the machine using input from the speed sensor. 
     
     
         12 . The system of  claim 1 , further comprising a transmission control module, the transmission control module configured to neutralize the transmission based on input from the control unit. 
     
     
         13 . The system of  claim 1 , further comprising an inclinometer, and wherein the control unit is configured to calculate the external force using input from the inclinometer. 
     
     
         14 . A machine comprising:
 a brake pedal having a brake pedal sensor configured to detect an angle of depression of the brake pedal;   a torque converter having an input sensor and an output sensor, the input sensor configured to detect a speed going into the torque converter and the output sensor configured to detect a speed coming out of the torque converter;   a transmission system comprising a transmission, a transmission shaft, and a transmission control module;   a speed sensor configured to detect a speed of the transmission shaft; and   a control unit operatively in communication with the brake pedal sensor, input sensor, output sensor, speed sensor, and transmission control module, the control unit configured to:
 calculate a braking force of the machine using input from the brake pedal sensor; 
 calculate a propulsion force of the machine using input from the input sensor and the output sensor of the torque converter; 
 calculate an acceleration of the machine using input from the speed sensor; 
 calculate an external force on the machine as a function of the braking force, the propulsion force of the machine, a mass and the acceleration of the machine; 
 compare the braking force to the external force; and 
 output a signal to the transmission control module to selectively disengage the transmission based on input from the brake pedal sensor and the comparison of the braking force to the external force. 
   
     
     
         15 . The machine of  claim 14 , wherein the control unit outputs a signal to the transmission control module to disengage the transmission if either a maximum pedal position is met, or a minimum pedal position is met and the braking force is greater than or equal to the external force. 
     
     
         16 . The machine of  claim 15 , wherein the control unit is configured to compare the braking force to a last known calculation for external force if the machine is moving below a threshold speed. 
     
     
         17 . A transmission neutralizer system for a machine, the machine comprising a transmission and a brake pedal having a brake pedal sensor configured to detect a position of the brake pedal, the transmission neutralizer system comprising:
 a transmission control module configured to disengage the transmission; and   a control unit in communication with the transmission control module and the brake pedal sensor, the control unit configured to:
 calculate a braking force and an external force; 
 compare the braking force to the external force; and 
 send a signal to the transmission control module to disengage the transmission based on input from the brake pedal sensor and the comparison of the braking force to the external force. 
   
     
     
         18 . The system of  claim 17 , wherein the machine further comprises an inclinometer, and wherein the control unit is in communication with the inclinometer and is configured to calculate the external force based on input from the inclinometer. 
     
     
         19 . The system of  claim 17 , wherein the control unit is configured to calculate the braking force using input from the brake pedal sensor. 
     
     
         20 . The system of  claim 17 , wherein the machine further comprises a brake pressure sensor configured to detect a brake pressure, and wherein the control unit is configured to calculate the braking force using input from the brake pressure sensor. 
     
     
         21 . The system of  claim 17 , wherein the machine further comprises a speed sensor and a torque converter having an input sensor and an output sensor, and wherein the control unit is in communication with the speed sensor, input sensor and output sensor and is configured to calculate the external force using the braking force calculation and input from the speed sensor, input sensor and output sensor. 
     
     
         22 . A method of neutralizing a transmission of a machine, comprising:
 monitoring a brake pedal position;   calculating a braking force of the machine and an external force on the machine;   comparing the braking force to the external force; and   selectively neutralizing the transmission according to the brake pedal position and comparison of the braking force to the external force.   
     
     
         23 . The method of  claim 22 , further comprising comparing the braking force to a most recent calculation for external force when the machine is moving below a threshold speed.