Control system for an electrically propelled traction vehicle

A control system for an electrical propulsion system for a wheeled vehicle adapted to haul a payload, the vehicle being equipped with a plurality of adjustable speed electric traction motors mechanically coupled in driving relation to separate wheels on the vehicle, the vehicle having an internal combustion engine and a foot pedal input for demanding horsepower from the internal combustion engine, the vehicle further having an electric generating means operatively connected to the engine and to the traction motors and providing electric power at its output for energizing the traction motors, the electric generating means being of the type which can vary the voltage and current of the electric power provided at its output responsive to control signals being applied thereto and having a first predetermined operating temperature of a component thereof that correlates to a rating at which continuous operation can occur without substantial risk of damage thereto, and a maximum predetermined operating temperature higher than the first predetermined operating temperature of the component during which continuous operation would create a substantial risk of damage to the electric generating means, said control system comprising:

• processing means including memory means for controlling the operation of the internal combustion engine and the electric generating means;
• means for measuring the ambient temperature of the environment in which the vehicle is operating and generating a signal indicative of said measured ambient temperature and applying the same to said processing means;
• means for measuring the output voltage of the electric generating means and generating a signal indicative of said measured output voltage and applying the same to said processing means;
• means for measuring the output current of the electric generating means and generating a signal indicative of said measured output current and applying the same to said processing means;
• fuel enhancement means for conserving fuel usage during periods of vehicle coast and electric brake;
• said processing means being adapted to generate control signals, including a retard pedal depression signal from the fuel enhancement means for conserving fuel usage during the periods of vehicle coast and electric brake by requiring minimum engine rpm to maintain proper cooling of vehicle equipment, and also to apply the control signals to the electric generating means to increase the electric power provided at its output above the continuous rating and to generate and apply control signals to the electric generating means to return the same to the continuous rating responsive to a calculated simulated temperature reaching the maximum predetermined operating temperature of the component of the electric generating means.

A control system for an electrical propulsion system for a wheeled vehicle adapted to haul a payload, the vehicle being equipped with a plurality of adjustable speed electric traction motors mechanically coupled in driving relation to separate wheels on the vehicle, the vehicle having an internal combustion engine and a foot pedal input operable by an operator for demanding horsepower from the internal combustion engine, the vehicle further having an electric generating means operatively connected to the engine and to the traction motors and providing electric power at its output for energizing the traction motors, the electric generating means being of the type which can vary the voltage and current of the electric power provided at its output responsive to control signals being applied thereto and having a first predetermined operating temperature of a component thereof that correlates to a rating at which continuous operation can occur without substantial risk of damage thereto, and a maximum predetermined operating temperature higher than the first predetermined operating temperature of the component during which continuous operation would create a substantial risk of damage to the electric generating means, said control system comprising:

• processing means including memory means for controlling the operation of the internal combustion engine and the electric generating means;
• means for measuring the ambient temperature of the environment in which the vehicle is operating and generating a signal indicative of said measured ambient temperature and applying the same to said processing means;
• means for measuring the output voltage of the electric generating means and generating a signal indicative of said measured output voltage and applying the same to said processing means;
• means for measuring the output current of the electric generating means and generating a signal indicative of said measured output current and applying the same to said processing means;
• fuel enhancement means for determining the horsepower demand from the foot pedal input and generating a horsepower request signal to the processing means indicative of a rpm necessary to provide required power in a propel mode;
• said processing means being adapted to generate control signals, including an engine rpm signal based on the horsepower request signal from the fuel enhancement means and apply the same to the vehicle engine to conserve fuel usage, and further including an engine rpm signal from the fuel enhancement means for conserving fuel usage during periods of vehicle coast and electric brake by requiring minimum engine rpm to maintain proper cooling of vehicle equipment, and also to apply the control signals to the electric generating means to increase the electric power provided at its output above the continuous rating and to generate and apply control signals to the electric generating means to return the same to the continuous rating responsive to a calculated simulated temperature reaching the maximum predetermined operating temperature of the component of the electric generating means.