Electric drive system for machine and electric drive control system for same

An electric drive system for an electric drive machine comprising:

• an electric drive motor;
• a transmission including a transmission input coupled to the electric drive motor, a transmission output, a first clutch and a second clutch each coupled between the transmission input and the transmission output to operate the transmission, respectively, in a first range transmitting torque from the transmission input via a first gear combination to the transmission output and a second range transmitting torque from the transmission input via a second, different gear combination to the transmission output;
• the first clutch having a first rotatable clutch input portion and a first rotatable clutch output portion, and the second clutch having a second rotatable clutch input portion and a second rotatable clutch output portion, wherein the second rotatable clutch input portion is rotatable at a speed different from a speed of the first rotatable clutch input portion, and wherein speed ratios, between a motor output of the electric drive motor and each respective one of the first rotatable clutch input portion and the second rotatable clutch input portion, are fixed;
• a control system including a sensor structured to monitor a speed parameter of the electric drive machine indicative of a transmission output speed, and an electric drive controller in communication with the sensor and structured to:
• determine suitability of the electric drive machine for shifting the transmission from neutral to a one of the first range or the second range;
• calculate a target transmission input speed, based on the monitored speed parameter and the determined suitability of the electric drive machine for shifting the transmission from neutral to the one of the first range or the second range;
• vary a speed of the electric drive motor based on the target transmission input speed;
• command engaging one of the first clutch or the second clutch corresponding to the one of the first range or the second range, based on the varied speed of the electric drive motor;
• and
• control an actual transmission input speed upon engagement of the one of the first clutch or the second clutch via the varied speed of the electric drive motor while the electric drive motor is supplied with electrical power.

An electric drive system comprising:

• a transmission including a first clutch having a first rotatable clutch input portion and a first rotatable clutch output portion, and a second clutch having a second rotatable clutch input portion and a second rotatable clutch output portion, and wherein the second rotatable clutch input portion is rotatable in the transmission at a speed different from a speed of the first rotatable clutch input portion;
• the transmission further including a transmission input, a transmission output, a first gear combination coupled between the transmission input and the transmission output, and a second, different gear combination coupled between the transmission input and the transmission output, and wherein speed ratios, between the transmission input and each respective one of the first rotatable clutch input portion and the second rotatable clutch input portion, are fixed;
• an electric drive controller structured to:
• receive a first speed signal indicative of a transmission output speed of the transmission in an electric drive machine;
• receive a second speed signal indicative of a transmission input speed of the transmission;
• determine suitability of the electric drive machine for shifting the transmission from neutral to a one of a first range where the first clutch transmits torque from the transmission input to the transmission output via the first gear combination or a second range where the second clutch transmits torque from the transmission input to the transmission output via the second gear combination;
• output a motor control command varying a speed of an electric drive motor coupled to a transmission input of the transmission;
• calculate a transmission input speed error based on a difference between the transmission input speed and a target transmission input speed;
• output a clutch engagement command for engaging one of the first clutch or the second clutch corresponding to the one of the first range or the second range, respectively, at a timing that is based on the transmission input speed error;
• and
• control an actual transmission input speed upon engagement of the one of the first clutch or the second clutch via the varying the speed of the electric drive motor while the electric drive motor is supplied with electrical power.