Patent ID: 6856035
Filing Date: 2005-02-15
Classification: B60K,B60L,B60W,B60Y,Y02T

Abstract:
1. A control method for a drive system utilizing a first motor with a first motor current, a first motor speed, and a first motor speed control signal and a second motor with a second motor current, a second motor speed, and a second motor speed control signal, wherein the control method is used to electrically simulate the characteristics of a mechanical differential, comprising: detecting a drop in motor current associated with a loss of traction; matching the first motor current into the first motor with a second motor current into the second motor; repeating the matching until the first current and the second current are substantially equal; aligning the average speed of the first motor and the second motor with a speed set-point; repeating the aligning until the average of the two motor speeds are substantially equal to the speed set-point; measuring the current into the fastest motor; measuring the current into the slowest motor; comparing the currents of the fastest motor and the slowest motor; returning to the matching step if the fastest motor current is lower than the slowest motor current; and adjusting the motor speed, incrementing the current to the slowest motor, and returning to aligning only if the fastest motor current is higher than the slowest motor current.