A Brake Traction Control System (BTCS) for an off-road type vehicle includes a 2WD/4WD switch adapted to switch a drive mode of the vehicle between a two-wheel drive mode (2WD) and a four-wheel drive mode (4WD). The switch is configured to be manually activated by an associated vehicle operator. A control unit is in signal communication with the 2WD/4WD switch. The control unit is operable to activate the BTCS only if the drive mode is switched to the four-wheel drive mode and predetermined vehicle operating conditions relating to engine throttle position or opening and wheel speed are subsequently satisfied.

A control device may be configured for responding to failure for ensuring the stability of a vehicle by switching from a two-wheel-drive mode to a four-wheel-drive mode when detecting failure of the brake system in a two-wheel-drive mode.

Fuzzy-logic based traction control for electric vehicles is provided. The system detects a wheel slip ratio for each wheel. The system receives an input torque command. The system determines a slip error for each wheel based on the wheel slip ratio for each wheel and a target wheel slip ratio. The system, using the fuzzy-logic based control selection technique, selects a traction control technique from one of a least-quadratic-regulator, a sliding mode controller, a loop-shaping based controller, or a model predictive controller. The system generates a compensation torque value for each wheel. The system generates the compensation torque value based on the traction control technique selected via the fuzzy-logic based control selection technique and the slip error for each wheel. The system transmits commands to actuate drive units of the vehicles based on the compensation torque value.

A control device may be configured for responding to failure for ensuring the stability of a vehicle by switching from a two-wheel-drive mode to a four-wheel-drive mode when detecting failure of the brake system in a two-wheel-drive mode.

Provided is a control apparatus, a control method, and a control system for an electric vehicle that can prevent or reduce an unnecessary torque fluctuation on a wheel not targeted for slip control. A control apparatus for an electric vehicle limits a torque to be output to a non-target wheel according to a torque output to a target wheel after target wheel slip control is started, and updates a limit value of the torque to be output to the non-target wheel when a fluctuation range of the torque output to the target wheel falls within a predetermined range during the limitation.

A method for updating a vehicle reference speed for a vehicle is disclosed. The method includes increasing brake pressure to at least one wheel of the plurality of wheels and determining, via an electronic control unit, that a first wheel speed of the at least one wheel is less than a second wheel speed of another wheel of the plurality of wheels. The method also includes estimating the vehicle reference speed of the vehicle based upon the first wheel speed of the at least one wheel.

Fuzzy-logic based traction control for electric vehicles is provided. The system detects a wheel slip ratio for each wheel. The system receives an input torque command. The system determines a slip error for each wheel based on the wheel slip ratio for each wheel and a target wheel slip ratio. The system, using the fuzzy-logic based control selection technique, selects a traction control technique from one of a least-quadratic-regulator, a sliding mode controller, a loop-shaping based controller, or a model predictive controller. The system generates a compensation torque value for each wheel. The system generates the compensation torque value based on the traction control technique selected via the fuzzy-logic based control selection technique and the slip error for each wheel. The system transmits commands to actuate drive units of the vehicles based on the compensation torque value.

In a method for drive optimization in a motor vehicle including at least two drivable wheels at a vehicle axle having individually settable drive torque, to increase the propelling force, the drive torque at at least one wheel is increased in such a way that an increased longitudinal slip of at least 20% results at the wheel.

A vehicle includes front suspension assemblies; rear suspension assemblies; a left driven wheel and a right driven wheel with first left and right brake assemblies; a left wheel and a right wheel with second left and right brake assemblies; an anti-lock braking system (ABS) module; a drive mode coupler connected between the transmission and the left and right wheels for changing between a 24 and a 44 drive configuration; and a drive mode switch for controlling the drive mode coupler, the ABS module selectively performing brake traction control of at least one wheel based on the position of the drive mode switch. A method for controlling traction of the vehicle includes sensing the drive mode switch position and when the drive mode changes from a 24 position to a 44 position, causing the ABS module to perform brake traction control on at least one wheel.

In a method for drive optimization in a motor vehicle including at least two drivable wheels at a vehicle axle having individually settable drive torque, to increase the propelling force, the drive torque at at least one wheel is increased in such a way that an increased longitudinal slip of at least 20% results at the wheel.