Control system for a motor vehicle and method

A vehicle comprising:

• a plurality of wheels;
• a powertrain to drive the plurality of wheels;
• a braking system to brake the plurality of wheels;
• and
• a control system, configured to operate in one of a first mode and a second mode in dependence at least in part on an amount of slip experienced by at least one of the wheels,
• wherein, in the first mode, the control system is configured to cause the powertrain to generate a predetermined amount of drive torque,
• wherein, in the second mode, the control system is configured to cause the powertrain to rotate at a predetermined speed by controlling commutation of a motor of the powertrain so as to enforce a desired speed on rotation of a magnetic field of the motor, and
• wherein the control system is configured to operate in the first mode if the amount of slip experienced by at least one of the wheels is below a predetermined slip amount and to operate in the second mode if the amount of slip experienced by at least one of the wheels exceeds the predetermined slip amount.

A method of controlling an electric propulsion motor to drive at least one wheel of a vehicle, the method comprising:

• causing a control system to operate in one of a first mode and a second mode in dependence at least in part on an amount of slip experienced by the at least one wheel,
• whereby in the first mode the method comprises causing the electric propulsion motor to generate a predetermined amount of drive torque, and
• in the second mode the method comprises causing the electric propulsion motor to rotate at a predetermined speed by controlling commutation of the electric propulsion motor so as to enforce a desired speed on a rotation of a magnetic field of the electric propulsion motor,
• whereby the control system is configured to operate in the first mode if an amount of wheel slip is below a predetermined slip amount and to operate in the second mode if an amount of wheel slip exceeds the predetermined slip amount.