Wobble compensation of an encoder speed signal for an electric motor

A vehicle comprising:

• an electric traction motor;
• a transmission which is selectively powered by the traction motor to thereby propel the vehicle in an electric-vehicle (EV) operating mode;
• a speed encoder configured to measure a rotational speed of the traction motor, and to transmit the measured rotational speed as an encoder signal;
• and
• a control system configured to compensate for angular wobble in the encoder signal, the control system including a hybrid control processor (HCP) and a motor control processor (MCP), wherein the HCP coordinates, at a first hierarchical level, inputs to the transmission based on the current hybrid operating strategy, and, and wherein the MCP controls an operation of the traction motor, at a second hierarchical level that is lower than that of the first hierarchical level, using a set of input signals, wherein the control system is further configured to:
• receive, via the HCP, the encoder signal directly from the speed encoder;
• determine a set of wobble characteristics of the encoder signal only when the measured rotational speed is below a threshold motor speed;
• calculate a wobble-compensated speed value, solely via the HCP, using the set of wobble characteristics;
• transmit the wobble-compensated speed value to the MCP;
• and
• use the wobble-compensated speed value as at least part of the input signals when controlling the motor via the MCP.