An example cold planer system includes a machine frame, a milling rotor disposed in a milling chamber, a first sensor, a second sensor and a control module. The control module comprises a processor and a controller. The processor is configured to receive a first signal indicative of a direction of motion of the machine, and a second signal indicative of whether an object is present in an object detection zone. The processor processes the first signal and the second signal to generate a control signal. The controller is configured to receive the control signal from the processor and to initiate a rotor collision avoidance mode if an object is present in an object detection zone.