Drive By Wire Modifications

The Ford Escape Hybrid comes standard with an electronic throttle, electronic power assist steering, and an electronically controlled regenerative braking system. Rather than build actuators for these systems, we decided to interface directly with the vehicle’s existing electronic systems. Our custom electronics were housed in a purpose-built case mounted in the engine compartment.

Two LabJack UE9 data acquisition units interface between the custom circuitry and the vehicle’s computers via TCP/IP, allowing us to control both digital and analog I/O operations on our servers.

Custom circuitry takes the outputs from the LabJacks and shapes the pulses to mimic the vehicle’s throttle position sensor, brake pedal position sensor, and steering torque sensor. The outputs are then connected to the corresponding inputs to the vehicle’s Engine Control Unit (ECU). When the input lines to the ECU are switched to the circuitry outputs, the car is fooled into thinking a person is behind the wheel actuating the pedals and turning the wheel.

The signals from the on-board vehicle speed and ABS wheel sensors are fed in to the LabJacks, providing dead reckoning estimation. Auxiliary circuits control turn signals, brake lights, horn, and audible and visual alarms.

An absolute rotary encoder provided by Posital-Fraba is mounted near the steering column and provides steering position feedback via an ethernet connection.