Vehicle 2

Vehicle 2 is a robot originally proposed by Braitenberg (1984) as a thought experiment. The robot consisted of two motors and two sensors. The sensors were on either side of the front of the robot, while the motors were on either side of the rear of the robot. Each sensor was attached to a motor, and the speed of the motor depended upon the value being delivered by the sensor. For instance, if the sensor was a light detector then the brighter the light that was detected, the faster would run the motor. If both motors were running at the same speed, then the robot would move straight ahead. However, if one motor was running faster than the other, then the robot would turn in the direction of the slower motor.

Braitenberg (1984) argued that if the sensors were connected to the motors on the same side of the robot, then the robot would avoid sources of whatever quantity was being measured by the sensors. In contrast, if the sensors were connected to the motors on the opposite side of the robot, then the robot would be attracted to sources of whatever quantity was being detected. Braitenberg used this thought experiment to demonstrate that a simple device could generate complicated behavior if it was situated within a complex environment, a point also made in the famous parable of the ant (Simon, 1969). Dawson, Dupuis, and Wilson (2010) demonstrated that the embodiment of a Vehicle 2 was also critical. They constructed a version of this robot from Lego components and demonstrated that if the sensors had overlapping receptive fields, then the machine would avoid light sources that were far away but would attack light sources that were close to the robot.

References: