Navigation control for an exploration rover with microwave Doppler sensors (Fabrication of second prototype rover and experiments)

In this study, fist, we conducted a study on the navigation control for a rover using microwave Doppler sensors. Microwave Doppler sensors commonly used in automatic-door systems have been used in a rover navigation system. A collimated microwave beam with an angular width of ±3° at a frequency of 24 GHz was emitted from a sensor (A) on a dish antenna 30 cm in diameter. Another sensor (B), which works as a detector, was installed on the rover. The rover was programmed to make a right turn when the microwave signal was above a specified level and to make a left turn when the signal was than that level. The rover started from a point 70 m away and approached to within 1.5 m of sensor A. This navigation method is useful when GPS is not usable. Second, we proposed a method to avoid irregular surfaces on a ground because the prototype rover we have previously developed could not be navigated owing to the cut of the microwave beam by large irregularity of ground surfaces. In this study, second prototype rover with a function of avoiding the irregular ground surfaces was fabricated and we confirmed the effectiveness of the proposed method through some experiments.