Landing with Time-to-Contact and Ventral Optic Flow Estimates

摘要: Many recent studies on autonomous spacecraft landing use computer vision methods to improve the accuracy of state estimates used for landing. Typically, these integrate module with other exteroceptive sensors such as laser or radar altimeters. This is a sensible approach main system large spacecraft. However, backup emergency much smaller spacecrafts, solution entirely based and proprioceptive (e.g. gyros) could lead significant mass savings. Small flying animals are capable safe accurate landings while relying only visual information. Since this capability holds promise safely limited processing, it has served inspiration studies. The focus been ventral optic flow, measure translational velocity divided by height. Bees known flow controlling their speed height, also when In particular, landing, they keep constant. Valette et al. study control law that implements strategy, simulating moon. disadvantages sole two-fold. First, vertical dynamics lander left free. can have same constant value trajectory in which ascends accelerating descends decelerating. Thus, one directly indirectly assume some type descent profile, example introducing pitch Without additional information compute an optimal leads considerable expense propellant undefined final low-gate conditions. Second, case straight zero. case, e.g. terminal phase asteroid scenario, does not provide any how land Advanced Concepts Team, European Space Agency, dario.izzo@esa.int Exteroceptive observe entities external spacecraft, quantities within “body”.