A predictive collision radar system in a vehicle incorporates a first antenna and a guard antenna, the associated radiation patterns of which overlap with one another, but the radiation pattern of the guard antenna is broader than that of the first antenna. For example, the vehicle driving assist system executes accelerator pedal actuation reaction force control such that an actuation reaction force is generated in accordance with a risk potential that expresses a degree of convergence between the host vehicle and a preceding obstacle. The present invention discloses improved screens for this system as well as methods of manufacturing said improved screens. The brightness obtaining module is configured for obtaining the brightness of a set of areas in the image corresponding to a set of preset portions of each human face. The processor reads the first firmware image from the ROM and verifies the state of the first firmware image.