Abstract: A detection system (1) having an optical sensor (3), a radar device (2) and a signal processor (4) communicatively connected with the optical sensor and the radar device. The signal processor comprises: a first detector (41, 410-413) for detecting a first object on the basis of a first signal coming from the optical sensor and determining at least one first property of the first object; a second detector (42, 420-421) for detecting a second object on the basis of a second signal coming from the radar device and determining at least one second property of that second object, and a signaling unit (43) for producing a signal if the at least one first property and the at least one second property satisfy a predetermined condition.

Abstract: A detection system (1) having an optical sensor (3), a radar device (2) and a signal processor (4) communicatively connected with the optical sensor and the radar device. The signal processor comprises: a first detector (41, 410-413) for detecting a first object on the basis of a first signal coming from the optical sensor and determining at least one first property of the first object; a second detector (42, 420-421) for detecting a second object on the basis of a second signal coming from the radar device and determining at least one second property of that second object, and a signaling unit (43) for producing a signal if the at least one first property and the at least one second property satisfy a predetermined condition.

Abstract: A sensor for generating a signal in response of a variation at the tactile face. The sensor comprises superposed transmitting and receiving layers, which are provided with electrodes for the supply and pick-up of electrical signals to the transmitting layer and from the receiving layer respectively. With a high acoustic impedance of the boundary medium adjacent to the transmitting layer and a low acoustic impedance of the boundary medium adjacent to the receiving layer or vice versa, the sum of the thicknesses of the transmitting and receiving layers is an odd number of v/4f. With similar impedances, either low or high, of the said boundary media the aforesaid sum is an even number of v/4f. v is the propagation velocity of the acoustic vibration in the material of the transmitting and receiving layers and f the frequency of the signal supplied.