Sensor system and method, in particular for determining distances

• US 20040102919A1
• Filed: 08/08/2003
• Published: 05/27/2004
• Est. Priority Date: 08/22/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hoetzel, Juergen, Eckel, Matthias
• Granted Patent: US 7,039,549 B2
• Time in Patent Office: Days
• US Class Current: 702/159
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 15/18 wherein range gates are used
• CPC Class Codes: G01S 7/292 Extracting wanted echo-signals
• CPC Class Codes: G01S 7/52006 with provision for compensating the effects of temperature
• CPC Class Codes: G01S 7/527 Extracting wanted echo signals Doppler systems G01S15/50
• CPC Class Codes: G01S 7/529 Gain of receiver varied automatically during pulse-recurrence period for seismic signals G01V1/245

Abstract

The invention relates inter alia to a sensor system (50) used for distance calculation. A setpoint selection unit (58) controls an amplifier unit (54) and/or a sensor unit (52) depending on selectable setpoints for a cycle of detection. Contrary to known sensor systems, different detection cycles can be carried out in a very simple manner.

Claims

1. A sensor system (50) for determining distances, comprising a sensor unit (52) which operates in different detection areas during a detection cycle and generates, as a function of the detection area, at least one sensor signal (62) whose signal values are affected by an object located in the detection area;

a controllable amplifier unit (54) for amplifying the sensor signal (62) as a function of the value of a gain parameter (VF2); and

a gain predefining unit (58) for predefining different values for the gain parameter (VF2) during a detection cycle,

wherein the gain predefining unit (58) sets a constant gain parameter for the detection area as a function of the detection area to be examined;

the gain predefining unit (58) predefines different threshold values (108) during a detection cycle, which are different for a plurality of consecutive detection areas; and

, as a function of the result of the comparison of the amplified sensor signal (64) to the threshold values, it is determined, whether an object of a certain size is located in the detection area.

2. The sensor system (50) as recited in claim 1, wherein the gain predefining unit (58) contains a processor which executes instructions of a control program.

3. The sensor system (50) as recited in claim 2, wherein the gain predefining unit (58) is connected to the sensor unit (52) and the amplifier unit (54) via transmission paths (66) for transmitting data words having a predefined number of bit positions, the gain predefining unit (58) transmits a data word to the sensor unit (52) and/or the amplifier unit (54), the sensor unit (52) sets the detection areas as a function of the data word(s) received, and/or the amplifier unit (54) sets the value of the gain parameter (VF2) as a function of the data word(s) received.

4. The sensor system (50) as recited in claim 2 or 3, characterized by an analog/digital converter unit (56), connected to the output of the amplifier unit (54), which generates a data word as a function of the signal value at its input and transmits it to the gain predefining unit (58), the gain predefining unit (58) causing a detection result to be output as a function of the data words received during a detection cycle.

5. The sensor system (50) as recited in one of the preceding claims,

characterized by a temperature sensor (68) connected to the gain predefining unit (58), the output signal (66) of the temperature sensor depending on the temperature at which the sensor system (50) operates, the gain predefining unit (58) controlling the sensor unit (52) and/or the amplifier unit (54) also as a function of the output signal of the temperature sensor (68).

6. The sensor system (50) as recited in one of the preceding claims,

wherein the sensor unit (52) contains at least one transmitter unit for transmitting electromagnetic waves or sound waves, and at least one receiver unit for receiving electromagnetic waves or sound waves which are reflected by the object.

7. A method of determining distances, in which a sensor unit (52) operates in different detection areas during a detection cycle;

the sensor unit (52) generates at least one sensor signal (62), whose signal values are affected by an object located in the detection area;

the sensor signal (62) is amplified as a function of a gain parameter (VF2);

different values of the gain parameter (VF2) are predefined during a detection cycle, wherein a constant gain factor is set for the detection area as a function of the detection area to be examined, a threshold value is used for the detection area, and as a function of a comparison with the threshold value, it is determined, whether an object of a certain size is located in the detection area.