THERMAL CONTROL OF A SENSOR DEVICE

Abstract

A method for operating a sensor device for determining a road condition. Beams of at least one beam source are generated and emitted into a scanning area. Beams that are scattered or reflected back from the scanning area are ascertained by at least one detector and evaluated for determining the road condition with the aid of the control unit coupled to the detector. Temperature-dependent influences on at least one component of the sensor device are ascertained with the aid of at least one sensor. The temperature-dependent influences on the component of the sensor device are compensated for by a heating device and/or a cooling device and/or during the evaluation by the control unit. A control unit and a computer program are also described.

Claims

1-15. (canceled)

16. A method for operating a sensor device for determining a road condition, the method comprising the following steps: generating and emitting beams into a scanning area using at least one beam source; ascertaining beams that are scattered back or reflected from the scanning area using at least one detector; and evaluating the ascertained beam for determining the road condition using a control unit coupled to the detector; ascertaining temperature-dependent influences on at least one component of the sensor device using at least one sensor; and compensating for the temperature-dependent influences on the component of the sensor device by a heating device and/or a cooling device and/or during the evaluation by the control unit.

17. The method as recited in claim 16, wherein the component of the sensor device is situated on at least one thermally conductive circuit board, wherein the circuit board and/or the component situated on the circuit board is thermally adjusted by the heating device and/or the cooling device.

18. The method as recited in claim 16, wherein a temperature of the at least one beam source and/or of the circuit board and/or of the detector, is measured by at least one temperature sensor and received by the control unit.

19. The method as recited in claim 18, wherein the temperature is used to ascertain a radiation power of the generated beams in a mathematical function and/or in a simulation and/or in a temperature radiation power characteristic curve.

20. The method as recited in claim 18, wherein the measured temperature is used to take into account a temperature-dependent wavelength shift of the beam source and/or to take into account thermal influences on the detector.

21. The method as recited in claim 16, wherein a radiation power of the generated beams is measured by an intensity sensor and received by the control unit.

22. The method as recited in claim 21, wherein the radiation power of the generated beams is measured directly at the beam source and/or indirectly via a beam-guiding connection and/or at a scattered radiation of the beam source using the intensity sensor.

23. The method as recited in claim 21, wherein a temperature dependency of the intensity sensor is compensated using a mathematical function and/or a comparison chart.

24. A sensor device, comprising: at least one circuit board including at least one beam source configured to generate and emit beams into a scanning area, and at least one detector configured to receive beams that are reflected or scattered from the scanning area; wherein the sensor device is connectable to a control unit configured to: evaluate the received beams for determining the road condition; ascertain temperature-dependent influences on at least one component of the sensor device using at least one sensor; and compensate for the temperature-dependent influences on the component of the sensor device by a heating device and/or a cooling device and/or during the evaluation by the control unit

25. The sensor device as recited in claim 24, wherein the at least one sensor is a temperature sensor and/or as an intensity sensor, and the at least one beam source includes a temperature-independent central wavelength.

26. The sensor device as recited in claim 24, wherein at least one scattered-light protection is situated in an area of the at least one detector.

27. The sensor device as recited in claim 26, wherein at least one bandpass filter is situated in a beam path of the beams that are reflected or scattered back from the scanning.

28. The sensor device as recited in claim 27, wherein the at least one bandpass filter is situated at the scattered-light protection of the detector, the bandpass filter, the scattered-light protection, and the detector being connected to one another.

29. A control unit configured to operate a sensor device for determining a road condition, the control unit configured to: generate and emit beams into a scanning area using at least one beam source; ascertain beams that are scattered back or reflected from the scanning area using at least one detector; and evaluate the ascertained beam for determining the road condition; ascertain temperature-dependent influences on at least one component of the sensor device using at least one sensor; and compensate for the temperature-dependent influences on the component of the sensor device by a heating device and/or a cooling device and/or during the evaluation by the control unit.

30. A non-transitory machine-readable memory medium on which is stored a computer program including commands for operating a sensor device for determining a road condition, the commands, when executed by a control unit, causing the control unit to perform the following steps: generating and emitting beams into a scanning area using at least one beam source; ascertaining beams that are scattered back or reflected from the scanning area by at least one detector; and evaluating the ascertained beam for determining the road condition; ascertaining temperature-dependent influences on at least one component of the sensor device using at least one sensor; and compensating for the temperature-dependent influences on the component of the sensor device by a heating device and/or a cooling device and/or during the evaluation by the control unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 shows a schematic top view of a sensor device according to one specific embodiment of the present invention.

[0040] FIG. 2 shows a schematic sectional illustration of the sensor device from FIG. 1.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0041] FIG. 1 shows a schematic top view of a sensor device 1 according to one specific embodiment. Sensor device 1 includes a circuit board 2.

[0042] Circuit board 2 is shaped as a square by way of example and is manufactured from a material having good thermal conductivity, such as metal, for example. The thermal conductivity of circuit board 2 may thus be increased.

[0043] A detector 4 is situated in the center of circuit board 2 of sensor device 1. Detector 4 may be for example designed as a CCD sensor, a CMOS sensor, or as a photodiode, such as for example a PIN photodiode. A scattered-light protection 6 is situated on the periphery around detector 4. If detector 4 has a cylindrical shape, scattered-light protection 6 has a tubular design and accommodates detector 4 on the inside in a form-locked manner. scattered-light protection 6 may have different designs depending on the type of detector 4. For example, scattered-light protection 6 may have a square or rectangular shape in the case of a detector 4 in SMD construction. Alternatively or additionally, scattered-light protection 6 may be already integrated into detector 4. Scattered-light protection 6 delimits detector 4 radially R or along a lateral surface M of detector 4. Detector 4 may include its own reception optics or an integrated reception optics, such as for example a lens.

[0044] Scattered-light protection 6 may top detector 4 in axial direction A. A bandpass filter 8 is situated at the end side of scattered-light protection 6. In this way, incident beams may transmit only specific wavelengths to detector 4 through bandpass filter 8.

[0045] Sensor device 1 further includes four beam sources 10 situated in a row on circuit board 2. Beam sources 10 may be situated in any arbitrary number and in any arbitrary form on circuit board 2. For example, only one beam source 10 may be provided. Alternatively or additionally, several beam sources 10 may be positioned circularly around scattered-light protection 8. According to the specific embodiment, beam sources 10 are designed as infrared LEDs. Beam sources 10 may be operated successively, i.e., in an order one after another, in an activated and deactivated manner.

[0046] A temperature sensor 12 and an intensity sensor 14 are situated on the circuit board adjacent to beam sources 10. Temperature sensor 12 is designed as a resistance temperature sensor, for example, which is thermally conductively coupled to circuit board 2. Since temperature sensor 12 is directly positioned at beam sources 10, the temperature of beam sources 10 may be monitored with the aid of temperature sensor 12.

[0047] Intensity sensor 14 is designed as a monitoring photodiode and is capable of measuring the scattered light emitted by beam sources 10 and thus used to monitor the radiation power of beam sources 10.

[0048] FIG. 2 shows sensor device 1 from FIG. 1 laterally in a cross section. In this way, the form-locked position of scattered-light protection 8 around detector 4 may be illustrated.

[0049] Beam sources 10 generate beams 16 that are emitted into a scanning area 18. Generated beams 16 may be shaped by one or several optics prior to being emitted.

[0050] Generated beams 16 may hit obstacles 20, such as for example objects or a roadway, in scanning area 18. Generated beams 16 may be reflected or scattered back from obstacle 20 to sensor device 1. Beams 22, which are reflected or scattered back to sensor device 1, may be subsequently blocked by bandpass filter 8 or transmitted by the bandpass filter to detector 4.

[0051] Circuit board 2 is designed in a temperature-stabilized manner according to the exemplary embodiment. For this purpose, a Peltier element 24 is situated on a back side of circuit board 2. Peltier element 24 is used as a cooling element and as a heating element for adjusting a temperature of circuit board 2 and of components 4, 6, 10, 12, 14 situated on circuit board 2.

[0052] Beams 22 transmitted to detector 4 may be converted into electrical signals and received by a control unit 26. Control unit 26 is connected to strip conductors 3 of circuit board 2 and may read or activate components 4, 6, 10, 12, 14, 24. In this way, control unit 26 may receive and evaluate the measured values of sensors or detectors 4, 12, 14. In parallel thereto, control unit 26 may activate and control beam sources 10 and Peltier element 24.

[0053] Control unit 26 includes a machine-readable memory medium 28 that has a program for operating sensor device 1. In this way, control unit 26 may in particular carry out a road condition determination based on the measured values of detector 4. The measured values of temperature sensor 12 and of intensity sensor 14 may be used by control unit 26 to compensate for the thermal influences on detector 4 and beam sources 10.

[0054] The thermal influences may be taken into account by control unit 26 during the evaluation or by adjusting the temperature via Peltier element 24.