LIDAR SYSTEM AND VEHICLE

Abstract

A LIDAR system. The LIDAR system includes a light source and a bandpass filter which is situated in a reception path of the LIDAR system. The reception path being configured to receive light emitted by the light source which was reflected in surroundings of the LIDAR system. A spectral transmission width of the bandpass filter is configured to be narrower than a spectral emission width of a light beam emitted by the light source. A vehicle, which includes a LIDAR system, is also provided.

Claims

1-10. (canceled)

11. A LIDAR system, comprising: a light source; and a bandpass filter situated in a reception path of the LIDAR system, the reception path being configured to receive light emitted by the light source, which was reflected in surroundings of the LIDAR system; wherein a spectral transmission width of the bandpass filter is configured to be narrower than a spectral emission width of a light beam emitted by the light source.

12. The LIDAR system as recited in claim 11, wherein the spectral transmission width is no greater than 95% of the spectral emission width.

13. The LIDAR system as recited in claim 11, wherein the LIDAR system is configured to adapt a temperature control of the light source to a temperature-dependent change of the bandpass filter.

14. The LIDAR system as recited in claim 13, further comprising: a temperature stabilization unit configured to regulate the temperature control of the light source in such a way that a central wavelength of the light sources agrees with a central wavelength of the bandpass filter.

15. The LIDAR system as recited in claim 14, wherein the temperature stabilization unit includes a heating element or a Peltier element to regulate the temperature control of the light source.

16. The LIDAR system as recited in claim 14, wherein the temperature stabilization unit includes a temperature sensor configured to measure a present operating temperature of the bandpass filter.

17. The LIDAR system as recited in claim 11, further comprising: a rotatably attached mirror to effectuate a beam deflection.

18. The LIDAR system as recited in claim 11, further comprising: a rotatably attached platform carrying a transmission path, which includes the light source, and the reception path, to effectuate a beam deflection.

19. The LIDAR system as recited in claim 11, wherein the LIDAR system is configured to emit a laser line using the light source, and to generate an optical image using the reception path, a line detector being provided in the reception path to generate the optical image.

20. A vehicle, comprising: a LIDAR system including: a light source, and a bandpass filter situated in a reception path of the LIDAR system, the reception path being configured to receive light emitted by the light source, which was reflected in surroundings of the LIDAR system, wherein a spectral transmission width of the bandpass filter is configured to be narrower than a spectral emission width of a light beam emitted by the light source; wherein the LIDAR system is electrically connected to a battery of the vehicle for operating the LIDAR system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Exemplary embodiments of the present invention are described in greater detail based on the figures and the following description.

[0022] FIG. 1 shows a first specific embodiment of the LIDAR system according to the present invention in a top view.

[0023] FIG. 2 shows a schematic illustration of a spectral transmission width B.sub.T of the bandpass filter in the first specific embodiment, based on a spectral emission width B.sub.E of a light beam emitted by the light source.

[0024] FIG. 3 shows a second specific embodiment of the LIDAR system according to the present invention in a top view.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0025] FIG. 1 shows a LIDAR system 1 in a first specific embodiment according to the present invention in a top view. LIDAR system 1 includes a light source 2 and a bandpass filter 3. Bandpass filter 3 is situated in a reception path of LIDAR system 1. The reception path is configured to receive light emitted by light source 2 which was reflected in surroundings of LIDAR system 1. For this purpose, the reception path includes a line detector 4, here, more precisely, a silicon photomultiplier (SiPM) array, and a beam shaping optics 5, here simplified as a collecting lens. In this exemplary embodiment, bandpass filter 3 is situated in the reception path between beam shaping optics 5 and line detector 4, but could also be situated in another location in the reception path, for example upstream from beam shaping optics 5.

[0026] In the first specific embodiment according to FIG. 1, LIDAR system 1 furthermore includes a fixed semipermeable mirror 6, which is configured to direct light emitted by light source 2 onto a rotatably attached mirror 7 of LIDAR system 1, here at a 90° angle, which in turn is configured to effectuate a beam deflection into the surroundings of LIDAR system 1, in the present exemplary embodiment a horizontal beam deflection into the surroundings. Rotatably attached mirror 7 is situated on a rotatable support plate 8, torque-proof with respect thereto. Rotatable support plate 8 is situated in an electromechanically rotatable manner with respect to light source 2 and line detector 4. This is thus a so-called “rotating mirror LIDAR system.” Semipermeable mirror 6 is furthermore configured to allow light which is incident again to pass to beam shaping optics 5 in the reception path. Semipermeable mirror 6 is thus situated both in the reception path and in the transmission path of LIDAR system 1.

[0027] In specific embodiments not shown, bandpass filter 3 or a further bandpass filter (not shown), which may have identical or similar properties as bandpass filter 3, may be situated upstream from semipermeable mirror 6 in the reception path, i.e., in particular, be situated between semipermeable mirror 6 and rotatably attached mirror 7. This means that bandpass filter 3 or the further bandpass filter may be situated both upstream from semipermeable mirror 6 in the reception path and at the same time also downstream from semipermeable mirror 6 in the transmission path.

[0028] A spectral transmission width of bandpass filter 3 is configured to be narrower than a spectral emission width of a light beam emitted by light source 2. A significant portion of the optical power is laterally curtailed by bandpass filter 3, and only a portion of the optical power is transmitted. More precisely, the spectral transmission width, denoted by B.sub.T, is no greater than 95% of the spectral emission width, denoted by B.sub.E, as is apparent in FIG. 2. Wavelength A of the light beam is plotted on the x axis of the schematic diagram shown in FIG. 2, and intensity I of the light beam as a function of wavelength λ is plotted on the y axis. Spectral transmission width B.sub.T is approximately greater than 40% and no greater than 60% of spectral emission width B.sub.E. The fractions of the received light wavelength which are outside spectral transmission width B.sub.T are not transferred to line detector 4. In this way, even though the spectrum of the light beam emitted by light source 2 is curtailed in the reception path before striking line detector 4, background light may be filtered out better, which, depending on the situation, may be more important for the proper functioning of LIDAR system 1.

[0029] LIDAR system 1 is furthermore configured to adapt a temperature control of light source 2 to a temperature-dependent change of bandpass filter 3. For this purpose, LIDAR system 1 includes a temperature stabilization unit 9, which is configured to regulate the temperature control of light source 2 in such a way that a central wavelength of light sources 2 agrees with a central wavelength of bandpass filter 3. The effect of this regulation is also apparent in FIG. 2. The maximum of intensity I, i.e., the central wavelength of light source 2, is namely at the same wavelength λ there as the central wavelength of spectral transmission width B.sub.T of bandpass filter 3 illustrated as a rectangle. Temperature stabilization unit 9 includes a heating element 10 to regulate the temperature control of light source 2. Temperature stabilization unit 9 furthermore includes a temperature sensor 11 to measure a present operating temperature of bandpass filter 3. LIDAR system 1 includes a control unit 12, which is connected to temperature stabilization unit 9 for the data exchange and which is configured to evaluate the measurement of temperature sensor 11 and to control temperature stabilization unit 9, to operate heating element 10 in accordance with the measured temperature of bandpass filter 3, in order to regulate the temperature control of light source 2. In this way, the two central wavelengths remain in agreement over the time, even if the operating temperature of bandpass filter 3 changes. This may effectively prevent that, in particular, the maximum of intensity I of the light beam migrates out of the transmission width of bandpass filter 3 as a result of the temperature.

[0030] FIG. 3 finally shows a LIDAR system 1 in a second specific embodiment according to the present invention in a top view. In many respects, the design is identical to the design of the first specific embodiment from FIG. 1, which is why repetition is dispensed with. Bandpass filter 3 is again configured as explained based on FIG. 2. However, in the second specific embodiment LIDAR system 1, instead of the separately rotatably attached mirror 7 and support plate 8, includes a rotatable platform 13 carrying a transmission path, which includes light source 2, and the reception path to effectuate a beam deflection. In this exemplary embodiment, this is thus a so-called “rotating platform LIDAR system.” The beam deflection again takes place in the horizontal direction. In this exemplary embodiment, heating element 10 is replaced by a Peltier element 14, which also enables a cooling of light source 2.

[0031] In both specific embodiments, LIDAR system 1 is configured to emit a laser line with the aid of light source 2, and to generate an optical image with the aid of the reception path, line detector 4 being provided in the reception path to generate the optical image. In both specific embodiments, it is possible to use “standard lasers” as light source 2 in the reception path, even in the case of LIDAR systems 1 having narrow optical bandpass filters 3, i.e., a small spectral transmission width compared to the spectral emission width of light source 2. In other words, bandpass filter 3 is narrower than the spectral width (including all tolerances) of the radiation emitted by light source 2. Both specific embodiments are situated in a vehicle not shown in greater detail, LIDAR system 1 in each case being electrically connected to a battery (not shown) of the vehicle to operate LIDAR system 1.

[0032] The two specific embodiments illustrate that a laser having a wide emission spectrum may be used as light source 2 to be able to use an efficient (and/or already available) laser. The laser may be thermally stabilized, in particular, as a function of the operating temperature of the reception-side bandpass filter 3.

[0033] Although the present invention was illustrated and described in greater detail by preferred exemplary embodiments, the present invention is not limited by the described examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of protection of the present invention.