Apparatus for monitoring the blind spot of a motor vehicle

Abstract

An apparatus for monitoring the blind spot of a motor vehicle has a mirror assembly with at least one mirror element that can be moved using an actuator, and a microphone assembly. The microphone assembly is designed to determine the sound direction, and the movable mirror element is in the form of a sound reflector.

Claims

1. An apparatus for monitoring a blind spot of a motor vehicle, the apparatus comprising: a mirror assembly with a first mirror element, and a second movable mirror element in a form of a sound reflector, wherein the second movable mirror element is movable from a first position to a second position, the first mirror element and the second movable mirror element forming a co-planar mirror surface with the second movable mirror element in the first position; an actuator to move the second movable mirror element; and a microphone assembly positioned to receive sound reflected from the second movable mirror element to determine a direction of the sound.

2. The apparatus of claim 1, wherein the first mirror element is a stationary mirror element.

3. The apparatus of claim 2, wherein the second movable mirror element and the first mirror element are foldably connected to one another.

4. The apparatus of claim 1, wherein the sound reflector has, in at least one direction of extent, a dimension of at least five times a sound wavelength of at least 3000 Hertz.

5. The apparatus of claim 1, wherein the microphone assembly has a plurality of microphones.

6. The apparatus of claim 1, wherein the microphone assembly is a micro-electric-mechanical system (MEMS) microphone assembly.

7. The apparatus of claim 1 wherein the second movable mirror element is rotated about a pivot axis relative to the first mirror element from the first position to the second position, wherein the second movable mirror element is connected to the first movable mirror element along the pivot axis.

8. The apparatus of claim 1 wherein the first mirror element and second movable mirror element are formed from a foldable mirror sheet.

9. A motor vehicle comprising: a blind spot assistant apparatus having: a mirror assembly with a first mirror element moveable relative to a second mirror element, the first mirror element forming a sound reflector, an actuator to move the first mirror element, and a microphone assembly having first and second microphones positioned to receive sound emitted by a road user and reflected from the first mirror element to determine a direction of the sound.

10. The motor vehicle of claim 9 further comprising a controller configured to receive signals from the first and second microphones, and determine the sound direction using a measurement of a sound propagation time difference between sound received by the first and second microphones.

11. The motor vehicle of claim 10 further comprising a turn signaling device; wherein the controller is configured to control the actuator to move the first mirror element in response to the turn signaling device being activated by a user.

12. The motor vehicle of claim 10 wherein the controller is further configured to output a warning signal to alert a user in response to the sound direction being indicative of the road user being in a blind spot of the vehicle.

13. The motor vehicle of claim 9 wherein the first mirror element is movable from a first position to a second position, wherein the first mirror element and the second mirror element form a co-planar mirror surface with the first mirror element in the first position.

14. The motor vehicle of claim 13 wherein the first mirror element is rotated about a pivot axis relative to the second mirror element from the first position to the second position.

15. The motor vehicle of claim 14 wherein the second mirror element is positioned between a driver of the vehicle and the first mirror element.

16. The motor vehicle of claim 14 wherein the first mirror element is connected to the second mirror element along the pivot axis.

17. The motor vehicle of claim 9 wherein the first mirror element and second mirror element are formed from a foldable mirror sheet.

18. The motor vehicle of claim 9 wherein the microphone assembly is a micro-electric-mechanical system (MEMS) microphone assembly.

19. The motor vehicle of claim 9 wherein the sound reflector of the first mirror element has a dimension of at least five times a sound wavelength of 5000 Hertz.

20. The motor vehicle of claim 9 wherein the first and second microphones are each omnidirectional microphones.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic illustration of a motor vehicle having a blind spot assistant.

(2) FIG. 2 shows further details and components of the blind spot assistant illustrated in FIG. 1.

DETAILED DESCRIPTION

(3) As required, detailed embodiments of the present disclosure are provided herein; however, it is to be understood that the disclosed embodiments are merely examples and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

(4) FIG. 1 illustrates a vehicle exterior mirror 18 of a motor vehicle 2 according to an embodiment. The motor vehicle 2 has a blind spot assistant 4 having an apparatus 6 for monitoring the blind spot of the motor vehicle 2, with which a blind spot of the vehicle exterior mirror 18 can be monitored. In this case, the blind spot is understood as meaning an area or region which cannot be seen by a motor vehicle driver by looking in the vehicle exterior mirror 18.

(5) In the present embodiment, the blind spot assistant 4 is designed to project a flashing light signal, as a visual warning signal, in the form of a symbol S onto a mirror surface 20 of a mirror assembly 8 of the vehicle exterior mirror 18 in response to a road user in the blind spot being captured by the apparatus.

(6) In the present embodiment, the mirror assembly 8 has a movable mirror element 14 and a stationary mirror element 16. In this case, the movable mirror element 14 and the stationary mirror element 16 are connected to one another in a foldable manner. In other words, the mirror surface 20 is produced from foldable glass. In the present embodiment, the movable mirror element 14 and the stationary mirror element 16 are therefore connected to one another along a pivot axis 22 and are simultaneously designed in one piece and without a gap, such that the movable mirror element and the stationary mirror element form a continuous mirror surface.

(7) FIG. 2 illustrates a schematic of the apparatus 6. The mirror assembly 8 has an actuator 12, for example a piezo actuator, for moving the movable mirror element 14 about the pivot axis 22 and relative to the stationary mirror element 16.

(8) In a first, starting position, the movable mirror element 14 and the stationary mirror element 16 are co-planar such that they form a flat mirror surface 20 without a gap-shaped transition between the movable mirror element 14 and the stationary mirror element 16 (as shown in FIG. 1). In a second, deflection position, and as shown in FIG. 2, the movable mirror element 14 is moved by actuating the actuator 12 to move the movable mirror element 14 relative to the stationary mirror element 16.

(9) The apparatus for monitoring the blind spot 6 also has a microphone assembly 10. In order to determine the sound direction, the microphone assembly 10 has a plurality of microphones. In the present example, the microphone assembly 10 has a first microphone 24a and a second microphone 24b which are arranged at a minimum distance of greater than zero from one another, or are spaced apart from one another. The microphone assembly is mounted to the vehicle.

(10) According to an example, the first microphone 24a and the second microphone 24b are MEMS microphones. These are, for example, condenser microphones having a silicon diaphragm arranged on a carrier, such as a processed silicon wafer. For example, the silicon diaphragm can be produced using surface micromechanics and further components may be provided for signal processing. In this case, surface micromechanics are understood as meaning the fact that mechanical structures are formed on a wafer surface by means of a plurality of etching and deposition operations. The particular advantage of this technology is that the micromechanical structures can be combined together with electrical circuits on a microchip.

(11) In other words, the microphone assembly 10 is a microsystem on a chip with integrated circuits or signal processing and sensors for capturing sound in the form of the first microphone 24a and the second microphone 24b. In other examples, the microphone assembly 10 having the first microphone 24a and the second microphone 24b may also be produced using other manufacturing technologies, for example, via silicon bulk mechanics or from plastic components which are applied to a carrier, e.g. via three-dimensional (3-D) printing. In this case, silicon bulk mechanics are understood as meaning that freestanding mechanical structures are obtained from a silicon wafer by means of etching on one or both sides. They are produced by etching silicon in alkaline solutions (e.g. potassium hydroxide solution) in a manner dependent on the crystal orientation; this process may be referred to as anisotropic wet etching.

(12) In contrast, 3-D printing is understood as meaning generative production methods in which workpieces are constructed in layers.

(13) During operation, for example in response to an activated turn signal, the movable mirror element 14 is changed to the position illustrated in FIG. 2 by actuating the actuator 12. Sound emitted by a road user in the blind spot is then deflected to the microphone assembly 10, wherein a measurement of the sound propagation time difference using the first microphone 24a and the second microphone 24b is used to determine the direction from which sound originates. These sensor signals are combined with other data by means of sensor data merging.

(14) A controller 26 is provided, and may be a part of a vehicle control system. The controller 26 is connected to the actuator 12 to control the movable mirror element 14 position. The controller 26 receives signals from the microphones in the microphone assembly 10, for example, as discrete signals from each microphone. The controller 26 is connected to other vehicle systems, such as the turn indicator system 30 to indicate that a lane change may be imminent, or to otherwise cause the controller to change the movable mirror to the deflected position. The controller is configured to, in response to receiving an input indicative of an imminent lane change or other input to monitor the blind spot, control the movable mirror element to the deflected position such that sound emitted by and originating from a road user in the vehicle blond spot is deflected to the microphone assembly. The controller uses data received from the microphones 24a, 24b in the microphone assembly to measure the sound propagation time difference using the first microphone 24a and the second microphone 24b, and determine a direction from which sound originates and if a road user is present in the blind spot. In the event of a road user being present in the blind spot of the vehicle, the controller activates the warning system 28 to alert the vehicle driver of a road user in the blind spot.

(15) It is thus possible to improve the accuracy when capturing road users in the blind spot.

LIST OF REFERENCE SYMBOLS

(16) 2 Motor vehicle 4 Blind spot assistant 5 Apparatus for monitoring the blind spot 8 Mirror assembly 10 Microphone assembly 12 Actuator 14 Movable mirror element 16 Stationary mirror element 18 Vehicle exterior mirror 20 Mirror surface 22 Pivot axis 24a Microphone 24b Microphone 26 Controller 28 Warning System 30 Turn Indicator System S Symbol

(17) While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure.