Device for monitoring the blind spots of motor vehicles

Abstract

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

Description

Technical Field

[0001] The invention relates to a device for monitoring a blind spot of a motor vehicle, a blind spot assistant having such a device, and a motor vehicle having such a blind spot assistant. Background Art

[0002] Blind spot aids (also called lane change aids) are driver assistance systems for warning the driver of a motor vehicle of an impending collision in the event of a lane change. Ultrasonic sensors, radar sensors, cameras or laser scanners can be used to capture road users or other vehicles approaching in an adjacent lane. The warning message for the driver of the motor vehicle can be set in different ways depending on whether the direction indicator ("turn signal") has been actuated.

[0003] If the turn signal is not activated, at most a visual warning may be provided to the driver. However, if the turn signal is active, a higher warning level may be activated and provided to the driver, where the warning is issued in a more urgent manner, typically visually by a rapidly flashing indicator light, typically in the area of ​​the exterior rearview mirror, audibly by a warning tone and / or haptically by vibration of the steering wheel, driver's seat surface or turn signal stalk.

[0004] Radar sensors can be used to capture road users in the blind spots of a motor vehicle's rearview mirror. However, the use of radar sensors requires the corresponding transmission and reflection of electromagnetic waves. For example, reflections at guardrails can be destructive.

[0005] Therefore, there is a need to show a way to improve accuracy when capturing road users in the blind spot of a vehicle. Summary of the invention

[0006] According to various embodiments of the invention, there is provided a device for monitoring a blind spot of a motor vehicle, the device having a mirror assembly and a microphone assembly, the mirror assembly having at least one mirror element that can be moved using an actuator. The microphone assembly is designed to determine the direction of sound, and the movable mirror element is in the form of a sound reflector.

[0007] In addition to other sensor signals, the sound radiation emitted by or originating from other road users in the blind spot is therefore detected and captured. The road user can be another vehicle that emits sounds such as road surface, tires, engines, transmissions, aerodynamics and brake noises, or other audible sounds. In other examples, the road user can be a pedestrian, a cyclist, etc. that emits sounds. These sensor signals are combined with other data by sensor data merging to improve the accuracy of capturing road users in the blind spot. In this case, the reflector element of the device is used to deflect or reflect the sound to the microphone assembly in a desired manner. For example, in response to an activated turn signal, an actuator can be provided to change the movable reflector element to a position where the sound emitted by the road user in the blind spot is deflected or reflected to the microphone assembly.

[0008] According to one embodiment, the mirror assembly has at least one fixed mirror element. The original function of a rearview mirror or sideview mirror of a motor vehicle is thus retained, in particular making it easier for the motor vehicle driver to observe the traffic situation behind, while the movable mirror is used to detect road users in the blind spot.

[0009] According to another embodiment, the movable mirror element and the fixed mirror element are connected to each other in a foldable manner. Thus, the movable mirror element and the fixed mirror element are foldably connected to each other along a pivot axis and are simultaneously formed as one piece, for example, as a foldable mirror. Thus, the mirror surface formed by the movable mirror element and the fixed mirror element has a gapless or continuous design, which makes it particularly easy for the driver of the motor vehicle to observe the traffic situation behind and provides a larger mirror surface when the movable mirror element is not folded or coplanar with the fixed element. The movable mirror element is movable relative to the fixed mirror element; however, it is contemplated that the fixed mirror element can be positioned by the driver relative to the vehicle to provide an appropriate rear view or side view as known in the art.

[0010] According to another embodiment, the sound reflector has a size of at least five times the wavelength of the sound wave in at least one extension direction. In one example, the sound wavelength is associated with audible noise and is located in the range of 20 Hz to 20,000 Hz. In another example, the sound wavelength is located in the range defined as 3,000-20,000 Hz, or in another example, is located in the range defined as 5,000-20,000 Hz, or in another example, is located in the range defined as 10,000-20,000 Hz. In another example, the sound wavelength can be greater than 20,000 Hz. Note that the length of the wavelength in meters decreases with the increase of hertz, and the length of the wavelength can be calculated according to the frequency using the speed of sound in air at a temperature of 20 degrees Celsius or 343 meters / second. This ensures a particularly effective deflection or reflection of the sound radiation of road users in the blind spot.

[0011] According to another embodiment, the microphone assembly has a plurality of microphones. The microphones are arranged with a minimum distance between each other greater than zero, so that they are spaced apart from each other and, by measuring the sound propagation time difference, allow the direction from which the sound originates to be determined. Thus, the directional microphone can be omitted, so that the microphone assembly comprises an omnidirectional microphone.

[0012] According to another embodiment, the microphone assembly is a microelectromechanical system (MEMS) microphone assembly. In this case, a MEMS microphone assembly is understood to mean a microsystem whose components have a minimum dimension of the order of magnitude of about one micrometer and interact as a system. The microphone in the MEMS microphone assembly can be a capacitive microphone in microsystem technology (MEMS microphone), in which a microdiaphragm that changes the capacitance is etched directly onto a silicon wafer. If the readout electronics have a preamplifier and an analog / digital converter and are integrated directly on the wafer next to the diaphragm in an application specific integrated circuit (ASIC) (e.g. as a component in complementary metal oxide semiconductor (CMOS) technology) so that the microphone has a digital output, such a device can also be called a digital microphone. They have small dimensions, low power consumption and good shielding against interfering signals and can be produced in a cost-effective manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of a motor vehicle having a blind spot assist device is shown;

[0014] Figure 2 Shows Figure 1 Another detail and components of the blind spot assist device shown in . DETAILED DESCRIPTION

[0015] As required, detailed embodiments of the present invention are provided herein; however, it should be understood that the disclosed embodiments are merely examples and may be implemented in various and alternative forms. These figures are not necessarily to scale; certain features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to use the present invention in various ways.

[0016] Figure 1 A vehicle exterior rearview mirror 18 of a motor vehicle 2 according to an embodiment is shown. The motor vehicle 2 has a blind spot assistant 4 with a device 6 for monitoring a blind spot of the motor vehicle 2, with which the blind spot of the vehicle exterior rearview mirror 18 can be monitored. In this case, a blind spot is understood to mean an area or region that the motor vehicle driver cannot see by looking into the vehicle exterior rearview mirror 18.

[0017] In the present embodiment, the blind spot assist device 4 is designed to project a flashing signal in the form of a symbol S as a visual warning signal onto the mirror surface 20 of the reflector assembly 8 of the vehicle's exterior rearview mirror 18 in response to a road user in the blind spot captured by the device.

[0018] In the present embodiment, the reflector assembly 8 has a movable reflector element 14 and a fixed reflector element 16. In this case, the movable reflector element 14 and the fixed reflector element 16 are connected to each other in a foldable manner. In other words, the mirror surface 20 is made of foldable glass. In the present embodiment, the movable reflector element 14 and the fixed reflector element 16 are therefore connected to each other along the pivot axis 22 and are simultaneously designed as one piece and without a gap, so that the movable reflector element and the fixed reflector element form a continuous mirror surface.

[0019] Figure 2 A schematic diagram of the device 6 is shown. The mirror assembly 8 has an actuator 12 , such as a piezoelectric actuator, for moving a movable mirror element 14 about a pivot axis 22 and relative to a fixed mirror element 16 .

[0020] In a first starting position, the movable mirror element 14 and the fixed mirror element 16 are coplanar, so that they form a flat mirror surface 20 without a gap-shaped transition (eg, Figure 1 In the second deflected position, and as Figure 2 As shown, the movable mirror element 14 is moved by actuating the actuator 12 so that the movable mirror element 14 moves relative to the fixed mirror element 16 .

[0021] The device 6 for monitoring a blind spot also has a microphone assembly 10. In order to determine the direction of a sound, the microphone assembly 10 has a plurality of microphones. In this example, the microphone assembly 10 has a first microphone 24a and a second microphone 24b, which are arranged such that the minimum distance between them is greater than zero or are spaced apart from each other. The microphone assembly is mounted on a vehicle.

[0022] According to an example, the first microphone 24a and the second microphone 24b are MEMS microphones. These are, for example, capacitive microphones having a silicon diaphragm arranged on a carrier, for example a processed silicon wafer. For example, the silicon diaphragm can be manufactured using surface micromachining, and other components can be provided for signal processing. In this case, surface micromachining is understood to mean the fact that mechanical structures are formed on the surface of the wafer by a plurality of etching and deposition operations. A particular advantage of this technology is that the micromechanical structures can be combined with circuits on a microchip.

[0023] In other words, the microphone assembly 10 is a microsystem on a chip with an integrated circuit or a signal processor and a sensor in the form of a first microphone 24a and a second microphone 24b for capturing sound. In other examples, the microphone assembly 10 with the first microphone 24a and the second microphone 24b can also be produced using other manufacturing techniques (e.g. via silicon bulk mechanics) or from a plastic part applied to a carrier (e.g. via three-dimensional (3-D) printing). In this case, silicon bulk mechanics is understood to mean that independent mechanical structures are obtained from a silicon wafer by etching on one or both sides. They are prepared by etching silicon in an alkaline solution (e.g. potassium hydroxide solution) in a manner that depends on the crystal orientation; this process can be called anisotropic wet etching.

[0024] In contrast, 3-D printing is understood to mean a generative production method in which workpieces are constructed in layers.

[0025] During operation, for example in response to an activated turn signal, the movable mirror element 14 is changed to Figure 2 The sound emitted by the road user in the blind spot is then deflected into the microphone assembly 10, where the sound propagation time difference is measured using the first microphone 24a and the second microphone 24b to determine the direction from which the sound is generated. These sensor signals are combined with other data by sensor data merging.

[0026] A controller 26 is provided, and the controller 26 can be part of the vehicle control system. The controller 26 is connected to the actuator 12 to control the position of the movable reflector element 14. 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 a turn indicator system 30, to indicate that a lane change may be imminent, or otherwise cause the controller to change the movable reflector to a deflected position. The controller is configured to control the movable reflector element to a deflected position in response to receiving an input indicating an imminent lane change or other inputs to monitor the blind spot, so that the sound emitted by and originating from the road user in the vehicle blind spot is deflected to the microphone assembly. The controller uses the 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 determines the direction from which the sound comes and whether the road user is present in the blind spot. In the case where the road user appears in the blind spot of the vehicle, the controller activates the warning system 28 to warn the road user in the blind spot of the vehicle driver.

[0027] As a result, it is possible to improve accuracy when capturing road users in blind spots.

[0028] List of reference numerals:

[0029] 2 Motor Vehicles

[0030] 4 Blind spot assist device

[0031] 5 Equipment for monitoring blind spots

[0032] 8 Reflector assembly

[0033] 10 Microphone assembly

[0034] 12 Actuator

[0035] 14 Movable mirror elements

[0036] 16 Fixing the reflector element

[0037] 18 Vehicle exterior mirrors

[0038] 20 Mirror

[0039] 22 Pivot axis

[0040] 24a Microphone

[0041] 24b Microphone

[0042] 26 Controller

[0043] 28 Warning system

[0044] 30 Turn indicator system

[0045] S symbol

[0046] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the present invention. On the contrary, the words used in the specification are descriptive rather than restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of the present invention. In addition, the features of various implementation embodiments may be combined to form other embodiments of the present invention.

Claims

1. A device for monitoring a blind spot of a motor vehicle, the device comprising: a reflector assembly having a first reflector element and a movable second reflector element in the form of a sound reflector, wherein the second reflector element is movable from a first position to a second position, and when the second reflector element is in the first position, the first reflector element and the second reflector element form a coplanar mirror surface; an actuator for moving the second reflector element; as well as A microphone assembly is positioned to receive sound reflected from the second reflector element to determine the direction of sound emanating from a road user.

2. The device according to claim 1, wherein The first reflector element is a fixed reflector element.

3. The device according to claim 1, wherein: The second mirror element and the first mirror element are foldably connected to each other.

4. The device according to claim 1, wherein: The sound reflector has a dimension in at least one extension direction of at least five times the wavelength of sound waves at at least 3000 Hz.

5. The device according to claim 1, wherein: The microphone assembly has a plurality of microphones.

6. The device according to claim 1, wherein: The microphone assembly is a micro-electro-mechanical system (MEMS) microphone assembly.

7. A motor vehicle comprising: A blind spot assist device, the blind spot assist device comprising: a reflector assembly having a first reflector element movable relative to a second reflector element, the first reflector element forming a sound reflector, wherein the first reflector element is movable from a first position to a second position, wherein when the first reflector element is in the first position, the first reflector element and the second reflector element form a coplanar mirror surface; an actuator for moving the first mirror element, and A microphone assembly has first and second microphones positioned to receive sound emitted by a road user and reflected from the first reflector element to determine a direction of the sound emitted by the road user.

8. The motor vehicle of claim 7 further comprising a controller configured to receive signals from the first and second microphones and to determine a direction of sound emanating from a road user using a measure of a sound propagation time difference between sounds received by the first and second microphones.

9. The motor vehicle of claim 8, further comprising a turn signal device; in, The controller is configured to control the actuator to move the first reflector element in response to activation of the turn signal device by a user.

10. The motor vehicle of claim 8, wherein: The controller is also configured to output a warning signal to warn the road user in response to a direction of a sound indicating that the road user is in a blind spot of the motor vehicle.

11. The motor vehicle of claim 7, 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.

12. A motor vehicle according to claim 11, wherein: The second mirror element is positioned between a driver of the motor vehicle and the first mirror element.

13. The motor vehicle of claim 11, wherein: The first mirror element is connected to the second mirror element along the pivot axis.

14. The motor vehicle of claim 7, wherein: The first reflector element and the second reflector element are formed by foldable mirror sheets.

15. The motor vehicle of claim 7, wherein: The microphone assembly is a micro-electro-mechanical system (MEMS) microphone assembly.

16. The motor vehicle of claim 7, wherein: The sound reflector of the first mirror element has a size of at least five times the wavelength of sound waves at 5000 Hz.

17. The motor vehicle of claim 7, wherein: The first and second microphones are both omnidirectional microphones.

18. A method of controlling a blind spot assistance device in a vehicle, the method comprising: controlling, via the controller, using the actuator to control the movable mirror element to a deflected position relative to the fixed mirror element in response to receiving the turn indicator signal; receiving, via the controller, first and second signals from first and second microphones positioned to receive sound emitted by a road user and deflected from the movable mirror element; as well as activating a warning system via the controller in response to determining a direction of sound indicative of a road user in a blind spot of the vehicle, determining the direction of the road user's sound using a measure of a sound propagation time difference between sounds received by the first and second microphones; In the absence of the turn indicator signal, the movable mirror element is controlled via the controller to a coplanar position relative to the fixed mirror element.

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