A solid-state Lidar system includes a photodetector, or an array of photodetectors that is essentially fixed in place relative to a carrier, e.g., a vehicle. Light is emitted into the field of view of the photodetector and the photodetector detects light that is reflected by an object in the field of view. For example, a Flash Lidar system emits pulses of light, e.g., laser light, into essentially the entire field of view. The detection of reflected light is used to generate a 3D environmental map of the surrounding environment. The time of flight of the reflected photon detected by the photodetector is used to determine the distance of the object that reflected the light.
The solid-state Lidar system may be mounted on a vehicle to detect objects in the environment surrounding the vehicle and to detect distances of those objects for environmental mapping. The output of the solid-state Lidar system may be used, for example, to autonomously or semi-autonomously control operation of the vehicle, e.g., propulsion, braking, steering, etc. Specifically, the system may be a component of or in communication with an advanced driver-assistance system (ADAS) of the vehicle.
With reference to the Figures, wherein like numerals indicate like parts throughout the several views, a system 10 is generally shown. The system 10 may be a component of a light detection and ranging (Lidar) system 12. Specifically, the system 10 may be an illumination system of the Lidar system 12. The system 10 includes an optical element 14 and a light emitter 16 aimed at the optical element 14. The system 10 includes a controller 18 in communication with the light emitter 16 and an electrical circuit 20 across the optical element 14 and in communication with the controller 18.
Since the electrical circuit 20 is across the optical element 14, the electrical circuit 20 indicates the integrity of the optical element 14, i.e., whether the optical element 14 is intact or damaged. In the event the optical element 14 is intact, i.e., undamaged, the electrical circuit 20 is intact. In the event the optical element 14 is damaged, the electrical circuit 20 is broken. The voltage across the electrical circuit 20 when the electrical circuit 20 is broken is different than the voltage across the electrical circuit 20 when the electrical circuit 20 is intact. These different voltages are used to control the operation of the light emitter 16, as described further below. Specifically, the system 10 is designed such that the light emitter 16 is operational when the electrical circuit 20 is intact, i.e., indicating the optical element 14 is intact, and such that the light emitter 16 is not operational when the electrical circuit 20 is broken, i.e., indicating that the optical element 14 is damaged. The optical element 14, when intact, alters light from the light emitter 16, e.g., shapes the light, prior to exiting the system 10. When the optical element 14 is damaged, the optical element 14 may not properly alter the light from the light emitter 16, resulting in undesirable light emissions exiting the system 10. Thus, the inoperability of the light emitter 16 when the optical element 14 is damaged prevents all or substantially all undesirable light emission from the system 10.
One example of the electrical circuit 20 is shown in
As set forth above, the system 10 may be a component of a Lidar system 12. With reference to
The Lidar system 12 is shown in
The Lidar system 12 may be a solid-state Lidar system. In such an example, the Lidar system 12 is stationary relative to the vehicle 30. For example, the Lidar system 12 may include a casing 32 (shown in
As a solid-state Lidar system, the Lidar system 12 may be a flash Lidar system. In such an example, the Lidar system 12 emits pulses of light into the field of illumination FOI. More specifically, the Lidar system 12 may be a 3D flash Lidar system that generates a 3D environmental map of the surrounding environment, as shown in part in
In such an example, the Lidar system 12 is a unit. For example, with reference to
The casing 32, for example, may be plastic or metal and may protect the other components of the Lidar system 12 from environmental precipitation, dust, etc. In the alternative to the Lidar system 12 being a unit, components of the Lidar system 12, e.g., the light emitter 16 and the light-receiving system, may be separated and disposed at different locations of the vehicle 30.
With continued reference to
With reference to
As set forth above, the Lidar system 12 may be a staring, non-moving system. As another example, the Lidar system 12 may include elements to adjust the aim of the Lidar system 12. For example, the Lidar system 12 may include a beam steering device (not shown) that directs the light from the light emitter 16 into the field of illumination FOI. The beam steering device may be a micromirror. For example, the beam steering device may be a micro-electro-mechanical system 10 (MEMS) mirror. As an example, the beam steering device may be a digital micromirror device (DMD) that includes an array of pixel-mirrors that are capable of being tilted to deflect light. As another example, the MEMS mirror may include a mirror on a gimbal that is tilted, e.g., by application of voltage. As another example, the beam steering device may be a liquid-crystal solid-state device.
As set forth above, the light emitter 16 is aimed at the optical element 14. Specifically, the optical element 14 includes a light-shaping region 36 (described further below) and the light emitter 16 is aimed at the light-shaping region 36. The light emitter 16 may be aimed directly at the optical element 14 or may be aimed indirectly at the optical element 14 through intermediate reflectors/deflectors, diffusers, optics, etc.
The light-shaping region 36 of the optical element 14 shapes the light from the light emitter 16, e.g., by diffusion, scattering, etc. The light-shaping region 36 may be transmissive, as shown in
The optical element 14 shapes light that is emitted from the light emitter 16. The light-shaping region 36 shapes, e.g., diffuses, scatters, etc., light from the light emitter 16. Specifically, the light emitter 16 is aimed at the optical element 14, i.e., substantially all of the light emitted from the light emitter 16 reaches the optical element 14. As one example of shaping the light, the optical element 14 diffuses the light, i.e., spreads the light over a larger path and reduces the concentrated intensity of the light. In other words, the optical element 14 is designed to diffuse the light from the light emitter 16. As another example, the optical element 14 scatters the light, e.g., a hologram). “Unshaped light” is used herein to refer to light that is not shaped, e.g., not diffused or scattered, by the optical element 14, e.g., resulting from damage to the optical element 14. Light from the light emitter 16 may travel directly from the light emitter 16 to the optical element 14 or may interact with additional components between the light emitter 16 and the optical element 14. The shaped light from the optical element 14 may travel directly to the exit window 34 or may interact with additional components between the optical element 14 the exit window 34 before exiting the exit window 34 into the field of illumination FOI.
The optical element 14 directs the shaped light to the exit window 34 for illuminating the field of illumination FOI exterior to the Lidar system 12. In other words, the optical element 14 is designed to direct the shaped light to the exit window 34, i.e., is sized, shaped, positioned, and/or has optical characteristics to direct at least some of the shaped light to the exit window 34.
The optical element 14 may be of any suitable type that shapes and directs light from the light emitter 16 toward the exit window 34. For example, the optical element 14 may be or include a diffractive optical element 14, a diffractive diffuser, a refractive diffuser, a computer-generated hologram, a blazed grating, etc.
As set forth above, the electrical circuit 20 is across the optical element 14. In other words, components of the electrical circuit 20 extend from one end of the optical element 14 to another end of the optical element 14 along an elongated length of the optical element 14. In other words, the optical element 14 may have a depth D that is thin relative to a length L of the optical element 14 and the electrical circuit 20 may extend across the length L. The electrical circuit 20 may be across the light-shaping region 36. The electrical circuit 20, e.g., the wires 22 of
In the example shown in
The wires 22 may be, as an example, conductive metal. The wires 22 may be silver, copper, aluminum, gold, molybdenum, zing, brass, tin, steel, titanium. Alternatively, the wires 22 may be of any suitable material that is electrically conductive. The wires 22 may have high light transmissivity and/or a thickness that does not interfere with the light-shaping function of the optical element 14 (i.e., may be thin enough to avoid meaningful interference with the light-shaping function of the optical element 14).
With reference to
The two voltage dividers in the example of
Voltage is supplied at the voltage supply 38 to identify integrity of the optical element 14. The voltage may be supplied at the voltage supply 38 by the controller 18, e.g., the controller 18 may provide an instruction to supply voltage at the voltage supply 38. When the optical element 14 is intact, the voltage at the input is a result of the voltage divider. In the event the optical element 14 is damaged, at least one of the wires 22 is broken. In such an event, when voltage is supplied at the voltage supply 38, the voltage at the input 40, 42 is different than the voltage when each wire 22 is intact, thus indicating damage to the optical element 14.
With reference to
With continued reference to
The electrically-conductive layer 24 completes the electrical circuit 20 between the terminals 48. The controller 18 supplies voltage to one of the terminals 48 and voltage across the optical element 14 is detected by at least one other of the terminals 48. In the example shown in
In the example where the terminals 48 are identical, any one of the terminals 48 may be supplied with voltage and the controller 18 may cycle through a routine of supplying voltage to different ones of the terminals 48 and detecting the voltage across the optical element 14 to determine integrity of the optical element 14. In other words, the routine of supplying voltage to different ones of the terminals 48 results in a grid of current paths to increase the test area of the optical element 14 that is checked for integrity. All of the current paths of the grid are simultaneously shown in
The electrical circuit 20 is designed to break when the optical element 14 is damaged. In other words, the electrical circuit 20 is positioned, sized, shaped, has a material type, etc., that results in breakage of the electrical circuit 20 when the optical element 14 is damages. Damage includes a crack in the optical element 14 and surface damage including melting. Damage to the optical element 14 disrupts the electrical circuit 20 by disrupting and/or breaking some or all of the electrical circuit 20. As an example, with reference to
The system 10 is designed to disable operation of the light emitter 16 when the optical element 14 is damaged. Disabling the operation of the light emitter 16 may be an affirmative step, e.g., actively deciding not to power the light emitter 16, or passive, e.g., not powering the light emitter 16 in the absence of instruction to do so.
The controller 18 is programmed to control the light emitter 16 based on voltage received by the controller 18 from the electrical circuit 20. As one example, the controller 18 may be programmed to supply voltage, to the controller 18 through the electrical circuit 20 and wait for detection of a voltage from the electrical circuit 20 indicating the optical element 14 is intact. The controller 18 may be pre-programmed with a value of the voltage to be detected from the electrical circuit 20 that results from the voltage supplied at the voltage supply 38 when the electrical circuit 20 is intact. In the event the controller 18 receives the voltage from the electrical circuit 20 indicating that the electrical circuit 20 is intact, the controller 18 powers the light emitter 16. The controller 18 may be programmed to wait for the voltage indicating that the electrical circuit 20 is intact, and in the absence of such voltage, e.g., resulting from a different voltage across the electrical circuit 20 due to a break in the electrical circuit 20, the controller 18 does not power the light emitter 16. As another example, the controller 18 may be programmed to detect the voltage other than a voltage indicating that the electrical circuit 20 is intact and, in response to such a detection, decide to disable operation of the light emitter 16 (which may include not powering the light emitter 16 and/or taking an active step to disable the power emitter and/or prevent emission of light from the exit window 34). In such an example, the controller 18 may be programmed to instruct the vehicle 30, e.g., the ADAS, so that the vehicle 30 notifies a vehicle operator and/or disables the vehicle 30 or a vehicle system 10, e.g., the ADAS.
The controller 18 is in communication with the light emitter 16 and the electrical circuit 20, e.g., by wired or wireless connection capable of sending and/or receiving signals. The controller 18 may be in communication individually with the light emitter 16 and the electrical circuit 20, as shown in
The controller 18 may also be referred to as a computer. The controller 18 may be a microprocessor-based controller or field programmable gate array (FPGA), or a combination of both, implemented via circuits, chips, and/or other electronic components. In other words, the controller 18 is a physical, i.e., structural, component of the system 10. For example, the controller 18 includes a processor, memory, etc. The memory of the controller 18 may store instructions executable by the processor, i.e., processor-executable instructions, and/or may store data. The controller 18 may be in communication with a communication network of the vehicle 30 to send and/or receive instructions from the vehicle 30, e.g., components of the ADAS. Specifically, the instructions stored on the memory of the controller 18 may include instructions to perform the method 900 in
The methods 900, 1000 shown in
With reference to
In block 910, the memory may store instructions to detect voltage from the electrical circuit 20. Detecting voltage includes receiving voltage from the electrical circuit 20 or detecting the absence of voltage from the electrical circuit 20 after voltage was supplied in block 905.
The memory stores instructions to control operation of a light emitter 16 based on the level of voltage detected from the electrical circuit 20. Specifically, in decision block 915, the memory may store instructions to detect whether the optical element 14 is intact or damaged based on voltage detection. For example, as set forth above, the controller 18 may be pre-programmed, i.e., stored as instructions in the memory, with a level of the voltage to be detected from the electrical circuit 20 that results from the voltage supplied at the voltage supply 38 when the electrical circuit 20 is intact. In such an example, the memory may store instructions to wait for voltage at a level that indicates that the electrical circuit 20 is intact. As another example, the memory may store instructions to detect the voltage other than a voltage indicating that the electrical circuit 20 is intact.
In block 920, the memory may store instructions to power the light emitter 16 when the optical element 14 is intact. For example, the memory may store instructions to power the light emitter 16 when voltage detected from the electrical circuit 20 is at a level indicating that the electrical circuit 20 is intact. In other words, when no damage is detected, the memory stores instructions to power the light emitter 16 aimed at the optical element 14 to diffuse the light with the optical element 14. After powering the light emitter 16, the method 900 may be restarted. In other words, the memory may store instructions to power the light emitter 16 only if the voltage received from the electrical circuit 20 indicates that the electrical circuit 20 is intact.
In block 925, the memory may store instructions to disable operation of the light emitter 16 when the optical element 14 is damaged. Specifically, the memory may store instructions to disable operation of the light emitter 16 in response to detection of voltage from the electrical circuit 20 indicating that at least part of the electrical circuit 20 is broken. For example, the memory may store instructions to disable the light emitter 16 in the absence of voltage at a level indicating that the electrical circuit 20 is intact, e.g., resulting from a different voltage across the electrical circuit 20 due to a break in the electrical circuit 20. In such an example, the decision to disable the light emitter 16 may be made when a predetermined time period lapses after the supply of voltage to the electrical circuit 20 in block 905 without detection of voltage indicating the optical element 14 is intact. As another example, the memory may store instructions to disable the light emitter 16 in response to detecting voltage at a level that indicates the optical element 14 is damaged. As set forth above, disabling operation of the light emitter 16 may include not powering the light emitter 16 and/or taking an active step to disable the power emitter and/or prevent emission of light from the exit window 34.
With reference to
Specifically, as shown in block 1005, the memory stores instructions to supply voltage to a first terminal 48. In block 1010, the memory stores instructions to detect voltage from the first terminal 48 through at least one of the other terminals 48. In other words, the voltage is conducted through the layer 24 from the first terminal 48 to the other terminals 48. In the examples, shown in
In decision block 1015, the memory includes instructions to detect whether the optical element 14 is intact or damaged based on voltage detection. In the event the electrical circuit 20 is broken, the method 1000 proceeds to blocks 1020 and 1025 to disable operation of the light emitter 16 (as described above with reference to block 925) and potentially notify the vehicle 30 (as described above with reference to block 930).
As shown in
As another example, in the event the electrical circuit 20 is intact at block 1015, the method 1000 may skip to block 1055 and power the light emitter 16, i.e., based only on supplying voltage to the first terminal 48 and detecting voltage at the other terminals 48. In such an example, the method 1000 may be restarted at block 1005 after block 1055. In other words, the first terminal 48 is again supplied with voltage and integrity of the optical element 14 is determined based on voltage detection at the other terminals 48. As another example, another terminal 48 may be supplied with voltage and integrity of the optical element 14 is determined based on voltage detection at the other terminals 48, i.e., the method 1000 may proceed from block 1055 to block 1030 to perform steps 1030, 1035, and 1040 beginning with supplying voltage to a second terminal 48.
In block 1055, the light emitter 16 is powered (as described above with reference to block 920) based on the determination that the optical element 14 is intact.
The powering of the light emitter 16 in blocks 920 and 1055 results in emission of light from the light emitter 16 to the optical element 14, which diffuses the light and directs the light through the exit window 34 to illuminate the scene. The memory stores instructions to detect a range of an object illuminated by the light diffused by the optical element 14. The methods 900, 1000 are repeated before each time the light emitter 16 is powered so that the optical element 14 is tested before each light emission.
Throughout this disclosure, use of “in response to” and “upon determining” indicates a causal relationship, not merely a temporal relationship. The numerical adjectives such as “first,” “second,” etc. are used herein as identifiers and do not indicate order, importance, or relative arrangement. The disclosure has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described.