Electric vehicle manufacturer Tesla has filed a patent for an automated system capable of detecting and cleaning debris from glass on vehicles and solar panels using pulsed laser beams.
The patent covers a system that includes an optics assembly that emits a laser beam, circuitry that detects debris on the glass, and control circuitry that calibrates the parameters of the laser beam based on the amount of debris detected.
In addition to the windscreen of vehicles, where accumulated dirt can occlude the line-of-sight of a human driver during a journey, dirt can also accumulate on the lenses of cameras mounted on a vehicle for autonomous driving, which could lead to errors in image acquisition and ultimately the performance of the autonomous driving system.
A windshield and a bonnet portion of a vehicle configured with the proposed laser cleaning apparatus. (Image: Tesla)
For solar panels, dirt that accumulates over a period of time may cause a decrease in their power capture efficiency, which may translate into lower power output to the homes, offices, transport systems, and other facilities that depend on the electricity provided by the solar panels.
A solar photovoltaic facility equipped with the proposed laser cleaning apparatus. (Image: Tesla)
Tesla explained in the patent filing that conventionally, automated solutions for cleaning glass in a vehicle or a photovoltaic assembly rely on either a physical contact of a robotic brush with the glass, or usage of sophisticated chemical solutions that are sprayed over the glass. Although such automated solutions may successfully clean the glass, the preparations involved can take a significant amount of time, with the cleaning and drying period also adding to overall time required. Additionally, the usage of chemical solutions might be unsuitable for certain glass articles installed in the electronic devices of vehicles (for example cameras and dashboards) as they could potentially turn defective with the application of such chemicals.
The proposed laser cleaning system could therefore be expected to address these issues if developed.
According to the patent filing:
- Emitted laser beams may require beamforming and steering at specific horizontal and vertical sweep angles, to effectively remove the debris.
- The beam optics assembly may include different optical components (for example, galvanic mirrors, micro mirror arrays, laser windows, specialized lenses, and actuators) to steer and execute beamforming of the laser beam.
- The cleaning system may include multiple beamforming assemblies for vehicle windshields, windows, and camera lenses that use light from a single laser source.
- Alternatively, the cleaning system may include multiple laser sources that generate different laser beams for different beamforming assemblies.
- A laser barrier coating (for example, indium tin oxide) may be used as a protective coating on or layered within the glass to facilitate absorption/reflection of a portion of energy of the laser beam.
- The cleaning system may not be limited to cleaning glass on a vehicle, but also ceramic tiles or metal panels.
- The cleaning apparatus may include a cooling system that could be installed in the front or back trunk of the vehicle, in order to remove heat as a result of the operations of the laser(s).
- For solar panels, a moving bar (see item 316 in the above image) containing the debris detection circuitry, the laser emitter, and the beam optics assembly may be used to slide along the length of a solar panel to detect and remove debris.
- Alternatively, laser pods (see item 318A/B in the above image) containing all the components of the cleaning apparatus may also be used to detect and remove debris from solar panels.
