Polyvinyl butyral, also known as PVB, is a remarkable polymer that finds its place in a vast array of applications. It can be discovered in various paints, coatings, and adhesives, showcasing its versatility. With its exceptional properties, PVB acts as a binder for coatings, primers, metal powder, ceramics, and even as an interlayer film in laminated safety glass.

Structure of PVB (Polyvinyl Butyral)
Polyvinyl butyral is synthesized through a chemical process where there is acetylation of polyvinyl alcohol with butyraldehyde. This creates butanal – part of the polyvinyl acetal family. This chemical is derived from the hydrolysis of polyvinyl acetate. Some acetyl groups remain intact, influencing the substance’s solubility in other chemicals. A low degree of acetylation results in high water solubility, while a high degree promotes its ability to dissolve in alcohol. In the case of polyvinyl butyral interlayers for laminated glass, complete functionalization is undesirable, as unreacted hydroxyl groups facilitate adhesion to glass surfaces.

Properties of PVB
Chemical (CAS) Number: CAS No. 63148-65-2 – PVB is a synthetic polymer. This makes it part of the polyvinyl acetal family. PVB is manufactured and processed using thermoplastic methods. Depending on acetylation and molecular weight, PVB can be very durable and used in many industries. Water absorption depends on acetylation. PVB is like organic solvents in that it dissolves in nearly all organic solvents. They can also be heat sealed at 120+ degrees Celsius.

Benefits of PVB (Polyvinyl Butyral)

This chemical has become a popular choice as a binder and hot-melt adhesive in various applications.

• Excellent adhesive and film-forming properties
• High water resistance
• Optical clarity
• High bond strength
• Good elasticity
• Exceptional processability

Industries

• Primers and coatings
• Printing inks for packaging
• Films for laminated safety glass
• Binders for ceramics and metal powder
• Adhesives
• Coatings for retro-reflective traffic signs and road markings
• Many other special applications.

PVB with its ability to bind glass panels together makes it a crucial component in laminated safety glass (such as windshields and sunroof glass), where it acts as a hot-melt adhesive. Due to its remarkable tensile strength and ability to bind glass splinters, polyvinyl butyral is commonly employed as an interlayer film in laminated safety glass. For instance, the polymer layer between the glass panels of a windshield is predominantly made of polyvinyl butyral. Its exceptional adhesion to glass makes it perfect for bonding glass panels together or to other materials. Polyvinyl butyral can be applied as a solution or in a molten state. The manufacturing process of laminated glass involves bonding sheets of glass using polyvinyl butyral resin, plasticizers, and other substances under high heat and pressure.

PVB for coatings, primers and resins (Polyvinyl Butyral)
It can be used for binders in inks, paints, and primers. PVB is an incredible adhesion and bonding properties. PVB offers optical clarity, film forming and anti-corrosion properties including being used for stove enamel and glazers.

Advanced Driver Assistance Systems (ADAS) are a combination of sensors and cameras that are crucial components in modern vehicles. These sensors utilize various technologies, such as radar, lidar, and cameras, to gather data about the vehicle’s surroundings. By continuously monitoring the environment, ADAS sensors provide valuable information to assist drivers in making safer and more informed decisions on the road. They enable features like adaptive cruise control, lane departure warning, and automatic emergency braking. With their ability to detect potential hazards and alert drivers, ADAS sensors play a vital role in enhancing vehicle safety and reducing the risk of accidents.

Each ADAS sensor is unique in gathering data to comb through and be used. Let’s learn about the inner workings of each component and evaluate their advantages and disadvantages. The ADAS system includes:

• Cameras
• Radar
• Lidar (light detection and ranging)
• Sonar/ultrasonic
• Future technology

Different Types of ADAS Sensors
Cameras – These type of sensors are used for multiple functions. They are very good at detecting objects on the road, be it cars, cyclists, or pedestrians. They are the neural network of ADAS systems, providing the primary sensory input for most automaker ADAS systems. Like eyeballs, cameras act as the eyes of the vehicle. Without them the vehicle would be incapacitated.

ADAS Camera Sensors VS Automotive Dash Cameras
ADAS camera sensors possess high-powered microprocessors and intricate data processing algorithms, setting them apart from their brethren. These components convert the ever-changing analog image captured by the camera into digital data, which fuels a plethora of safety systems. The Subaru EyeSight ADAS suite is an example of some of the most modern ADAS systems. There are two twin forward-mounted cameras collecting vast amounts of data to enhance the accuracy of its forward sensing data.

360 Degree Panoramic View Cameras
Some cutting-edge vehicles boast 360-degree cameras, an assemblage of tiny cameras strategically positioned at the front, rear, and sides of the car. These cameras provide an overhead view of the vehicle’s immediate surroundings, enabling features such as parking assistance and lane change warnings. Take, for instance, the 2022 Hyundai Sonata, which boasts the remarkable Surround View Monitor on its Limited Trim. Equipped with four cameras, one on each side mirror and two at the rear, the Sonata presents a split-screen image that displays all angles simultaneously on the infotainment touchscreen. Prepare to be captivated by the wonders of 360-degree and surround view cameras, for their capabilities are nothing short of extraordinary.

Radar Sensors
Radar sensors play a pivotal role in collision-avoidance systems. These sensors emit radio waves that bounce off objects and return to the sensor, allowing the system to calculate the object’s distance. A computer then processes this information, creating a three-dimensional image of the surrounding area. Their ability to detect objects at a distance and in adverse weather conditions, such as rain or fog, renders them indispensable in the realm of ADAS. Prepare to be enthralled by the wonders of radar sensors, for their capabilities are nothing short of extraordinary.

Radar sensors find their purpose in a multitude of ADAS applications, including:

• Adaptive cruise control
• Blind-spot monitoring
• Forward collision warning
• Pedestrian detection
• Future technology

Lidar Sensors
Lasers are integrated in with the windshield and auto glass to measure distances. This technology possess an unparalleled precision and capability to detect even the minutest of objects. These sensors can identify people and irregularities in the terrain, employing pulsed lasers to detect nearby objects. Combining the advantages of both cameras and radar, lidar ADAS sensors offer unparalleled accuracy and detail, boasting an impressive range. Prepare to be astounded by the wonders of lidar sensors, for their capabilities are truly extraordinary.

GPS & GNSS Sensors
Global Navigation Satellite System (GNSS) is a mind blowing technology turns a paper road map into a real life 3-D model. Comprising over 30 Earth-orbiting satellites, GNSS transmits precise time and position data incessantly. When a receiver captures signals from at least four of these satellites, it can triangulate its position, with the accuracy increasing as more satellites come into play. ADAS systems rely on GNSS sensors to determine the vehicle’s position and orientation relative to its surroundings.

The integration of GNSS sensors empowers vehicles to make informed decisions based on their location and the surrounding environment. Furthermore, this ADAS feature paves the way for the future of fully autonomous cars, as GNSS receivers utilize various frequencies, constellations, and cutting-edge technologies to provide unparalleled positioning and sensor integration.

Pros Cons of GPS & GNSS

Pros
Simplicity: Implementing cutting-edge technologies such as lidar and machine learning in ADAS vehicles can be quite challenging. In contrast, integrating GNSS sensors into the system is relatively simple. The ability to combine multiple devices into a single sensing environment is crucial for seamless operation.
Affordability: The long commercial life of GPS has contributed to its affordability. Over time, GPS has become a common technology, allowing businesses to invest in developing low-cost variants. While researchers are still working on reducing the cost of GPS sensors, their current affordability is a significant advantage.
Separation: Unlike other technologies, GPS does not rely on a vehicle’s immediate vicinity for operation. Instead, it is based on the movement of satellites. This separation from the vehicle’s location makes GPS an excellent choice for data authentication, ensuring accurate and reliable information.

Cons
Inaccuracy: While GNSS receivers can pinpoint their location with precision, this accuracy may not be sufficient for primary navigation in cars. If even one satellite is out of position, the location data provided by the GNSS sensor can be completely thrown off. To mitigate this issue, GNSS receivers must rely on data from multiple satellites.
Unreliability: For GPS receivers to function with the desired precision, they require a line of sight to at least four satellites. This requirement makes GNSS receivers less suitable for urban environments, where tall buildings and other obstacles can obstruct the line of sight.
Dependency on Mapping: GNSS sensors heavily rely on mapping data to function effectively. If the GPS receivers fail to receive signals from the satellites, they become useless. Additionally, the mapping data must be regularly updated for the system to work accurately, adding to the overall cost of an ADAS system.

Ultrasonic & Sonar Sensors
Ultrasonic sensors are primarily used in parking assist and self-parking systems. These sensors, positioned inside the front and/or rear bumper covers. They use sound waves, like sonar, it emits these frequencies to detect people and objects near the vehicle. They also help determine if the vehicle is properly positioned within a parking space, providing warnings or adjusting the position if necessary.

Sonar sensors play a crucial role in air-bag control systems. When the car’s airbags are deployed, these sensors emit ultrasound bursts to determine the exact location of the occupant, aiding in the deployment of airbags for maximum safety.

ADAS Sensor Fusion
The neural network is real! By collecting all the data from the ADAS system, we get what we call sensor fusion. This involves combining data from various sensors, including radar, lidar, cameras, and more, to create a unified model. By fusing the finest data from each sensor, while disregarding irrelevant information, vehicles equipped with sensor fusion systems can enhance ADAS features such as cross-traffic aid and obstacle avoidance.

Cameras are excellent at detecting roads, reading signs, and identifying other vehicles

• Lidar solutions excel at accurately determining the car’s position
• Radars are better suited for measuring speed.
• Sensor fusion allows for the integration of these distinct capabilities, providing a 360-degree view of the vehicle’s environment.

ADAS Calibration
ADAS sensor technology is undoubtedly exciting, but it also requires regular calibration to ensure optimal performance. Calibration becomes necessary after events such as windshield replacement, fender benders, collisions, adjacent repair work, or changes in wheel alignment. Whenever a sensor is moved from its original position, it must be recalibrated by a professional in a specially designed environment.

Failure to calibrate ADAS sensors can result in inoperable or incorrectly functioning systems. This can lead to warning alerts, braking, or steering actions occurring too soon or too late, compromising the safety of the vehicle and its occupants. Car ADAS specializes in providing turnkey ADAS calibration center solutions, including training and support, to ensure accurate and reliable sensor calibration.