Aggressive drivers are known road hazards, causing one third of all traffic crashes. But inattentive or distracted driving is becoming more of a problem as people "multitask" by talking on the phone, texting or checking messages, eating, or even watching TV as they drive.
Distractions, like talking on the phone or eating, make a driver less able to see potential problems and properly react to them. It's not just teen drivers who are at fault: People who have been driving for a while can get overconfident in their driving abilities and let their driving skills get sloppy. All drivers need to remind themselves to stay focused.
Watch out for the other guy. Part of staying in control is being aware of other drivers and roadway users around you (and what they may suddenly do) so you're less likely to be caught off guard. For example, if a car speeds past you on the highway but there's not much space between the car and a slow-moving truck in the same lane, it's a pretty sure bet the driver will try to pull into your lane directly in front of you. Anticipating what another driver might do and making the appropriate adjustment helps reduce your risk.
When you drive defensively, you're aware and ready for whatever happens. You are cautious, yet ready to take action and not put your fate in the hands of other drivers. According to the U.S. Department of Transportation, 90% of all crashes are attributed to driver error.
If you're interested in taking a defensive driving course to help sharpen your driving knowledge and skills, contact your local AAA or your state's Department of Motor Vehicles (DMV). Many states keep a list of approved defensive driving course providers, and lots of these offer online programs. In some states, you may be eligible for insurance premium discounts, "positive" safe driving points, or other benefits. These courses do cost money, but it's worth the investment to be a smarter, safer driver.
These lifesaving systems are key to the success of ADAS applications. They incorporate the latest interface standards and run multiple vision-based algorithms to support real-time multimedia, vision coprocessing, and sensor fusion subsystems.
The implementation of cameras in the vehicle involves a new AI function that uses sensor fusion to identify and process objects. Sensor fusion, similar to how the human brain process information, combines large amounts of data with the help of image recognition software, ultrasound sensors, lidar, and radar. This technology can physically respond faster than a human driver ever could. It can analyze streaming video in real time, recognize what the video shows, and determine how to react to it.
Car navigation systems provide on-screen instructions and voice prompts to help drivers follow a route while concentrating on the road. Some navigation systems can display exact traffic data, and if necessary, plan a new route to avoid traffic jams. Advanced systems may even offer heads-up displays to reduce driver distraction.
Night vision systems enable drivers to see things that would otherwise be difficult or impossible to see at night. There are two categories of night vision implementations: Active night vision systems project infrared light, and passive systems rely on the thermal energy that comes from cars, animals, and other objects.
Automatic emergency braking uses sensors to detect whether the driver is in the process of hitting another vehicle or other objects on the road. This application can measure the distance of nearby traffic and alert the driver to any danger. Some emergency braking systems can take preventive safety measures such as tightening seat belts, reducing speed, and engaging adaptive steering to avoid a collision.
This relatively new ADAS feature supports the vehicle in counteracting strong crosswinds. The sensors in this system can detect strong pressure acting on the vehicle while driving and apply brakes to the wheels affected by crosswind disturbance.
This hot new 5G ADAS feature provides communication between the vehicle and other vehicles or pedestrians with increased reliability and lower latency, generally referred to as V2X. Today, millions of vehicles connect to cellular networks for real-time navigation. This application will enhance existing methods and the cellular network to improve situational awareness, control or suggest speed adjustments to account for traffic congestion, and provide real-time updates to GPS maps. V2X is essential to support over-the-air software updates for the now-extensive range of software-driven systems in cars, from map updates to bug fixes to security updates and more.
The opportunity to reduce car accidents is making ADAS even more critical. Automatic emergency braking, pedestrian detection, surround view, parking assist, driver drowsiness detection, and gaze detection are among the many ADAS applications that assist drivers with safety-critical functionality to reduce car accidents and save lives.
The adoption of 64-bit processors, neural networks and AI accelerators to handle the high volume of data requires the latest semiconductor features, semiconductor process technologies, and interconnecting technologies to support ADAS capabilities.
Our solutions can help automatically detect third-party components in source code and binaries, prioritize security vulnerabilities and licenses in use, and find critical defects and weaknesses in code during development. We also support the design phases of the development life cycle by identifying the design flaws, control defects, and asset vulnerabilities that define the overall risk to a system.
Our approach to system security in the automotive industry is grounded in the fundamentals of technology risk management. Synopsys supports the distinct needs of the automotive industry by performing critical activities for automotive organizations, including:
A basic fully differential voltage-feedback ADC driver is shown in Figure 1. Two differences from a traditional op-amp feedback circuit can be seen. The differential ADC driver has an additional output terminal (VON) and an additional input terminal (VOCM). These provide great flexibility when interfacing signals to ADCs that have differential inputs.
The analysis of differential ADC drivers is considerably more complex than that of traditional op amps. To simplify the algebra, it is expedient to define two feedback factors, β1 and β2, as given in Equation 5 and Equation 6.
Output balance, an important performance metric for differential ADC drivers, has two components: amplitude balance and phase balance. Amplitude balance is a measure of how closely the two outputs are matched in amplitude; in an ideal amplifier they are exactly matched. Output phase balance is a measure of how close the phase difference between the two outputs is to 180°. Any imbalance in output amplitude or phase produces an undesirable common-mode component in the output. The output balance error (Equation 10) is the log ratio of the output common-mode voltage produced by a differential input signal to the output differential-mode voltage produced by the same input signal, expressed in dB.
ADC drivers are frequently used in systems that process high-speed signals. Devices separated by more than a small fraction of a signal wavelength must be connected by electrical transmission lines with controlled impedance to avoid losing signal integrity. Optimum performance is achieved when a transmission line is terminated at both ends in its characteristic impedance. The driver is generally placed close to the ADC, so controlled-impedance connections are not required between them; but the incoming signal connection to the ADC driver input is often long enough to require a controlled-impedance connection, terminated in the proper resistance.
The input resistance of the ADC driver, whether differential or single-ended, must be greater than or equal to the desired termination resistance, so that a termination resistor, RT, can be added in parallel with the amplifier input to achieve the required resistance. All ADC drivers in the examples considered here are designed to have balanced feedback ratios, as shown in Figure 2.
When input coupling is optional, it is worth noting that ADC drivers with ac-coupled inputs dissipate less power than similar drivers with dc-coupled inputs, since no dc common-mode current flows in either feedback loop.
Table 2 summarizes the most common ADC driver input-stage types used with various input-coupling and power-supply combinations. However, these choices may not always be the best; each system should be analyzed on a case-by-case basis.
To maximize the dynamic range of an ADC, it should be driven to its full input range. But care is needed: drive the ADC too hard and risk damaging the input, not hard enough and resolution is lost. Driving the ADC to its full input range does not mean that the amplifier output has to swing to its full range. A major benefit of differential outputs is that each output only has to swing half as much as a traditional single-ended output. The driver outputs can stay away from the supply rails, allowing decreased distortion. This is not the case for single-ended drivers, however. As the output voltage of the driver approaches the rail, the amplifier loses linearity and introduces distortion.
For applications where every last millivolt of output voltage is required, Table 1 shows that quite a few ADC drivers have rail-to-rail outputs, with typical headroom ranging from a few millivolts to a few hundred millivolts, depending on the load.
The total output noise voltage density, vno, dm, is calculated by computing the root sum square of these components. Entering the equations into a spreadsheet is the best way to calculate the total output noise voltage density. The new ADI Diff Amp Calculator (Ref. 3), which will quickly calculate noise, gain, and other differential ADC driver behavior, is also available on the Analog Devices website. 2b1af7f3a8