Apple patent suggests installing sensors under self-driving cars

According to foreign media reports, almost all drivers need to rely on the car speedometer to understand the driving speed and the overall feeling of the car's movement, so as to know whether they should pay more attention. Drivers handle differently when driving on wet or icy roads than on dry roads. Although drivers may want the vehicle to drive normally in a specific way, in this case, in order to achieve the desired effect, they may have to turn the steering wheel excessively. Coupled with variable factors such as tire flexibility, tire size, temperature, pressure and vehicle load, driving becomes an even more difficult task.

Changing weather and road conditions are also a problem for self-driving car systems, which are equipped with a lot of safety systems to ensure that people in the car are not harmed. The current systems used to determine the relative speed of the road include wheel encoders, inertial sensors and GPS signal detection, but Apple believes that this is far from enough. Inertial sensors are susceptible to noisy accelerometers and cannot accurately measure speed; and due to interference from the natural environment and technical means, global national satellite systems such as GPS are also unreliable.

On April 2, local time, the US Patent and Trademark Office granted Apple a patent called "Instruments and methods for measuring slip and speed", which aims to solve the above problems in two different ways and use more sensors to ensure that the car can drive smoothly.

The first method is that Apple suggests installing two sensors at the bottom of the car to scan the road surface or ground. By measuring the reflected electromagnetic waves from the two sensors, the system can generate a pair of "Doppler slopes" to determine the speed and angle of the vehicle's movement.

The first data point can provide suggestions on how fast the car should be traveling, while the angle data can tell the autonomous driving system when some actions are beyond the system's expectations, such as when the car is turning on an icy road but the sensors indicate that the angle of the turn is not enough. This data can then be compared with data from inertial sensors and GPS to ensure accuracy.

The second method is that Apple recommends using multiple sets of sensors that point not only at the road surface, but also at an angle in front of the car, rather than vertically. In addition to capturing speed and slip in a larger measurement area, the second method can also generate longitudinal and lateral sensor speed data. The collected data is then compared with data from other sensors and ultimately used as the basis for the autonomous driving system to make decisions.

Although the release of Apple's full car seems to be getting further and further away, there are reports suggesting that Apple may be developing a car, as Apple recently hired Michael Schwekutsch, vice president of engineering at Tesla, to study the car's powertrain. Other related patents introduced by Apple include: sensors that can capture driver's point of interest data, use gestures to control a moving self-driving car, use augmented reality to display the road ahead and other information on the windshield, communicate with other self-driving systems across vehicles, use a mobile device to summon a self-driving car, and pay for the fare, etc.