Full-stack thinking of Gates electronic suspension system after years of deep cultivation in the field of automobile chassis

The first prediction is that the control software will be centralized and integrated into the chassis domain controller or the vehicle's central controller VCU, and the controller will have AI self-learning capabilities.

The second prediction is that high-definition cameras, the coordination of vehicle-road-cloud and high-precision maps will be able to identify road conditions in advance and control the chassis. The current trend is how to effectively control at low cost and predict road conditions in advance.

The third predicted direction is the linkage within the chassis domain, such as controlling steering, braking, etc., which can achieve highly sensitive steering, braking and other dynamic controls.

The fourth prediction is that the entire suspension system will be closed-loop and produce high-precision system control. The chassis lifting speed will be greatly improved, and the lifting speed will be increased by 10 centimeters per second in the next few years.

The fifth prediction is that the voltage of the whole vehicle will increase from the traditional 12V and 24V to the hybrid 48V, and even the high-voltage system of 400V and 800V, and even now there is an ultra-high voltage system. Gates Electronics is currently involved in the research and development of the 950V ultra-high voltage system project, and there may be a 1000V system in the future.

The sixth prediction refers to the comprehensive application of safety redundancy technology, including current functional safety ISO26262, expected safety ISO21448, and related network information security, which is also a challenge to the entire chassis suspension system and electronic control system.

Gates' product cases in chassis suspension electronic control systems

Gates Electronics currently has two mainstream products. The first is a continuously damped adjustable suspension electronic control system. The structure of the entire system is shown in the figure below. The core is still the entire electronic control ECU, which obtains some information on the VCU through CAN communication, such as the driver's intention, whether there is a pedal signal, whether there is pedal pressure, including some vehicle corners, and combines with sensors on the body, such as body acceleration sensors, wheel vertical acceleration sensors, and some OEMs prefer to use body height sensors. The specific number, including the type of sensor used, is related to cost and algorithm. Each OEM has its own preferences and demands.

By combining these signals, the corresponding shock absorbers are controlled, four in front, back, left and right, and the Gates Electronics unique damping force smooth control algorithm is used to improve the comfort of the whole vehicle and the stability of the control. The characteristics of Gates' current products are that the protection level is still relatively high, reaching the level of IP54. EMC can reach the level of Cispr25 and Level5, and the weight is relatively light, within 500 grams, which meets the needs of lightweight . In the future, it may be reduced to 400 grams. The entire software architecture adopts the Autosar architecture, which is also in line with the current mainstream OTA, UDS and other corresponding online cloud upgrade services. The hardware adopts a platform design. In addition to system status management, fault detection, degradation, and temperature compensation, the corresponding control mode can also control the impact residual vibration, prevent the whole stroke, and control the acceleration and deceleration according to the vehicle speed and road surface. At the same time, it prevents tilting and diving, controls the driving performance, estimates the spring mass, unsprung mass, and controls the damping of the unsprung mass. Finally, there is energy-saving control, which meets the current requirements of energy conservation and emission reduction.

The composition and characteristics of the Gates air suspension electronic control system are the same as those of CDC. The core of the entire system is still the controller, of course, it still communicates through CAN/CANFD, and also obtains the corresponding signal from the VCU of the whole vehicle, and then combines some sensors on the vehicle, by allocating the gas in the pressurized gas, and by controlling the air pump. The air pump is currently directed to a brushless motor, and is distributed to the front air spring and the rear air spring through the air pump, so as to provide the whole vehicle with a multi-mode strategy, such as the comfort strategy, personalized strategy, and off-road strategy I mentioned earlier. The protection level of this product made by Gates Electronics is very high, achieving the protection level of IP6K9K. It currently also adopts the Autosar architecture. Gates Electronics has in-depth cooperation with mainstream Autosar at home and abroad. Functional safety Gates Electronics is also currently considering the use of ASIL-B and D redundant designs. At present, in terms of chips, Gates Electronics and domestic chip design companies have cutting-edge pre-research (based on RISCV architecture) and are actively deploying their use.

At the same time, in addition to being compatible with CDC control, there are also some vehicle height control algorithms, speed adjustment algorithms, load identification strategies, vehicle height disable strategies, and full-stroke prevention control. At the same time, it can protect the brushless motor of the air pump and detect the pressure of the air valve and the pressure of the accumulator. The following figure is the architecture of the controller.

Gates Electronics' exploration of chassis suspension innovation scenarios

The first scenario explored is on the battery-integrated chassis. Now, when CTC, CTB, and skateboard chassis, which are battery-based battery structural parts, are installed on vehicles, the vehicle's front and rear tilt angles are relatively small and its terrain traversal ability is relatively weak. Gates' current solution is to use air suspension as the main body to implement the vehicle's obstacle avoidance system. The trend is to integrate high-definition cameras. Currently, Gates Electronics uses TOF as a low-cost solution. Gates has also applied for some patents for data collection equipment, which can predict vehicle obstacles in advance, reduce chassis damage, and reduce after-sales maintenance rates.

The second application scenario is Robotaxi. Gates believes that the first application scenario of the intelligent chassis is the unmanned vehicle Robotaxi. The complex environment does not allow for high-degree-of-freedom parking and all-terrain unlocking. This direction is the focus of Gates Electronics. This requires the entire system to be linked and requires fusion control in the three directions of XYZ. It mainly uses air suspension, wire-controlled steering, and wheel hub motors to achieve multi-degree-of-freedom unlocking for parking, such as oblique shift mode, double Ackerman, lateral shift, self-drive, and self-rotation. In the case of narrow terrain, it can even achieve parking in special scenarios where two wheels are lifted up on mountain roads and two wheels are driving on the road. The parking environment is relatively convenient.

The third application scenario is in the smart cockpit. As the second space for human beings, the emerging smart cockpit with driverless shared cars as the main body should give more experience to the passengers in the back row and even the corresponding members. The current solution of Gates Electronics is also based on air suspension, adding a vehicle body sense, combined with the seats of the smart cockpit, including fans and blowers, to achieve a 4D experience effect through vibration control, and even reach 5D, adding some body sense of racing sports games, making the vehicle more entertaining and giving it some newer experience.

The last scenario is the smart charging scenario. For new energy vehicles and driverless cars, the current charging mode is still to go to the charging station for manual charging. Since there are no people in the vehicles, can charging be unmanned? If there is a fully decoupled smart charging that frees your hands, it will be very meaningful to reduce labor costs in the future and improve the efficiency of other work. The current solution is also based on air suspension as the execution body, combined with camera data collection devices inside and outside the car, which can be linked with the charging device. The charging device needs to be calibrated, and the corresponding charging guidance is finally made according to the relationship between data, vehicle height, and position to achieve corresponding fully automatic charging.