Moving beyond normal height-adjustable air suspension and adaptive damping, this new Tesla system incorporates actuators to directly control wheel motion.
Tesla's next-generation active suspension system has been revealed in a new patent, and it represents a leap forward for this company's suspension technology. CarBuzz found the details at the World Intellectual Patent Office, which shows that the new suspension will be a lot more sophisticated than the current air suspension design.
Many luxury manufacturers have since enhanced their adaptive suspension systems with active wheel position control. Rather than merely raising or lowering the suspension or changing the spring- and damper rates according to preset values, these new-generation active suspension systems are capable of continuously moving the wheels to their most advantageous positions to best compensate for road surface irregularities.
This new Tesla patent aims to do the same by dynamically altering the suspension strut length according to current and expected road surface conditions. An actuator motor is located in the top strut mount assembly, which uses a belt drive assembly to turn a threaded screw connected to the strut shaft. This effectively alters the strut shaft length by moving the strut's upper mounting point up or down, which enables active control over the wheel's position.
Such electrically-actuated wheel position control systems have been mooted for decades, but their limitation has always been that they need a lot of electrical power to function. But, while a Tesla's battery system has plenty of power to make such systems work, the electric motors that power the adjustable struts are helped along by series-mounted passive springs and dampers to reduce some of the load and frictional losses induced by such a system.
As with all new technological advancements, the control system is a key component in this new suspension design. System inputs, in this case, include vibration sensors, accelerometers, wheel position sensors, and pitch and roll sensors, while Tesla's clever anonymized fleet data collection system will likely also provide some information regarding road conditions.
It is also likely that camera systems (of which Teslas already have many) will scan the surface ahead to help predict optimal wheel positions and other suspension settings as it moves along the road. This could operate in a similar fashion to the proactive E-Active body control system available in the Mercedes-Benz S-Class.
In addition to ride height management and suspension leveling, this will allow the new suspension control system to detect potholes, ridges, and ruts in advance and retract the affected wheel into its housing in response, thus reducing the intensity of the impact between the wheel and the road irregularities. Dynamically-adjustable strut shaft lengths will also enable the vehicle to counteract body roll without upsetting the spring- and damper rates and eliminate pitch and squat while accelerating and braking.
The current Tesla Model S and Model X employ a fairly conventional height-adjustable air suspension system with adaptive spring- and damper rates. This endows the two most expensive (and oldest) Tesla models with variable ride height and suspension stiffness and was on par with Tesla's competitors when these two models were released in 2012 and 2015, respectively.
Source Credits: US Patent and Trademark Office
Keyword: Tesla's Future Active Suspension Tech Revealed In New Patent