CASE ECAS (Automotive Active Electronic Controlled Air Suspension ) System Architecture
After years of R&D and application practice, CASE has developed a mature ECAS system and multiple patents had been applied. CASE ECAS technology (ECAS system development / calibration and its calidation, control strategy / algorithm and its chip, ECAS system core components development / mass production and validation) is applicable to a variety of vehicles in different of duty and suspension type, including sedan , SUV, MPV, light/heavy commercial vehicle, ambulance, military armored vehicle, etc. CASE ECAS system has been deliver to OEMs since 2016.
To cop with the diversity of market in performance vehicle, CASE developed Magnetorheological (MR) damper and became the world's second supplier of OEM MR damper. In the present market, MR Damper is mainly used in Ferrari, Audi, Chevrolet Corvette, Cadillac, Land Rover, Acura and other high performance cars.
CASE ECAS system is scalable. In addition to Full ECAS system, and of light commercial vehicles to achieve low cost, CASE also developed ECS and EAS which is simplified configuration with lower cost.
• ECS: Dynamic variable damping system based on traditional coil spring, without air spring system.
• EAS: Electronically controlled air spring system only without active damper system. EAS is able to achieve vehicle leveling adjustment. Some vehicle also consider EAS for rear suspension only.
CASE Patents for ECAS system and core components
• ZL2010 2 0202275.0 is the patent for CASE in the mechanical design of air spring in macpheran suspension.
• ZL 2016 2 0023965.7 is the patent for CASE in MR damper design
• The invention patent of "a MR liquid process " is under approval process
• The invention patent of " a Cycling Nitrogen System for Air Suspension " is under approval process
ECAS Control Technology - the leading CASE proprietary "Property Separation Method" full digital control technology
ECAS control strategy and algorithm are the core of ECAS system technology. CASE company unique "Property Separation Method" full digital control technology, to solve the peer generally based on the traditional "Skyhook Principle" and the ECAS system used by the traditional control method can not solve the problem, from the road vibration excitation filter more thoroughly, while making the body more stable, the system structure is more simple, reliable, lower cost.
CASE ECAS control technology main points are:
• Using Integral prediction method to analyze the body motion state properties, isolate the self-oscillating and forced oscillatory vectors, and use the differential control method to control the body more accurately, ie autonomous Σ-Δ technique
• Use a specific matrix association algorithm to filter and reduce the high frequency, so that the strong reflection of hard road driving comfort and handling to further improve
• The new combination correlation detection control method reduces the number of sensors, simplifies the system structure, increases reliability, and reduces costs
ECAS Control Technology - Control Points based on "Property Separation Method"
The control points of "Property Separation Method" include methods of target approaching, feedback, convergence forward, reverse vibration and it's combinations. It can realize four driving modes as below in one vehicle effectively and obviously:
• Comfort Mode： soft and stable, suitable in comprehensive road condition
• Sports Mode： hard and strong road feedback. Suitable for flat and curve road for driving fun
• Off-road Mode： relatively soft and very stable for low frequency wave road and high way
• Soft Mode: Very soft and suitable to drive in gravel road
The vehicle could be set into Auto Mode which will allow vehicle to switch mode between Comfort/Sports/Off-Road/Soft modes based on vehicle speed.