Taking another look at a technology once introduced by Bose
My January 2005 Technologue ranks as one of my most memorable. It featured a daring new active suspension that employed electromagnetic rams (like the ones that probably ding your doorbell), scaled and powered up sufficiently to enable a Lexus LS 400 to leap over a 2-by-6 lying across the road. At the time of that impressive demo the Bose Corporation had been quietly working on the concept for 24 years.
Ten years later the technology finally came to production … scaled down by a fifth as a vibration-canceling seat suspension for long-haul trucks. Then in November 2017 came word that a Boston-area automotive tech firm called ClearMotion had purchased the rights from Bose for all its ride-related technology. Might Amar Bose’s lifelong dream of cars riding on electrons be poised to come true?
Not exactly. But ClearMotion’s goal is the same. Founder and CEO Shakeel Avadhany believes the demand for smooth ride quality is about to spike. That’s because, as I noted last June, when autonomy makes everyone a passenger, staring at smartphones (or one another) and not looking out the windows will make car sickness a bigger problem—one that diminishes as ride quality improves.
Here’s how ClearMotion’s system works: A small turbine pump, power pack, and control electronics module gloms on to a conventional monotube or twin-tube damper at each suspension corner. This 48-volt electric pump pressurizes one side or the other of the damper piston and drives the wheel down into a pothole or pulls it up over a bump. As was the case with the Bose suspension, the pump then regenerates much of the electricity it just expended as gravity, or spring energy drives the fluid back through it during rebound. Hence net power consumption from the vehicle remains modest, though ClearMotion isn’t talking specifics yet.
Four driving modes are programmed: performance mode (max pitch and roll resistance), compromise mode (smooth ride with moderate pitch/roll management), magic-carpet ride, and one that mimics total passive shocks (to demonstrate how bad old cars were). Avadhany claims his system can effectively counteract up to 15 road-surface irregularities per second and can actively manage wheel motions throughout a vehicle’s entire range of suspension motion. The dampers retain passive damping capabilities for extreme inputs that exceed the system’s cancelation abilities.
The system has been under development for five years, and dozens of prototype vehicles are undergoing durability and extreme-weather testing at sites around the world. It will enter production in two years on a (human-driven) electric vehicle from an as-yet-unnamed company—probably one with a forward-thinking boss enamored of disruptive technologies.
ClearMotion suspensions will effectively “fingerprint the road surface,” measuring irregularities and sharing the data to plot the smoothest course between bumps.
The initial application of this so-called “proactive suspension” will not employ forward cameras to directly measure the road surface. Instead it will rely on extremely quick accelerometer sensing of wheel motions and fast-reacting (5 milliseconds) controls. Adding road sensing will improve system performance.
Another intriguing aspect of the system: Working with partner Bridgestone Tire, ClearMotion suspensions will effectively “fingerprint the road surface,” measuring surface irregularities, puddles, ice patches, etc., pairing this info with high-accuracy GPS data, storing it to the cloud then sharing it with vehicle-to-vehicle applications, using it to plot the smoothest course between bumps, and “remembering” how deep to press the tires into each pothole.
ClearMotion aims to offer the ultimate digital ride experience from tire contact patch to seat in everything from passenger vehicles to commercial and agricultural equipment. The Bose ride will isolate ride inputs on vehicles with the stiffest springs. I very much look forward to channeling the spirit of Amar Bose and assessing this system against Audi’s electromechanical AI Active Suspension on the A8 and a Mercedes electrohydraulic system that’s coming on the next GLS- and S-Classes.