The Bose™ Suspension System

[Highway Ranger]

We always have discussions on ride quality and handling. In the current setup you have to either comprise on ride quality or handling.With Bose suspension, you can eat the cake and have it too.

Resolving the conflict between comfort & control

The Challenge

Every automotive suspension has two goals: passenger comfort & vehicle control. Comfort is provided by isolating the vehicle's passengers from road disturbances like bumps or potholes. Control is achieved by keeping the car body from rolling & pitching excessively, and maintaining good contact between the tyre and the road.

Unfortunately, these goals are in conflict. In a luxury sedan the suspension is usually designed with an emphasis on comfort, but the result is a vehicle that rolls & pitches while driving and during turning and braking. In sports cars, where the emphasis is on control, the suspension is designed to reduce roll & pitch, but comfort is sacrificed.

Bose engineers took a unique approach to solving this problem, and the result is an entirely new approach to suspension design.

The Solution

In 1980, Bose founder and CEO Dr. Amar Bose conducted a mathematical study to determine the optimum possible performance of an automotive suspension. The result of this 5-year study indicated that it was possible to achieve performance that was a large step above anything available. After evaluating conventional & variable spring/damper systems as well as hydraulic approaches, it was determined that none had the combination of speed, strength and efficiency that is necessary to provide the desired results. The study led to electromagnetics as the one approach that could realize the desired suspension characteristics.

The Bose suspension required significant advancements in four key disciplines: linear electromagnetic motors, power amplifiers, control algorithms and computation speed. Bose took on the challenge of the first three disciplines & bet on developments that industry would make on the fourth item.

The System

The Bose™ suspension system includes a linear electromagnetic motor and power amplifier at each wheel, and a set of control algorithms. This proprietary combination of suspension hardware & control software makes it possible, for the first time, to combine superior comfort & superior control in the same vehicle.

Linear Electromagnetic Motor

A linear electromagnetic motor is installed at each wheel of a Bose equipped vehicle. Inside the linear electromagnetic motor are magnets & coils of wire. When electrical power is applied to the coils, the motor retracts and extends, creating motion between the wheel & car body.

One of the key advantages of an electromagnetic approach is speed. The linear electromagnetic motor responds quickly enough to counter the effects of bumps & potholes, maintaining a comfortable ride. Additionally, the motor has been designed for maximum strength in a small package, allowing it to put out enough force to prevent the car from rolling & pitching during aggressive driving maneuvers.

Power Amplifier

The power amplifier delivers electrical power to the motor in response to signals from the control algorithms. The amplifiers are based on switching amplification technologies pioneered by Dr. Bose at MIT in the early 1960s — technologies that led to the founding of Bose Corporation in 1964.

The regenerative power amplifiers allow power to flow into the linear electromagnetic motor and also allow power to be returned from the motor. For example, when the Bose suspension encounters a pothole, power is used to extend the motor and isolate the vehicle's occupants from the disturbance. On the far side of the pothole, the motor operates as a generator & returns power back through the amplifier. In doing so, the Bose suspension requires less than a third of the power of a typical vehicle's air conditioner system.

Control Algorithms

The Bose suspension system is controlled by a set of mathematical algorithms developed over 24 years of research. These control algorithms operate by observing sensor measurements taken from around the car and sending commands to the power amplifiers installed in each corner of the vehicle. The goal of the control algorithms is to allow the car to glide smoothly over roads and to eliminate roll and pitch during driving.

Applied Learning

In many of today's production vehicles, the suspension system is comprised of front & rear suspension modules that bolt to the underside of the vehicle. The Bose suspension takes advantage of this configuration by creating replacement front & rear suspension modules. Thus Bose suspension was retrofitted into existing production vehicles with minimal modifications.

Bose's front suspension modules use a modified MacPherson strut layout and the rear suspension modules use a double-wishbone linkage to attach a linear electromagnetic motor between the vehicle body and each wheel. Torsion springs are used to support the weight of the vehicle. In addition, the Bose suspension includes a wheel damper at each wheel to keep the tyre from bouncing as it rolls down the road. Unlike conventional dampers, which transmit vibrations to the vehicle occupants and sacrifice comfort, the wheel damper in the Bose system operates without pushing against the car body, maintaining passenger comfort.

Vehicle Performance

Vehicles equipped with the Bose suspension have been tested on a variety of roads and under many different conditions, demonstrating the comfort and control benefits drivers will encounter during day-to-day driving. In addition, the vehicles have undergone handling and durability testing at independent proving grounds.

For the first time, the Bose suspension demonstrates the ability to combine in one automobile a much smoother ride than any luxury sedan and less roll and pitch than any sports car. This performance results from a proprietary combination of suspension hardware and control algorithms.

Some amazing video demos

Cornering

BOSE®

Slalom

BOSE®


Lane change

BOSE®

Parking lot bump

BOSE®

Speed Bump

BOSE®

Source Bose website

 

[Umang]

but bose is supplier to big automotive brands. we cant get it done after market. can we??

 

[Iron Rock]

but bose is supplier to big automotive brands. we cant get it done after market. can we??

Aftermarket is next to impossible especially with this bose patented system, infact this suspension has been proposed since several years now - its 20 years + its been under R&D and bose is extremely secretive about it, its based on electromagnetic principles and is highly effective. But the unfortunate problem is the very high cost and the ability to productionise this. This suspension created a lot of interest in the industry initially but hardly has anyone been able to have this in a production vehicle..Bose was considering a plan to introduce this with a luxury car manufacturer

This type of suspension is also popularly called Active suspension and many variations exist and some of the high end cars have it including the Ferrari 599 - please note this is not the bose one but kind of similar concept.

this is indeed cutting edge precision engineering and making it adapt and working in real world conditions - i hope some day it could be part of a production line.
Heard a friend who saw a demo once say - on a test obstacle track with speed breaker and uneven potholes u could place a coffee mug in the back seat and not a drop would spill. Dunno how true that is

But thanks for rekindling this topic - its a state of art thing!!

 

[Surfer]

but bose is supplier to big automotive brands.

Any example please.

 

[zengetz]

Here you go, Top notch suspension system from Bose. Watch it to believe it!
Bose suspension demo at Bose HQ - YouTube

 

[Highway Ranger]

He must have meant Bosch not Bose. Bose is very secretive about the whole project and have not let any reporter ride in their test cars.

It would be perfect for Indian roads and speed bumps

The website says it can be fixed in most cars with little alteration, but inputs to the suspension system, like the speed etc will have to be tapped from the car's sensors.

I wouldn't mind spending a lakh rs to have it fixed to my car.

 

[jayadev]

I think Rolce royce is the only car which uses this suspension .

 

[zengetz]

Here's one more video of the suspension system.
Bose suspension demo at Bose HQ - YouTube

 

[Iron Rock]

I think Rolce royce is the only car which uses this suspension .

I dont think any manufacturer has the bose suspension yet..has been in the works for so long, not sure wht they are up to or intending to do..there's more to this than what is available in public domain...

rolls has the citroen patent rather...and uses other active suspension components too

 

[carabiker]

Good to see thread about Bose suspension system here. I remember studying about it in late 90's and seeing same videos of cars on test track as shown above. I hope ,more car manufacturers adopt this system.

But imagine if all Indian vehicles are fitted with Bose Suspension, Authorities dont need to repair roads ever

 

[sandy_fluidic]

Similar kind of video was shown in our college by Merc during our annual technical festival in Pune. The test was done in germany. A full glass of water was kept at rear seat and the car was driven testing tracks. Not a single drop of water was fall. I dont remember the suspension system but now doubt that it will be same like Bose.

 

[cooldhaya]

Wow great videos guys , this is news to me! Thanks for sharing! Is this something similar to the air suspension we see in A8 and 7 series?

 

[Highway Ranger]

No, I think it is completely different. It is proactive and acts according the the road condition.

 

[Himanshu_Verma]

Another similar system developed by Delphi(Magneride) is already in use by various manufacturers like Lambo, Ferrari, Chevy, BMW, Audi etc