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[Mikep99]

Looks like McLaren are leading the way in development

McLaren's 'J-damper' secret now exposed
http://en.f1-live.com/f1/en/headlines/news/detail/080821091858.shtml
So-called 'J-dampers' are set to become commonplace on Formula One cars, as the intriguing history of the previously secret technology is revealed.

We recently reported that Renault delayed debuting similar technology earlier this year because of the spy scandal surrounding engineer Phil Mackereth's defection from McLaren.

In the World Motor Sport Council hearings before Christmas, it was revealed that among Mackereth's McLaren drawings was a device referred to as a 'J-damper'.

"What's a J-damper?" Renault engineering chief Pat Symonds replied memorably to the press at Montreal in June.

Symonds' answer may have been disingenuous, but it subsequently emerged that Force India recently started using on its 2008 car what boss Mike Gascoyne referred to as an "inerter damper".

'J-damper' was simply a codename developed by McLaren and the technology's inventor to put their rivals off the scent of what the device actually did.

McLaren has been using the inerter damper since 2005 - a year before Renault's mass damper system was banned.

It has emerged that, three years ago, McLaren penned an exclusive confidentiality agreement with the famous Cambridge University, the scene of the J-damper's birth and the owner of its patent.

Business Weekly reports that, with the McLaren agreement now lapsed, Cambridge has licensed the J-damper to the leading damper company and F1 supplier Penske Racing Shocks, thus allowing any other team to deploy the device.

Penske Racing Shocks' technical director Jim Arentz said: "We are confident that the ingenuity of Cambridge now combined with Penske ... will promote greater exposure of the inerter in motor sport."

[McLaren Fan]

From F1 Live:

So-called 'J-dampers' are set to become commonplace on formula one cars, as the intriguing history of the previously secret technology is revealed.

We recently reported that Renault delayed debuting similar technology earlier this year because of the spy scandal surrounding engineer Phil Mackereth's defection from McLaren.

In the World Motor Sport Council hearings before Christmas, it was revealed that among Mackereth's McLaren drawings was a device referred to as a 'J-damper'.

"What's a J-damper?" Renault engineering chief Pat Symonds replied memorably to the press at Montreal in June.

Symonds' answer may have been disingenuous, but it subsequently emerged that Force India recently started using on its 2008 car what boss Mike Gascoyne referred to as an 'inerter damper'.

'J-damper' was simply a codename developed by McLaren and the technology's inventor to put their rivals off the scent of what the device actually did.

McLaren has been using the inerter damper since 2005 - a year before Renault's mass damper system was banned.

It has emerged that, three years ago, McLaren penned an exclusive confidentiality agreement with the famous Cambridge University, the scene of the J-damper's birth and the owner of its patent.

Business Weekly reports that, with the McLaren agreement now lapsed, Cambridge has licensed the J-damper to the leading damper company and F1 supplier Penske Racing Shocks, thus allowing any other team to deploy the device.

Penske Racing Shocks' Technical Director Jim Arentz said: "We are confident that the ingenuity of Cambridge now combined with Penske... will promote greater exposure of the inerter in motor sport."

Source: GMM
© CAPSIS International

[kitchen]

"What's a J-damper?"

He's not the only one asking that question.

[Mikep99]

Professor Malcolm Smith's inerter raced in Formula One
http://www.eng.cam.ac.uk/news/stories/2008/McLaren/
It has been reported recently in the motorsport press that Professor Malcolm Smith's "inerter" device and concept has been deployed in Formula One racing (e.g. Autosport, May 29, 2008, page 33, "Mark Hughes on... A genius idea, and why McLaren hasn't tried to stop others using it"). McLaren signed an agreement with the University for rights to exploit the technology in Formula One. After a rapid and confidential development process the inerter was raced for the first time by Kimi Raikkonen at the 2005 Spanish Grand Prix, who achieved a victory for McLaren. The inerter had been used for the first time in practice by McLaren at the previous race at Imola.

During development McLaren invented a decoy name for the inerter (the "J-damper") to keep the technology secret from its competitors for as long as possible. The inerter featured in the 2007 Formula One "spy scandal" when it was reported that the Renault engineering team failed to understand the purpose of the device from a McLaren J-damper drawing they had acquired - see the FIA World Motor Sport Council Decision, 7 December 2007. The fact that the J-damper is an inerter was revealed in the Autosport article. Cambridge Enterprise, the commercialisation office of the University of Cambridge, has now entered into a licence agreement with Penske Racing Shocks enabling Penske to supply inerters to any team in Formula One.

The inerter is a device which provides a force proportional to the relative acceleration between its attachment points ("terminals") which must be freely and independently movable in space. A typical realisation incorporates a flywheel which rotates in proportion to the relative displacement between the terminals. The first publication on the subject, in which the word "inerter" was coined, was: "Synthesis of Mechanical Networks: The Inerter" (M.C. Smith, IEEE Transactions on Automatic Control, Volume 47, Number 10, Pages 1648- 1662, October 2002). A patent on the device had previously been filed by the University.

The motivation for the inerter lies in the fields of electrical circuit synthesis and control systems. Classical circuit theory describes how to build circuits with the most general passive electrical impedances. Only three component types are needed: inductor, resistor and capacitor. There is an unexpected problem in translating this theory over to mechanical networks. Both the spring and damper have two terminals, but in contrast, the mass element has only one independently movable terminal. To achieve the greatest freedom to synthesize passive mechanical impedances a new element is needed which has two attachment points and where there is a proportionality between force and relative acceleration.

In a Formula One car the inerter can be used to improve "mechanical grip", i.e. to reduce tyre load fluctuations in dynamic situations. In conventional suspension design it is common to explain the role of individual components such as springs and dampers in achieving the overall goal. It is then natural to ask the question: what does the inerter do? Since the inerter is an energy storage element (like the spring) and not a dissipator (like the damper), an explanation in conventional terms is not immediately obvious. It is the fact that the inerter acts in combination with other elements (springs, dampers and masses) that the overall goal is achieved. To exploit the inerter the suspension designer is led to new methods which have their origin in electrical circuit synthesis.

It is pleasing that an idea which began with fundamental theoretical work in the Cambridge control group has led to this high profile exploitation in motor sport. Work is ongoing in the group to bring other applications of the inerter to fruition, e.g. in (1) vehicle suspensions for conventional road vehicles, (2) the control of motorcycle steering oscillations.

[McLaren Fan]

Again, another good read. Thanks.

[FerrariFan63]

This article is internally inconsistent. You can't have something that's both secret and patented, as the patent requires disclosure of the design.

[McLaren Fan]

McLaren had an agreement with Cambridge for the technology to remain secret. After this agreement expired, Cambridge were free to tell the world about it. The term J damper was then coined by McLaren and the part's designer to distract people from what it was meant to be for as long as possible. Some other teams found out about regardless of the decoy. Renault referred to their computer files from McLaren.

[f1alltimefan]

A new magazine article revealing the background and technical information on the 'J-damper' (inerter) is available at the following site:

http://ieeexplore.ieee.org/xpl/freeabs_ ... er=4799270

Enjoy!