The Future of Brake Dynamometers


Dynamometers are at the very heart of the brake industry, but they are seldom the center of attention. Advances in dyno technology tend to happen on a case-by-case basis, with new functions added to machines for particular clients.

The BRAKE Report spoke with two dynamometer manufacturers about the industry’s most essential tool. The aim is to shine a spotlight on dynos and figure out where they are headed.

Terry Woychowski is the vice president of advanced technology development at Link Engineering. He’s quick to point out that innovation is spurred by customers.

“We work alongside our customers, which we’ve done for quite a while and continue to do. As they are continually exposed to new problems and new questions, they’ll come and talk to us, and we’ll scratch our heads together and work collaboratively with them to come up with new test devices, new equipment, new dynamometer capabilities to make sure they meet their engineering requirements.”

Chuck Greening of Greening Associates and Greening Testing Laboratories also stresses that innovation comes from customer requirements. “As a service provider and equipment manufacturer, we listen to our customers and try to understand their problems and bring the capability to address those problems into the lab — and therefore incorporate these features into the dynamometer.”

That doesn’t mean these companies aren’t thinking about what’s next. Woychowski’s job at LINK is to figure out what the company might be doing in the future. 

“As the great philosopher Wayne Gretzky said, ‘Don’t skate to where the puck is, skate to where it’s going to be.’ My job is to figure out where it’s going to be.” 

To do that job, Woychowski and his team study megatrends that are impacting the industry and society. From megatrends they drill down to impacts, and from there they create a technology roadmap “that helps indicate where we ought to be looking in terms of developing and evolving our test equipment.”

A Greening Testing Laboratories dyno

The Big Trends

Woychowski breaks down the big trends he sees into a few categories:

Emissions: “An emerging area of great interest is brake dust and brake emissions,” Woychowski says. He says LINK has been at the forefront of developing technology that can test for particulate emissions. One LINK dyno is in use for the California Air Resources Board, a state agency that could potentially be very influential in any future regulatory recommendations.

To zero in on emissions, a brake dyno requires extensive modifications. “We’re creating ductwork, electropolish ductwork, designs that follow isokinetic standards, and measurement equipment that can measure from 1 to 10 microns. We have to identify how many particles there are and how much they weigh.”

Regenerative inertia simulation: “With electrification, where some of the braking is regenerative and some is friction, to be able to simulate that is an area of growth,” Woychowski says. 

Including road load inputs: Woychowski cites this area as a prime example of making lab testing more closely replicate real-world conditions, modifying testing to include road loads, “if there are vertical or lateral forces being applied to this corner while you are braking, what are the effects of that.”

Better rotor crack investigations: Rotor cracks can be very small, begging the question of when a crack is a crack. Better equipment can quantify any cracks, giving the engineer much more design information.

Greening’s list of trends in dynos is similar. Chuck Greening emphasizes that dyno manufacturers face the question of how to conveniently incorporate what they know about vehicles into procedures that they can replicate in the lab — all part of making testing more closely resemble real-world conditions.

He adds another trend, which is more sophisticated application of existing technology. “There’s a lot of power in dynamometers even as they exist today that is really underutilized,” Greening says. “The procedures need to be enhanced to better reflect the use of the vehicle. We’re starting to see some of that. The ability to more easily gather vehicle data allows us to consider changing laboratory practices to reflect what’s really going on with the vehicle.”

From Knobs to Software

Greening and LINK are both family companies that have been in the testing industry for decades. Chuck Greening remembers working with the machines decades ago.

“I worked the floor. I have a lot of experience with operating the lab from a technician level. You used to have to turn knobs and dials in order to control the machine and make it go through different steps. Today that’s been taken over by software.”

“Turning the knob is like playing the organ. Today, controlling a dynamometer is akin to punching up some tunes on your phone.”

But, Greening says, that doesn’t mean dynos are easier to operate. Instead, they require a more technical skillset and a better understanding of what is being tested so that the operator can read the results as they come in and make sure the tests are proceeding correctly.

Woychowski points to a future in which mathematical models are increasingly important. He says, “One thing we know is that our OEM customers are on a perpetual quest to go from the road, to lab, to math.” He stresses that dynos will always have an important role to play and that LINK can assist clients as they move into increased reliance on mathematical modeling.

Prototypes are expensive and time-consuming. There’s pressure to replace testing on an actual vehicle with lab tests, Woychowski says. “For brakes, that means get on a dyno, to where it’s controllable, it’s repeatable, you don’t need the whole vehicle.”

“The pressure continues,” Woychowski says. “If you can do it in a laboratory, can you do it in a mathematical model on a computer. LINK will continue to play an important role in seamlessly integrating development and validation engineering efforts along the road-lab-math continuum.”


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The Brake Report

The BRAKE Report is an online media platform dedicated to the automotive and commercial vehicle brake segments. Our mission is to provide the global brake community with the latest news & headlines from around the industry.

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