The thing about active suspension systems in cars is that they really aren’t.
The misconception behind “active” suspension systems is that they’re actually not active at all.
The reason? An active suspension needs to know the upcoming road profile to be able to adjust for it. Automotive manufacturers and suppliers continue to develop active actuating suspension systems, but the road profile data they use is not always measured in real-time. A professor and graduate student at Lawrence Technological University aim to change that, using LIDAR to sense the road ahead and have the suspension system respond in real time to keep a car on an even keel.
James Mynderse, associate professor in LTU’s A. Leon Linton Department of Mechanical, Robotics, and Industrial Engineering, said one of his graduate students, Dane Morison, “had an interest for his thesis in active suspension systems. Despite the development of preview-based control methods, there isn’t a lot of literature on the actual sensor that tells the vehicle what’s ahead so the active suspension system can respond to that.”
Morison hit upon using LIDAR as the sensor to provide a signal to the active suspension system to improve ride comfort. He’s conducting simulations of the sensor and the resulting suspension responses using MATLAB software in LTU’s Rockwell Automation Controls Industry 4.0 laboratory.
And by the way, that’s a completely new use for that laboratory, which was designed to model manufacturing processes and warehousing systems in modern, automated factories and warehouses. Morison is instead using its moving track to place obstacles like mock potholes and speed bumps in front of a model vehicle. A LIDAR sensor picks up the obstacles and has the vehicle’s suspension respond.
“We’re treating the assembly line simulator here as a scaled-down road surface,” Morison said. “It’s a lot of trigonometry.”
Morison hails from Sexsmith, Alberta, Canada, and earned his undergraduate degree from the University of Calgary. He came to Michigan after graduation to work in the auto industry. “After two years here I decided to get a master’s, and I looked at schools and their research capabilities, and LTU had automotive-focused research facilities, and that’s mostly why I chose it,” Morison said.
Morison said he and Mynderse discovered in preliminary research that active suspension systems use hard-coded responses to road conditions developed in simulations, “so there was no active, truly real-time road profile management system. That’s where I knew I could fill a void.”
Morison said his proof-of-concept system uses a marriage between a LIDAR and other sensors such as accelerometers and linear potentiometers to scan the “road” ahead, but that a fully developed system would use an array of LIDAR sensors for a more accurate map of upcoming road features.
And industry is already very interested in his research. Through LTU and its patent law partner, Ward Law, a provisional patent has already been granted for the system, and he and Mynderse are now in talks with a major global auto supplier toward a non-disclosure agreement for the details of the research and the system.
Morison’s preliminary research paper on the novel system, “A Simulation Model for an Online Corrective Look-Ahead Road Profiling System (CLARPS) for Active Suspension Applications,” was selected last year as one of the best papers from SAE WCX 24, the former SAE World Congress, and was selected for publication in SAE’s International Journal of Advances and Current Practices in Mobility. His latest research, which includes experimental results from the LTU labs, will be presented in April at SAE WCX 25.
By: Matt Roush
