DEARBORN - Years before a vehicle ever appears on the road, Ford begins working on how to make it robust against potholes.
“We do a tremendous amount of upfront engineering to protect the customer against potholes, and we work closely with Product Development early on to help engineer our vehicles to pass our durability requirements,” said Susan Cline, Road Load supervisor, Cars.
At the beginning of the process – when there are no actual vehicles yet – the team works with computer simulation models for durability applications.
“Our Road Load activity works with our partners in Vehicle Dynamics to define their desired ride for the vehicle and determines if their tuning package will pose a problem with potholes. After we obtain information, we model the tires, the suspension and all the tunings, simulate the square edge pothole event on the computer and look for results that we anticipate will pass the test,” said Cline. “We look at vehicle responses like how much the suspension drops into the pothole and how the wheel accelerates out of the pothole.”
Cline said one of the biggest challenges is balancing ride with durability.
“There is often what we call an attribute conflict between getting the desired ride in the car for the product and being able to pass durability testing for potholes,” she said, noting that the challenge is particularly great with vehicles that are offered with big wheels.
“More and more customers are opting for vehicles with bigger wheel rims and low-profile tires. They have short sidewalls that provide customers with a desired look and feel, but they are also much more prone to pothole damage,” she said. “That’s why we are highly engaged early in the Product Development process to try and analytically define how the vehicle should be tuned to meet those requirements in a way that satisfies both ride and durability.”
After the computer simulation work is completed during the design phase, prototype vehicles are built and tested over engineered square-edged potholes at Ford’s Michigan Proving Grounds. These potholes have been shown to produce good results against pothole damage in the field if this test is passed.
“That’s when the Road Load team instruments the vehicle and records measurements going over our squared-edged pothole lane,” said Cline. “If we get results that we are not happy with, we will work with the Vehicle Dynamics team to adjust the suspension parameters to get the loads to where we need them to be to pass the test.”
At the end of a program when an actual vehicle is produced, it goes through a final verification phase which is to run the square-edged pothole lane for many cycles and ensure that there is no wheel or tire damage.
“At this point in the process, we execute the pothole test again as a final sign off to verify that the vehicle meets all of the requirements,” said Cline.
Cline said Ford devotes a tremendous amount of Product Development time to addressing pothole issues because it is important to the customer.
“Upper level management and product management take this requirement very seriously, and if we have problems, they work very hard with us to address them,” she said. “A big portion of my work – at least 25 percent – is concentrated on getting the vehicle to behave well over potholes and other tough road surfaces so that hopefully our customers are replacing their wheels and tires less often.”