What does fun have to do with engineering?
|A fully instrumented Ford Focus is used for objective testing by vehicle dynamics engineers. The Focus is a product of Ford's commitment to building cars with good driving dynamics.|
Consider this explanation from Ford group vice president for product development Richard Parry-Jones: "We're building into each of our vehicles a driving identity that customers around the world will recognize and associate with Ford cars and trucks. One metric we have is the 50-meter test. A vehicle must communicate to the driver in the first 50 meters a feeling of being fun to drive. We want to create an instantaneous recognition that `This car drives like a Ford.' That positive identity is being developed into the DNA of each of our vehicles so that customers throughout the world will consistently enjoy the pleasure of driving and the reassurance of control."
Therefore, "fun," while sounding like a marketing issue, is first and foremost an engineering one. So how does Ford design and build enjoyment into the driving experience on every Grand Marquis, Windstar or Protegé? That's the job of the vehicle dynamics engineers. They start by "thinking like a customer," a basic principle of Ford 2000, which leads to the first realization concerning fun. Customers don't really care about management's holy grail—faster-cheaper-better—because customers are only concerned with the end product. That makes reduced development time, lowered component price and improved build quality worthless goals if the car is a dud. Don't get me wrong. Ford still cares very deeply about faster-cheaper-better and they still have goals for these issues. However, Ford realizes that these goals need to be in harmony with the overall aim of producing a car with good "driving dynamics." So the vehicle dynamics engineers set targets for agility, comfort, precision, and stability for each vehicle model. These targets, if they're met, will presumably ensure the "dynamic identity" of that vehicle, i.e., it's going to be a fun car to drive.
So how do they determine these targets and how do they ensure that they're met, within the constraints of faster-cheaper-better? Ford uses three complementary and interdependent testing methods to guide a design concept: objective testing, subjective testing and computer-aided engineering (CAE).
|The Focus as a CAE model. While CAE is great for determining the viability of build combinations, optimizing design of experiments, and testing and fine-tuning designs, it's only one tool in the quest to engineer good driving dynamics.|
- Objective testing includes kinematics and compliance (K&C) testing in Ford's K&C Laboratory, as well as on-road and on-track testing of instrumented prototypes. This data is used to correlate the CAE models, as well as verify that the models' projected results actually happen in the real world. Better statistical information up front in the design process means an easier time later, with fewer problems when the manufacturing stage is reached.
- CAE models are used to give the vehicle dynamics engineers an unlimited testing palate to analyze the performance of components and systems before they become actual prototypes. Ford has seen CAE modeling grow from about 1,000 models per year in 1993 to approximately 100,000 models per year currently. During this time, every Ford vehicle program throughout the world, as well as those at Jaguar and Mazda, has moved to using the same software tool set. Suppliers are also using Ford-specific CAE tools through a special licensing agreement.
One effective way that vehicle dynamics engineers use CAE is to translate the complex equations of CAE-modeled vehicles into algebraic spreadsheets. These spreadsheets can then be used to create limits and predictions for design changes. Since they're portable, the spreadsheets are invaluable in design meetings where vehicle dynamics guys can bring them in on a laptop and determine the acceptability of changes and compute production tolerances on the spot. By working closely with the manufacturing people in this way, starting at the beginning of the development process, it helps to decrease development time and reduce prototyping. This makes management happy without sacrificing driving dynamics on the altar of cost-savings.
•Subjective testing includes driving prototypes and comparing them to benchmark vehicles under a variety of conditions to gather real driving impressions. Greg Stevens, Ford CAE supervisor, explains that "no computer can ever totally replace the feel, talent and intuition of an experienced development engineer." This is the human factor that ultimately ensures fun—no matter what a computer model says, no matter what empirical data is gathered, the vehicle still has to pass Parry-Jones' 50 meter test.