Developed and manufactured by Trend Performance Inc. (Warren, MI) in cooperation with automation company CIM Systems Inc. (Noblesville, IN), the system uses lasers and high-speed video cameras to measure valve train characteristics, such as valve bounce, lofting, spring harmonics and pushrod deflection. In addition to racing teams, OEMs also use the machine for testing high-performance engine parts.
According to CIM Systems' president, Dave Fox, when in use, Spintron employs an electric motor to spin the engine via a dummy crankshaft. This, in turn, spins the valve train, in an approach called "motoring." During actual testing, the Spintron will turn the engine at a number of predetermined speeds, recording and graphing data from a variety of sensors at each setting.
Early on in the development process, Fox says his team had problems finding a drive system capable of keeping up with his testing program.
"When we first developed [Spintron] in 1994, there weren't a lot of companies that made drives that communicated with the computer at a high rate of speed," Fox says. "Most were designed to follow an analog signal, requiring a programmable controller or some device outputting a 0- to 10-volt signal. Then, the drive would use that reference to adjust its speed. We definitely wanted the capability to talk directly to the drive through a communications port.
"Also, our previous drive would struggle if we attempted to make a ramp and RPM change in less than 1 second, so we started looking for a drive that would provide faster, and more accurate response."
Ultimately, Fox went with an ACS800 drive with direct torque control (DTC) from ABB Inc. (New Berlin, WI). The drive receives commands from the computer via Profibus or a direct fiber optic link, and adjusts the speed and torque of the motor to control speed and acceleration. The system's DTC feature monitors and adjusts the AC motor torque approximately 40,000 times per second. This ensures accuracy and enables the dynamics of the load to be applied to the test stand.
The result is that the ABB ACS800 accurately simulates real-time conditions, providing an accurate picture of precisely how an engine will perform at speed.
"[Using the ACS800] we can collect and graph data across a predefined range of RPMs, and then compare the results," Fox says. "With our old drive...the response time between RPM changes was sluggish and therefore did not provide an accurate representation of on-track RPM changes. With the ABB drive, we are able to send ramp and speed data to the drive 10 times faster for better test resolution and accuracy."
As an added benefit, CIM Systems installed a DDCS card from ABB, a fiber optic communication card that works with ABB's DriveWindow software package. The DDCS board sits inside the drive and allows the user to communicate with the drive from a laptop. With DriveWindow, a new drive parameter set can be easily saved to a PC. Because DriveWindow uses a high-speed fiber optic cable network for communication between the drive and PC, the system is fast, safe and immune to electrical noise.
For more on engine testing, call 586-447-0400, visit www.spintron.com or eInquiry 3.
For more on automated systems integration, call 317-773-5600, visit www.cimrobotics.com or eInquiry 4.
For more on drive control, call 800-752-0696, visit www.abb-drives.com or eInquiry 5.
