Vandresen, M., Almeida, M., Sbardelotto, V., Cazangi, H. et al., "Automated Test System for Automotive Shock Absorber," SAE Technical Paper 2014-36-0227, 2014, doi:10.4271/2014-36-0227.
Automotive shock absorbers are key elements in the dynamic behavior of vehicles. Their degradation is slow, gradual and progressive, so that the driver of the vehicle eventually gets used to the decrease of the damper's performance without noticing it. This article describes how a test bench was developed based on existing market models, however having as its main goal the low cost of production. The Crankshaft and Scotch Yoke mechanisms were studied in an analog way and simulated in CAD software. After this analysis the Scotch Yoke system was chosen because its motion describes a perfect sine function. To drive the system it was used a 5HP electric motor, and a frequency inverter to control the motor's speed with capability of 7.33A, allowing the device to have the ability to test not only production line vehicles but also competition dumpers. The article describes the construction details of the bench built and also the embedded system chosen for the management of tests and recording and display of graphics using the Raspberry Pi in conjunction with displacement sensors, LVT (linear velocity transducer), accelerometer, infrared temperature, force load cell and position angle encoder. For human machine interface a screen was used along with a mouse and keyboard. The article presents preliminary tests, system settings and also different graphics that can be used to analyze the condition of automotive shock absorbers.