*2.2.2. Test rig 02 (TR02) to verify the self-sensing behavior and force-sensorless controller*

In order to evaluate the ability of using the proposed self-sensing method and forcesensorless controller for any damping system using the same MR fluid damper, the second test rig (TR02) was set up as depicted in Fig. 4a. The system consists of the MR fluid damper investigated in the TR01 and a pneumatic actuator. The end-effector of this actuator is a pneumatic cylinder with 0.063m diameter which is driven by a 5/3-way proportional valve manufactured by Festo Corp. to generate the vibration for the damping system. The spool motion of this servo valve is proportional to its control signal sent from the PC through a D/A converter of the Advantech card 1711. A linear transducer (Novotechnik TR 100) was fixed on the TR02 base and this sensor slider was in contact with the cylinder end-position to feed back the vibration information to the PC. In addition, a loading system was installed in series with the damper rod to create the working environment. Here, the load can be manually varied while the compatible load cell with 5000N capacity made by Bongshin Corp. was chosen to measure and feedback the actual damping force in order to compare with the force predicted by the BBM and, consequently, to evaluate the self-sensing method. In addition, the proposed force-sensorless controller is applied to the TR02 to drive the MR fluid damper to follow desired force targets for controller verification.

For safety when doing experiments on the TR02, two limit bars were positioned at two sides of the loading system to restrict the piston movement, consequently, protecting the load cell and MR fluid damper from damages. A photograph of the TR02 configuration is described in Fig. 4b.

## **2.3. Experiments on the TR01and data analysis**
