# New Actuation Control for Hybrid Electromagnetic Valve Train
## 4 Test Setup and Procedure  
This section presents the selection of the EM valve components, the experimental equipment, and the testing process. According to the simulation data of the EM valve, when the EM valve does not pass any current, the attraction force of the armature to the  
Figure 8: Magnetic circuit diagram of improved EM valve: (**a**) when the armature is at UPM and zero current; (**b**) during upper release pulse; (**c**) when the armature is released from the UPM; (**d**) during catching pulse; (**e**) when the armature is at LPM and zero current; (**f**) during lower release pulse; (**g**) when the armature is released from the LPM; (**h**) when catching current is passed. Figure 7: Magnetic flux flow: (**a**) when no current is passed; (**b**) during upper release pulse; (**c**) during catching pulse; (**d**) when no current is passed; (**e**) during lower release pulse; (**f**) when catching current is passed. body is 198.5 N. When the release current is supplied to release the armature, this attraction force is dropped to 79.6 N. Therefore, it is known from these simulation data that the selection range of the spring is between 79.6 N and 198.5 N. The spring force cannot exceed this range; if it does, the armature will not work. Japanese standard flat wire die springs (KM08\(\times\)45) were used for this actuator [23]  
When the EM valve is operating, the total stroke of the armature displacement is 8 mm, which was designed to match the EM valve mechanism. The components of the EM valve are the body parts assembly, the permanent magnet placed on the winding of the coil, and the installed spring positioner. N35 high-temperature neodymium disc magnets were used for this actuator. These high-temperature magnets can work at temperatures of up to 300 \({}^{\circ}\)C, without losing their permanent magnetic properties [24]. In addition, the spring, and finally complete the EM valve body. There are two springs in total, which are installed above and below the spring positioner. It must be noted that the spring force of the single side is half of the sum of the springs. The range of a single spring constant after the calculation is between 0.5 kg/mm to 1.26 kg/mm. The EM valve in this study needs to be coiled with a wire, with current applied to the wire to generate a magnetic field to release and attract the armature. To improve the safety of the experimental test, 0.8 mm enameled wire (21 AWG) was selected as the coil. The highest withstandable current for this wire is 3.2 A. It is clear from the simulation data that the EM valve must be supplied with a current of 400 ampere-turns. Therefore, 200 turns of enameled wire were coiled on the EM valve, and then a current of was supplied to reach 400 ampere-turns. Two kinds of tests were conducted on the proposed EM valve and actuation. Figure 9a shows the maximum attraction force test platform. It is composed of a manual roller connecting screw to drive the platform. A 100 kg S-type load cell (FG5100) was used to measure the maximum attraction force of the EM valve. Start the test by keeping the armature at the UPM. Use the power supply to provide a fixed current, and the measurement range is 1\(\sim\)3 ampere, to measure sequentially. Start the measurement after the release current is provided. Reset the thrust count value to zero. When the release current is applied, rotate the screw of the test experiment platform to gradually apply thrust, to make the armature gradually leave the upper apex. When the armature is completely separated, stop rotating, and record the instantaneous maximum thrust, which is the release force of the EM valve. Figure 9b shows the EM valve operation test. A laser displacement sensor is used to measure the armature position with a high resolution of 2 \(\upmu\)m and the fastest sampling speed of 1 ms. This experiment uses a GPC-3060D power supply to provide current input. Figure 9: Test setup for (**a**) maximum attraction force and (**b**) EM valve operation.