# Ground Simulation Tests in Two-Dimensional Dynamic Acceleration Environment
## 5 Verification Tests  
Figure 16 shows a photograph of the built simulation test system. Mechanically, the impact and flight 2-D dynamic AE was simulated using an air cannon propulsion, a motor relay, and a vector axial angle tracking. The system has been applied to the performance test of aerospace components. The load time and the amplitude of the 2-D acceleration were set according to the performance index of the unit being tested. The axial acceleration of the impact overload was set as 20 \(g\) and the radial acceleration was zero \(g\). The axial acceleration of the flight overload was maintained at 20 \(g\), while the radial acceleration was increased from zero \(g\) to 40 \(g\) within 0.5 s.  
Figure 14: Displacement curve produced by the cubic Hermite interpolation. Figure 15: Plots of the shaft angular displacement tracking based on the position–velocity–time (PVT) mode. The measured accelerations of the unit being tested with the synchronous loading are plotted in Figure 17. The simulation test process involved the following six steps. (1) The unit being tested was fixed on the vector turntable and the initial position of the unit being tested was vertical with the arm. The axial direction of the unit being tested pointed to the tangential direction of the arm, and the radial direction of the unit being tested pointed to the normal direction of the arm. (2) The electromagnetic clutch was disengaged, the asynchronous motor controlled based on ADRC accelerated to the set speed without the load, and the arm of the centrifuge remained stationary. (3) The air cannon received the launch order and the simulation of the launch AE of the unit being tested began at 1.5 s. The air cannon pushed the centrifuge arm, starting the movement of the arm instantaneously, and then the impact overload was achieved. The radial acceleration of the unit being tested coincided with the tangential acceleration of the arm. Meanwhile the electromagnetic clutch was engaged, and the vector turntable was controlled by the servo motor based on the PVT mode. The orderly transition between the impact overload and the steady-state overload was achieved. The axial direction of the unit being tested was along the direction of the resultant acceleration of the arm. When the clutch was fully engaged, the arm was driven by the motor. The axial acceleration reached 20 \(g\) within 120 ms and the radial acceleration briefly reached a maximum of 10 \(g\) during the axial acceleration. The radial acceleration dropped sharply. As could be seen, the maximum of the radial acceleration of the unit being tested was 30 \(g\) without the synchronous loading in Figure 11, while it was 10 \(g\) with the synchronous loading in Figure 17. The maximum of the radial acceleration was greatly reduced, and this amount was safe and acceptable. It was verified that the acceleration could be effectively regulated by synchronous loading of 2-D dynamic acceleration. (4) The unit being tested was rotated 90\({}^{\circ}\) and the axial direction of the unit being tested pointed to the pivot of the arm. The axial direction of the unit being tested pointed to the normal direction of the  
Figure 16: The built simulation test system. Figure 17: 2-D dynamic acceleration test results of the unit with the synchronous loading. arm, and the radial direction of the unit being tested pointed to the tangential direction of the arm. The system ran stably and maintained the launch state. The radial acceleration of the unit was reduced to zero \(g\), and the axial acceleration was unchanged. (5) The unit being tested received the flight order and the simulation of the flight AE began at 3 s. The centrifuge accelerated again, and the servo motor controlled the rotation angle of the unit being tested. By decomposing the resultant acceleration of the arm in two dimensions and maintaining the axial acceleration of the unit being tested constant, synchronous loading of 2-D dynamic acceleration was realized.