A control chart to evaluate the control effect of a bridge under active control

To reinforce and improve the function of disaster relief light bridge, the developed Neutral Equilibrium Mechanism (NEM) was applied for controlling the internal force and reducing the vertical deformation of a bridge to form as virtual piers. The control force of NEM was generated by the Proportional–Integral–Derivative controller with a combination of the displacement GP, speed GD and adjusted GI gain coefficients to neutralize the vertical deformation of a bridge created by a moving live load and the dead weight of a bridge. To effectively evaluate the control efficiency of bridge deformation under this mechanism, a multi-dimensional quality evaluation method is proposed to assess the control benefits of bridge deformation under different combinations of control coefficients. The test and analysis results in control performance analysis chart show that it can be clearly observed the control performance index MTIi is around 2-3, 3 and 5 for the combination of GP = 0.5, GD = 0.0, GI = 0.02, GP = 1.0, GD = 0.0, GI = 0.02, and GP = 2.0, GD = 0.0, GI = 0.02 respectively. The analysis results present a clear demonstration of control performance, which can serve as a reference for future practical control safety.