Electromechanical Suspension Research Articles

Research on the configuration of electromechanical suspension based on inertial force attenuation structure

To address the critical challenges impeding the progress and utilization of electromechanical suspensions, this paper examines the negative consequences of inertial mass on the acceleration of the sprung mass and structural reliability issues. It then introduces and optimizes two novel suspension configurations featuring a series buffering and damping structure (SBDS). Subsequently, a two-degree-of-freedom electromechanical suspension model with SBDS is proposed and formulated. Utilizing the probability method, the paper also derives the vibration transmission characteristic formulas for the SBDS-integrated suspension. Theoretical analysis suggests that the integration of SBDS is advantageous in reducing the inertial force generated by the inertial mass in electromechanical suspensions. Additionally, the impact of parameter variations in SBDS on suspension characteristics is examined, providing theoretical guidance for the design of this structure. Building upon the proposed suspension theory incorporating the novel SBDS configuration, a butterfly spring buffer is employed to replace the connecting rod in the traditional electromechanical suspension design. Bench tests validate that the new electromechanical suspension configuration with SBDS addresses the issue of performance degradation in the high-frequency range due to inertial mass, thereby enhancing the overall performance of electromechanical suspensions and facilitating their further development and application.

Adaptive opto-electromechanical silicon-on-insulator increased bandwidth accelerometer

This paper studies the construction of a compact one-dimension-sensing iscreased bandwidth photonic accelerometer using cascaded groups of continued sections of a 50 ng seismic mass each attached to the silicon beams of two under etched slot waveguide electrostatic phase shift elements acting as voltage-controlled adaptive-precision springs. The accelerometer sensitivity is shown to be significantly increased by applying equal electrode voltages. Simulation results indicate that the sensitivity dynamic range is about 76 dB combining both open-loop and closed-loop voltage control of the sensor. The operation bandwidth of the accelerometer may be increased up to 250 kHz due to the cascaded multi-section architecture of the sensor. This advantage gives significant relief to the limitation in bandwidth response of single section counterparts. The sensor may be designed to detect impact accelerations up to 104 ms−2 and yet can still be electrostatically driven to detect sub-gravitational accelerations. The application of negative feedback voltage control to hold the seismic mass at close distances from a standstill is shown to significantly increase the acceleration detection range. The construction uses all in-plane components based on a silicon-on-insulator template with 300 nm of silicon core thickness. The proposed electromechanical suspension system and the electric feeding arrangements are the most simple. The accelerometer performance is theoretically deterministic. The study is based on performing numerical analysis for the electromechanical suspension system. The waveguides are simulated utilizing the VPIphotonics industry standard. Applications may include the automobile and aerospace industries, underwater sonar, industrial ultrasonic detection, seismology predictions, and medical ultrasonography.Article HighlightsThe cascading of compact high-speed accelerometer sections allows increasing the bandwidth response of the proposed sensor by many folds compared to its single-mass single-section counterparts.The suspension structure is electrostatically controlled by two voltages enabling widely controlling the sensitivity and detection range of the accelerometer.The proposed accelerometer may fit wide applications achieving high detection speeds and super sensitivities utilizing a small footprint and power-efficient structure.

Design on ADES Based on IFTDEPMG and its Efficiency Test

The accelerator/decelerator is the key part of the electromagnetic suspension (EMS) for it bears the function of torque changer and of speed changer synchronously. This paper introduces the scheme and working principle of electromechanical suspension for armored vehicles firstly. Then, the requirements of the accelerator/decelerator of the electromechanical suspension (ADES) are introduced according to the characteristics of armored vehicles. The accelerator/decelerator of an involute few-tooth-difference external parallel moving gear is designed, and an accelerator/decelerator prototype is tested on the bench. The results show that the accelerator/decelerator of the involute few-tooth-difference external parallel moving gear (IFTDEPMG) has high efficiency in bidirectional transmission, which satisfies the transmission requirements of electromechanical suspension in both active and passive conditions.

Mode control of electro-mechanical suspension systems for vehicle height, levelling and ride comfort

This paper proposes a mode control algorithm of electro-mechanical suspension for vehicle height, attitude control and improvement of ride quality. The proposed control algorithm consists of mode selector, upper-level and lower-level controllers, and suspension state estimator. The mode selector determines the present driving mode using vehicle signals, such as longitudinal speed, steering wheel angle, accelerator pedal position, brake pedal position and vertical acceleration of wheels. The upper-level controller determines the desired suspension state using the present driving mode. The lower-level controller derives the desired stroke speed of the actuator in each suspension by linear quadratic control theory. The suspension state estimator has been designed using accessible sensor measurement by discrete-time Kalman filter theory. The control and estimation algorithms have been developed based on a novel reduced-order vehicle model that includes only the vehicle body dynamics. The model enables the observer to completely remove the effect of unknown road disturbance on the estimation error. The performance of the proposed control algorithm has been evaluated via computer simulation study. The simulation results show that the proposed control algorithm is effective at controlling the electro-mechanical suspension systems. The paper also shows that the considered actuator is suited for vehicle height and levelling control, but not for improvement of ride comfort, due to voltage input constraints.

Performance of Electrically Small Conventional and Mechanical Antennas

Antennas that operate in the very low frequency (LF) band and below are useful for a number of applications, including long-distance and underwater communication. When constrained in size, the antennas are electrically small and very inefficient. This has motivated the need for novel approaches to LF antenna design. Here, we present concepts for antennas that generate electromagnetic signals from mechanical motion. We first review the generated fields and efficiency of conventional magnetic and electric dipole transmitters. This is then extended to their mechanical counterparts for comparison. Our results show that the motion of magnets or electrets (the electrical analog of a magnet) can efficiently radiate electromagnetic energy when coupled to a low-loss electromechanical suspension. Mechanical antennas, with spatial dimensions on the order of a meter, can theoretically exceed the performance of conventional short dipole and coil transmitters by more than eight orders of magnitude for frequencies of 1 kHz and below. This paper is intended to lay the foundation for future development involving the implementation of efficient, small form-factor, mechanically actuated antennas.

Electro-mechanical suspension system considering energy consumption and vehicle manoeuvre

In this paper, the performance of the electro-mechanical suspension is discussed on the energy consumption, vibration isolation, and vehicle manoeuvrability. On the basis of the formulation of electro-mechanical suspension, the energy consumption and vibration isolation are discussed through the contour maps with the sprung and unsprung mass velocity feedback gain axes. From the numerical simulation and experimental results, the contour maps for the evaluation of the performance with feedback gain axes are proposed, and on these maps, the abilities of vibration isolation and manoeuvrability are evaluated. On the energy consumption, the regeneration region exists, and the velocity feedback gain of unsprung mass should be considered for regeneration and energy saving. Moreover, Gain settings for improving each vehicle performance are proposed and verified by shaker tests. From simulation and experimental results, it is demonstrated that the proposed active suspension system is able to solve the compatibility between vibration isolation and energy saving.