This paper presents torque control characteristics of ER (electro-rheological) and MR (magneto-rheological) clutches. As a first step, Bingham properties of ER and MR fluids are experimentally distilled under the shear mode. A nondimensional model of the clutches is established for reasonable comparison. Two clutches have the same principal design parameters such as outer radius of the disc and electrode gap size. Following the manufacturing of two clutches on the basis of the nondimensional model, field-dependent torque levels are experimentally evaluated. A PID (proportional-integral-derivative) controller is then designed and experimentally realized to achieve desired torque. Both regulating and tracking torque control responses of the two clutches are evaluated and compared. In addition, control durability for torque tracking is undertaken to provide a practical feasibility of the proposed clutches.

No abstract

No abstract

No abstract

No abstract

No abstract

This paper proposes a new type of an ER (electro-rheological) engine mount which has a mixed mode as fluid working mode (the combination of shear and flow modes). As a first step, a mixed mode ER engine mount, which is applicable to a medium-sized passenger vehicle, is designed and manufactured by incorporating Bingham model of the ER fluid. The vibration isolation performance of the ER engine mount with different intensity of electric fields is evaluated in the frequency domain and compared with that of conventional hydraulic type engine mount. Subsequently, a full car system installed with the proposed ER engine mounts is constructed and modeled by considering engine excitation forces. After deriving its governing equations of motion, HIh control algorithm is formulated by taking into account the semi-active actuating condition. The vertical engine displacement and body acceleration are evaluated via hardware-in-the-loop simulation (HILS) at various engine excitation frequencies.

This paper addresses an active vibration control of intelligent composite laminate structures containing an electro-rheological (ER) fluid. Firstly, complex shear modulus of the ER fluid itself is obtained as a function of imposed electric fields and excitation frequencies through a rotary oscillation test. By incorporating the measured complex modulus with a conventional sand wich beam theory, elastodynamic properties of the structures are then predicted. Subsequently, an experimental investigation is undertaken in order to identify modal characteristics such as damped natural frequencies, damping ratios, and mode shapes of the structures. As for the validation of the modeling methodology, the comparison between the predicted elastodynamic properties and the measured ones is performed. Characteristics of the ER fluid actuator explicitly representing the relationship between elastodynamic properties and imposed electric fields are also inferred. A control system model is then formulated by combining the actuator characteristics into a phenomenological governing equation of a finite element form. Based on the field-dependent frequency responses of the structures, an active control algorithm for accomplishing desired responses of the tip deflection is established. In addition, in order to validate the proposed control strategy, the measured desired responses by means of an experimental implementation are compared with the predicted ones through the proposed model in the frequency domain. Finally, the effectiveness of the proposed control model for avoiding resonance to variable disturbances is evaluated by presenting the controlled tip deflection of the employed composite structures with respect to control gain in the time domain.