SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO- RHEOLOGICAL DAMPERS PART Ⅱ—EVALUATION OF SUSPENSION PERFORMANCE

The design and analysis of an intelligent vehicle suspension with MR dampers should address hybrid semi-active control goals, such as rejection of current-switching discontinuity and MR-damper hysteresis, asymmetric damping from the symmetric MR-damper design, robustness on the vehicle operation parameter uncertainties and consideration of essential multiple suspension goals. Following the proposed skyhook-based asymmetric semi-active controller （Part I ） for achieving the above goals, herein, a set of suspension performance measures and three kinds of varying amplitude harmonic, rounded pulse and really measured random excitations are systematically defined, and the sensitivity of quarter-vehicle MR-suspension performance to variations in operating conditions is thoroughly analyzed. The results illustrate that the proposed skyhook-based semi-active MR-suspension in the asymmetric mode yields relatively superior dynamic responses to meet the multiple suspension performances of ride, rattle space, road-holding and dynamic tire force transmitted to the pavement, and has desirable robustness on variations in operating conditions of vehicle load and speed and the road roughness.     

SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO-RHEOLOGICAL DAMPERS:PART III——EXPERIMENTAL VALIDATION

A hardware-in-the-loop (HIL) test and simulation platform is developed in the laboratory, so as to validate the performance characteristics of the proposed skyhook-based asymmetric semi-active controller in Part I, and examine the validity of the proposed MR-damper model in a system surrounding. A real-time monitor is designed to assess and monitor the responses of the quarter-vehicle model in the HIL platform, and to select the excitation, controller synthesis, and the output displays. A drive current circuit hardware employing PID feedback technique is developed to compensate for the time delays from the servo-controller and drive current circuit, in which a small resistance is integrated in the current amplifier circuit to provide the feedback signal. The experiments were performed to measure the responses of the quarter-vehicle MR-suspension models with fixed current and the proposed semi-active MR-damping variations, under harmonic, rounded pulse and random road excitations. The measured data were compared with the corresponding model results to examine the model and controller validity, and revealed generally good agreements in the model and tested results and very little sensitivity of the tested responses to variations in the sprung mass. The HIL test results validate the effectiveness of the proposed skyhook-based semi-active asymmetric controller and its high robustness against the vehicle load variations in view of the intelligent vehicle suspension design.     

SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO- RHEOLOGICAL DAMPERS: PART Ⅰ-CONTROLLER SYNTHESIS AND EVALUATION

A modified skyhook-based semi-active controller is proposed for implementing an asymmetric control suspension design with symmetric magneto-rheological (MR) dampers. The controller is formulated in current form, which is modulated by integrating a continuous modulation and an asymmetric damping force generation algorithms, so as to effectively minimize switching and hysteretic effects from the MR-damper. The proposed controller is implemented with a quarter-vehicle MR-suspension model, and its relative response characteristics are thus evaluated in terms of defined performance measures under varying amplitude harmonic, rounded pulse and random excitations. The sensitivity of the semi-active suspension performance to variations in controller parameters is thoroughly evaluated. The results illustrate that the proposed skyhook-based asymmetric semi-active MR-suspension controller has superior robustness on the system parameter variations, and can achieve desirable multi-objective suspension performance.     

SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO- RHEOLOGICAL DAMPERS： PART Ⅲ-EXPERIMENTAL VALIDATION

A hardware-in-the-loop （HIL） test and simulation platform is developed in the laboratory, so as to validate the performance characteristics of the proposed skyhook-based asymmetric semi-active controller in Part I, and examine the validity of the proposed MR-damper model in a system surrounding. A real-time monitor is designed to assess and monitor the responses of the quarter-vehicle model in the HIL platform, and to select the excitation, controller synthesis, and the output displays. A drive current circuit hardware employing PID feedback technique is developed to compensate for the time delays from the servo-controller and drive current circuit, in which a small resistance is integrated in the current amplifier circuit to provide the feedback signal. The experiments were performed to measure the responses of the quarter-vehicle MR-suspension models with fixed current and the proposed semi-active MR-damping variations, under harmonic, rounded pulse and random road excitations. The measured data were compared with the corresponding model results to examine the model and controller validity, and revealed generally good agreements in the model and tested results and very little sensitivity of the tested responses to variations in the sprung mass. The HIL test results validate the effectiveness of the proposed skyhook-based semi-active asymmetric controller and its high robustness against the vehicle load variations in view of the intelligent vehicle suspension design.     

SEMI-ACTIVE CONTROL OF VEHICLE SUSPENSION WITH MAGNETO- RHEOLOGICAL DAMPERS： PART Ⅰ ——CONTROLLER SYNTHESIS AND EVALUATION

A modified skyhook-based semi-active controller is proposed for implementing an asymmetric control suspension design with symmetric magneto-rheological （MR） dampers. The controller is formulated in current form, which is modulated by integrating a continuous modulation and an asymmetric damping force generation algorithms, so as to effectively minimize switching and hysteretic effects from the MR-damper. The proposed controller is implemented with a quarter-vehicle MR-suspension model, and its relative response characteristics are thus evaluated in terms of defined performance measures under varying amplitude harmonic, rounded pulse and random excitations. The sensitivity of the semi-active suspension performance to variations in controller parameters is thoroughly evaluated. The results illustrate that the proposed skyhook-based asymmetric semi-active MR-suspension controller has superior robustness on the system parameter variations, and can achieve desirable multi-objective suspension performance.     

MODELING AND CONTROL OF A UNIVERSAL PART FEEDER

0 INTRODUCTIONPart feeding has historically been a prominent problem inmanufacturing. Up to 50% of the total manufacturing cost is as-sembly[1], and up to 30% of assembly cost is part feeding[2]. Parthandling and feeding have become even more difficult an…     

RESEARCH ON THE PERFORMANCE OF NEW TYPE OF PROPORTIONAL PESSURE AND FLOW CONTROL VALVE

A new closed loop flow controlling principle through correcting the valve's opening area while load pressure is changing is carried out. Further more a principle using only one proportional valve to compound control pressure and flow is suggested. By using very simple proportional throttle valve in structure, the functions that five kinds of proportional valves or any two of them combined possess can be complimented. After analyzing, comparing, and testing the dynamic and static characteristics of valve with different controlling principles and main valve structure styles, the optimized structure styles and control methods are achieved.     

IMPROVE THE KINETIC PERFORMANCE OF THE PUMP CONTROLLED CLAMPING UNIT IN PLASTIC INJECTION MOLDING MACHINE WITH ADAPTIVE CONTROL STRATEGY

The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment. The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.     

RESEARCH OF KINEMATIC CHARAC－TERISTICS FOR QUADRUPED WALKING VEHICLE WITH LEGS OF DIFFERENT DISPOSITIONS OF DOFS

ＲＥＳＥＡＲＣＨＯＦＫＩＮＥＭＡＴＩＣＣＨＡＲＡＣ－ＴＥＲＩＳＴＩＣＳＦＯＲＱＵＡＤＲＵＰＥＤＷＡＬＫＩＮＧＶＥＨＩＣＬＥＷＩＴＨＬＥＧＳＯＦＤＩＦＦＥＲＥＮＴＤＩＳＰＯＳＩＴＩＯＮＳＯＦＤＯＦＳＲＥＳＥＡＲＣＨＯＦＫＩＮＥＭＡＴＩＣＣＨＡＲＡＣ－Ｔ...     

EFFECT OF INVOLUTE CONTACT RATIO ON THE DYNAMIC PERFORMANCE OF SPUR GEAR WITH NOTOOTH PROFILE MODIFICATION

The effect of involute contact ratio on the torsional vibration behavior of spur gear-pair isstudied analytically through a mass-spring model. The tooth stiffness in model not only has a relationwith time, as many prior studies presented, but, more important, with involute contact ratio (ICR) aswell. The ICR embodies its impact on the spur gear's dynamic performance through changing theproportion of tooth stiffness when there are n+1 teeth in contact to tooth stiffness when there are n     

PRESSURE FORCE CONTROL FOR FABRICATION OF PLASTIC MICROFLUIDIC CHIPS WITH HOT EMBOSSING METHOD

A pressure force control system for hot embossing of microfluidic chips is designed with a moment motor and a ball bearing lead screw. Based on the numeric PID technique, the algorithm of pulsant integral accelerated PID control is presented and the negative effects of nonlinearity from friction, clearance and saturation are eliminated. In order to improve the quick-response characteristic, independent thread technique is adopted. The method of pressure force control based on pulsant integral accelerated PID control and independent thread technique is applied with satisfactory control performance.     

DESIGNING OF TWO NEW FUZZY CONTROLLERS WITH ERROR INTEGRAL AND THEIR APPLICATIONS IN FOLLOWING CONTROL OF WARSHIP-GUNS

Two new fuzzy controllers are designed, one's control rules are adjusted by error integral, another are with feedforward of error integral. If only the control rules and parameters are selected felicitously, the static errors of the system will be eliminated. The test results show that the controllers can assuredly improve static performances of the controlled system.     

INVESTIGATION ON NEW TYPE OF DOUBLY BLENDING ABRASIVE WATER JET NOZZLE SYSTEM WITH HIGHER PERFORMANCE

Based on the two existing abrasive water-jet(AWJ) systems, the dia-jet (or pre-jet) and the post-jet, a new type of abrasive water-jet system is put forward, which combines the dia-jet's advantage, low operating system pressure, slender stream jet, and more concentrative abrasive in the blended stream, with merits of post-jet, the less sophisticate apparatus, successive supply of abrasives. The theoretic analysis is brought out in detail, and the nozzle system structure is concisely illustrated. Its relevant experiment results are demonstrated, proving that this new system is effective in various aspects, enlarging penetrating capability without raising system pressure, saving machining power supply, lessening energy loss, etc.     

PREDICTION OF ACOUSTIC PERFORMANCE IN EXPANSION CHAMBER MUFFLERS WITH MEAN FLOW BY FINITE ELEMENT METHOD

The equation of wave propagation in a circular chamber with mean flow is obtained. Computational solution based on finite element method is employed to determine the transmission loss of expansive chamber. The effect of the mean flow and geometry (length of expansion chamber and expansion ratio)on acoustic attenuation performance is discussed, the predicted values of transmission loss of expansion chamber without and with mean flow are compared with those reported in the literature and they agree well. The accuracy of the prediction of transmission loss implies that finite element approximations are applicable to a lot of practical applications.     

ON THE DYNAMIC MODELING AND CONTROL OF 2-DOF PLANAR PARALLEL MECHANISM WITH FLEXIBLE LINKS

The object of study is about dynamic modeling and control for a 2 degree-of-freedom (DOF) planar parallel mechanism (PM) with flexible links. The kinematic and dynamic equations are established according to the characteristics of mixed rigid and flexible structure. By using the singular perturbation approach (SPA), the model of the mechanism can be separated into slow and fast subsystems. Based on the feedback linearization theory and input shaping technique, the large scale rigid motion controller and the flexible link vibration controller can be designed separately to achieve fast and accurate positioning of the PM.     

CONTROL STRATEGY OF A PARALLEL HYBRID CAR WITH A METAL BELT-PLANETARY GEAR CONTINUOUSLY VARIABLE TRANSMISSION SYSTEM

The most remarkable characteristic of a metal belt-planetary gear continuously variable transmission is a wider ratio range and a bigger torque capacity than a conventional metal pushing belt continuously variable transmission. A parallel hybrid car with this transmission system not only can reduce fuel consumption and pollutant emission at a ECE city cycle, but also can keep the motor working in the most efficiency area and can be started by a lower power motor by oneself. At the same time, the continuously variable transmission system can realize the smooth switch between the motor and the engine.     

THE UNIFIED-GENERALIZED MECHANICS OF CUTTING APPROACH—A STEP TOWARDS A HOUSE OF PREDICTIVE PERFORMANCE MODELS FOR MACHINING OPERATIONS

Abstract

This paper presents the series of on-going investigations, which led to the development of the ‘Unified-Generalized Mechanics of Cutting Approach’ to predictive modelling of various technological performance measures for the wide spectrum of machining operations used in practice. It is shown that this approach involved the development of generalized mechanics of cutting analyses of the cutting processes for machining with single edge and multi-edge (form) tools and the establishment of a generic database of basic cutting quantities and edge force coefficients. This was followed by the development of a methodology for modelling each machining operation used in practice, based on the generalized cutting analyses and database. The models developed for turning, drilling and milling operations as well as machining with form tools and the novel rotary tool turning operations are briefly described together with recent research on predictive modelling of ball end-milling and machine tapping operations. It is shown that the models for the different machining operations could be ‘unified’ into a modular computer application structure, drawing on the generic cutting analyses and database. This ‘unified’ approach could represent a step towards the development of a ‘House of Predictive Models’ sought by the CIRP Working Group on modelling of machining operations. The considerable scope for further research is discussed in this paper.     

STUDY ON CONTROL STRATEGY OF CLUTCH STARTING FOR CAR WITH A METAL PUSHING BELT-PLANETARY GEAR CONTINUOUSLY VARIABLE TRANSMISSION SYSTEM

0 INTRODUCTIONA metal pushing belt-p1anetary gear continuouslyvariable transbossion was invented by Macey andVahabzadeh in l987[1]. The most retnarkablecharacteristic of this tusAnssion is a wider rahorange than a conventional metal pushing beltcontinuously variable transndssion, and without areversal planeop gear, the transmission ratio range isconhnuously expanded from positive ratio to negahveratio through a zero ratio. So a metal pushing belt-planetary gear continuously variable tran…     

ADDITIONAL DESIGN FEATURES OF A MASTER–SLAVE CONTROL SYSTEM WITH FORCE SENSING AND ENERGY RECYCLING FOR UPPER LIMB REHABILITATION ROBOTS

Traditional upper-limb rehabilitation robots usually realize force feedback with force sensors or impedance controllers. Otherwise, assistant or resistant force required in different training modes is given by the robot, which does not motivate the initiative of patients sufficiently. This article introduces a self-controlled upper-limb rehabilitation robot to implement force sensing without a force sensor or an impedance controller. The system supports bimanual exercises in different training modes with one limb providing a proper force for the contralateral limb. The above characteristics and the capability of master–slave motion tracking with a kind of energy recycling were verified with preliminary experiments.