776 research outputs found

    Modelling and Validation of an Electronic Wedge Brake System with Realistic Quarter Car Model for Anti-Lock Braking System Design

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    With the advancement in battery and electronics technologies, soon Electric Vehicles (EV) will replace traditional vehicles as they are more efficient and environment friendly. This will require replacement of all mechanical systems in vehicles with their electrical counterparts. This study focuses on electromechanical brakes (EMB) as replacement of hydraulics brakes. Particularly a type of EMB known as Electronic Wedge Brake (EWB) which uses wedges to create self reinforcing braking force and consume less power than other EMBs. Detailed mathematical model of an EWB system is presented which provides braking force and torque to the disk brake. A Quarter Car Model (QCM) with realistic parameter values and aerodynamic deceleration is modelled to validate the EWB system. The system is validated for different road conditions and anti-lock braking system (ABS) is demonstrated for snowy road using a single PID controller. The results validate the brake and car model and a need for cascaded control strategy to implement ABS is established

    Integrated braking control for electric vehicles with in-wheel propulsion and fully decoupled brake-by-wire system

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    This paper introduces a case study on the potential of new mechatronic chassis systems for battery electric vehicles, in this case a brake-by-wire (BBW) system and in-wheel propulsion on the rear axle combined with an integrated chassis control providing common safety features like anti-lock braking system (ABS), and enhanced functionalities, like torque blending. The presented controller was intended to also show the potential of continuous control strategies with regard to active safety, vehicle stability and driving comfort. Therefore, an integral sliding mode (ISM) and proportional integral (PI) control were used for wheel slip control (WSC) and benchmarked against each other and against classical used rule-based approach. The controller was realized in MatLab/Simulink and tested under real-time conditions in IPG CarMaker simulation environment for experimentally validated models of the target vehicle and its systems. The controller also contains robust observers for estimation of non-measurable vehicle states and parameters e.g., vehicle mass or road grade, which can have a significant influence on control performance and vehicle safety

    Perancangan Electromechanical Brake Untuk Kendaraan Perkotaan

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    Sistem pengereman memiliki fungsi menghentikan laju kendaraan. Sistem pengereman yang digunakan pada banyak kendaraan adalah sistem pengereman hidrolik. Namun sistem pengereman ini memiliki kelemahan yaitu respon lambat, lebih berat secara keseluruhan dan kebocoran fluida rem berbahaya. Untuk mengatasi kelemahan diatas, dirancang electromechanical brake system. Metode dalam tugas akhir ini adalah mengumpulkan data city car kemudian dirancang electromechanical brake berdasarkan clamping force. Ruangan yang tersedia panjang 350 mm, lebar 190 mm, dan tinggi 170 mm. Simulasi ini menggunakan solidworks untuk mengetahui apakah komponen dalam electromechanical brake ini mampu menahan clamping force. Dari perhitungan yang telah dilakukan sebagai berikut panjang 307 mm, lebar 166 mm dan tinggi 166 mm. Sebagai penggerak digunakan Planetary Gear, Motor tipe brushless DC Motor, Power Screw, Batang Poros, Batang Ayun dan sistem sambungan mekanisme yang terdiri dari Nut, Baut, Pin, Piringan Rem, dan Kampas Rem. Material yang digunakan adalah AISI 4340 Steel, Normalized yang memiliki nilai tegangan ijin maksimum 710.000.000 N/m2. Hasil simulasi dibagi dalam 3 bagian yaitu simulasi planetary gear dengan nilai tegangan maksimum sebesar 246.595.552 N/m2, simulasi terhadap Screw, nut dan head dengan nilai tegangan maksimum sebesar v 223.013.760 N/m2 dan simulasi terhadap batang poros dan batang ayun dengan nilai tegangan maksimum masing-masing sebesar 282.190.240 N/m2. Nilai tegangan maksimumnya lebih rendah tegangan ijin materialnya, sehingga perencanaan komponenkomponen ini aman ================================================================================================ The braking system has a function stop the vehicle. Braking systems are used on many vehicles is the hydraulic braking system. However, this braking system has the disadvantage of slow response, heavier overall and dangerous brake fluid leaks. To overcome the disadvantages of the above, designed electromechanical brake system. The method in this thesis is to collect data and then a city car designed by electromechanical brake clamping force. This simulation uses SolidWorks to determine whether the components in the electromechanical brake is able to withstand the clamping force. From the calculations have been carried out as follows length 307 mm, width 166 mm and height of 166 mm. As a driver used Planetary Gear, Motor type brushless DC Motor, Power Screw, Rod Shaft, Rod Ayun and connection system mechanism consisting of Nut, Bolt, Pin, disc brakes, and the brake lining. The material used is AISI 4340 Steel, which has a Normalized maximum allowable stress value 710 000 000 N / m2. The simulation results are divided into 3 parts, namely simulated planetary gear with a maximum stress value of 246 595 552 N / m2, a simulation of the Screw, nut and head with a maximum stress value of 223 013 760 N / m2 and a simulation of the shaft and rod swing with value The maximum stress respectively 282 190 240 N / m2. Lower maximum stress value vii allowable stress of material, so that the planning of these components saf

    The empact CVT : dynamics and control of an electromechanically actuated CVT

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    The large ratio coverage of a CVT and the possibility to choose the engine speed in a wide range independently of the vehicle speed enables the ICE to operate at more fuel economic operating points, making the vehicle potentially more fuel efficient. Unfortunately, because the energy dissipation of the CVT itself is higher than that of a manual transmission, this efficiency improvement is partly lost. The main power losses in the CVT are due to the inefficient hydraulic actuation system and the excessive clamping forces used to prevent the belt from excessive slippage. Direct control of the slip can significantly increase the efficiency. Due to the low actuation stiffness at low hydraulic pressures, the hydraulically actuated CVT is not well suited for slip control. The Empact CVT, developed at the TU/e, is an electromechanically actuated pushbelt type CVT, which has a high stiffness at low clamping forces and is suitable for slip control. This system reduces the steady-state losses, which are dominantly present in a hydraulic system. The goals of this research are to achieve optimal efficiency of this system, to obtain good tracking performance and to prevent the pushbelt from slipping excessively. These objectives are experimentally validated at a Empact prototype, which is tested at a test rig and implemented in an Audi A3 2.0 FSI. The Empact CVT uses two servomotors to actuate the moveable pulley sheaves. To decouple the rotation of the input and output shaft from the servomotor rotations, a double epicyclic set is used at each shaft. The system is designed, such that one (primary) actuator accounts for the ratio changes and one (secondary) actuator sets the clamping forces in the variator. To optimally use the efficiency potential of the Empact system, the slip in the variator must be controlled. In this way, the clamping forces reduce to small values, thereby reducing the friction forces in the gears, spindles and bearings. Efficiency improvements of up to 20 [%] can then be reached at partial load (during 75 [%] of the duration of the FTP72 cycle) compared to a conventionally controlled CK2 147 transmission and efficiency gains of up to 10 [%] compared to an optimally, slip controlled CK2. To gain insight in the physical behavior of the Empact CVT, a multi-body model of the system has been developed, which incorporates a dynamical description of all major components of the test setup. Results show a realistic behavior of the system for both stationary and transient situations. Although this nonlinear simulation model gives a basis for control design and yields a realistic description of the closed loop system, for the actual control design an approximate, linear plant model that describes the frequency domain behavior of the system is estimated. These linearized descriptions are obtained from the simulation model using approximate realization from pulse response data. An iterative model identification and control design procedure is used, such that the plant is estimated in closed loop. In this way, the uncertainty in the frequency range of importance for the design of the controllers is reduced, which leads to less conservative control designs. Parallel to the identification and control design with the simulation model, this procedure is also applied for the test setup. Due to high measurement noise and excessive friction in the system, the quality of the approximated plants at the test setup is relatively low. The time responses are however comparable to the results from the simulation model. An important constraint for the controlled system is that slip cannot be controlled under all operating conditions. At low variator speeds and low loads, the slip controller must be switched off. A decentralized control structure is chosen. Pairing of the in- and outputs is primarily based on the mechanical design of the Empact CVT and are supported by a interaction analysis. The controllers are designed using a sequential loop closing procedure, in which the slip loop is closed last, such that stability of other loops is guaranteed independent of the switching of the slip controller. Using manual loop-shaping, decentralized lead-lag controllers are designed. Nominal stability and performance can be guaranteed. To obtain robust performance, gain scheduling of the slip controller is implemented. Resulting closed loop bandwidth is 8-10 [Hz] for both the ratio and slip control loops. Because the slip dynamics is not well defined at low or zero variator speeds, the slip controller is partly switched off below 2 [km/h]. Both the simulation model and the experimental setup show very good results for disturbance rejection and tracking performance. Torque disturbances of up to 100 [Nm], applied at the secondary variator shaft, can be suppressed within 0.2 [sec] for all ratios. The ratio tracking error is very small compared to conventional CVT systems. Experimental evaluation of the Empact CVT at the test rig showed that the average power consumption of the Empact CVT on the FTP72 cycle is 155 [W], whereas conventional hydraulically actuated CVTs consume over 400 [W] on the average at this drive cycle. Efficiencies of 90 [%], which is close to the maximum efficiency of the Empact CVT, are reached during these experiments. Evaluation of the Empact CVT in an Audi A3 2.0 FSI shows similar performance. Overall, an efficiency improvement of up to 10 [%] is obtained with the Empact CVT compared to a comparable size hydraulically actuated CVT

    Development of a piezoelectric multi-axis stage based on stick-and-clamping actuation technology

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    This paper presents the design, analysis and fabrication of a piezoelectric multi-axis stage based on a new stick-and-clamping actuation technology for miniaturized machine tool systems, referred to as meso-scale machine tool (mMT) systems. In the stick-and-clamping actuation system, shearing/expanding piezoelectric actuators, an inertial mass and an advanced preload system are configured innovatively to generate the motion of an inertial mass. There are two operating modes in the stick-and-clamping actuation technology: (1) stick mode and (2) clamp mode. In stick mode, the ‘slow’ deformation of the shearing piezoelectric actuators drives an inertial mass, which is located on the tips of the shearing piezoelectric actuators, by means of the friction force at their contact interface. On the other hand, in clamp mode, the expanding piezoelectric actuators provide the clamping force to an inertial mass when the rapid backward deformation of the shearing piezoelectric actuators occurs. The stick-and-clamping actuation technology also enables two-degrees-of-freedom (DOF) motion of an inertial mass in a single plane by perpendicularly stacking two shearing piezoelectric actuators. The 2-DOF piezoelectric multi-axis stage is developed on the basis of the stick-and-clamping actuation technology, and the dynamic and static performance analyses are conducted. The LuGre friction model for the contact interfaces is introduced, and their dynamic behaviours are characterized. In the open-loop static performance test, linear, diagonal and circular motions of the developed piezoelectric multi-axis stage are generated, and their performances are evaluated. The dynamic characteristics and static performances of the developed 2-DOF piezoelectric multi-axis stage show its applicability and effectiveness for the precision positioning system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58149/2/sms7_6_040.pd

    METHODOLOGY OF SYNTHESIS OF PACKING MACHINES FOR FOOD PRODUCTS BASED ON MULTICRITERIAL ANALYSIS

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    The complex of technical means for optimization synthesis of assembling of a packing machine of separate functional modules has been developed. The method of synthesis of a packing machine, based on criterial assessment of separate functional modules (FM), combined by two main assessment groups, has been offered. FM may be selected and calculated by the program of consumption, based on the overall equipment effectiveness (OEE) criterion. An example of synthesis, based on the offered method, takes into account variants of choice of ready functional modules, based on the hierarchic structure of a module of roll packing material supply. The method takes into account the systemic approach to analysis of equipment constructions for packing fine-piece and piece food products in a consumption package. The synthesis of FM assembling as conceptual models, abstract ones, reflecting the construction structure and connections between separate elements – functional devices (FD) – has been offered. The optimal assembling of the functional device in the structure of the functional module of roll packing material supply has been determined. As a result of solving this problem, a FM1 prototype has been created. At conducting the comparative analysis with the existent equipment, the automatic functional device has been modeled. The use of the OEE criterion with joint properties that reflects the generalized assessment of a packing machine or functional module with a maximin (minimax) criterion by the compromise principle has been substantiated. The analysis is grounded on the idea of optimality of each module or device of the machine for packing food products at adding each next functional module to its composition. The program of assessment calculation of the package equipment with the complex assessment criterion OEE for different assembling of FMi machines for packing piece and fine-piece products has been developed. The FM of roll film material supply with using a microprocessor managing device that maintains a sinusoidal law of movement of a stretching roll of the packing machine has been developed. Optimal characteristics of the technical system have been determined. Results, obtained at processing experimental data, confirm adequacy of the offered method for assessing assembling solution
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