• Journal of Sensor Science and Technology
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• v.27 no.2
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• pp.126-131
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• 2018

Unlike the hydraulic power steering (HPS) system, which operates by the high pressure of a fluid obtained from the engine power, the motor-driven power steering (MDPS) system uses an electric motor to steer the wheel without consuming engine power. To steer the wheel with an electric motor, a worm wheel and a worm gear rotating between the steering shaft and motor are required. Any imperfection during the construction of an MDPS system or in a composing part creates noise and vibration, which can be sensed by a driver. To solve the noise and vibration problems, each part must be designed to not resonate with other parts. In this work, we developed the measurement and analysis systems to obtain the noise and the vibration of an automobile MDPS system. A signal analyzer was equipped with a 96 kHz, 24-bit ADC and a 150 MHz digital signal processor. The predetermined threshold value of the vibration in the MDPS system was used to determine the pass/fail, and the results were displayed on the screen. Our system can be used in the fabrication line to swiftly determine any imperfections in the MDPS system construction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5480-5486
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• 2014

Complete novel software for MDPS for the simulation and analysis is proposed for steering engineers. The software, MSAS, which can provide the functionality for MDPS Simulation, Analysis & Synthesis, is based on the steering system model, vehicle model and control logic. As the suppliers provide the control logic as a black box, this software is capable of using any type of black box logic or white box control logic that can be developed by logic designers. In addition, this software will be synthesized with the suppliers' s-function control logic and RMDPS together.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.731-732
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• 2009

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1555-1560
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• 2013

The Column type Motor Driven Power Steering(CMDPS) systems are generally equipped among passenger vehicles ensuring better vehicle safety and fuel economy. In general to analyze systems and to develop a controller a full vehicle model from CarSim developed by Mechanical Simulation Incorporation interacting with MDPS control algorithm from Matlab Simulink was concurrently simulated. This paper describes the development of concurrent simulation technique in detail for analyzing Matlab Simulink MDPS control system with a dynamic vehicle system because the specific method has not been revealed in detail. The steering wheel angle input was evaluated and well compared with proving ground experimental data. The comparisons from concurrent simulation show an effective way to develop and validate the control algorithm. This concurrent simulation capability will be efficiently used for CMDPS performance evaluation and logic tuning as well as for vehicle handling performance.

• Journal of Mechanical Science and Technology
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• v.16 no.2
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• pp.155-164
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• 2002

The power steering system for vehicles is becoming essential for supporting the steering efforts of the drivers, especially for the parking lot maneuver Although hydraulic power steering has been widely used for years, its efficiency is not high enough. The problems associated with a hydraulic howe. steering system can be solved by a motor driven power steering (MDPS) system. In this study, a dynamic model and a control algorithm for the ball screw type of MDPS system have been derived and analyzed by using the method of discrete modeling technology. To improve steering feel and power steering characteristics, two derivative gains are added to the conventional power boosting control algorithm. Through simulations, the effects of the control gain on the steering angle gain were verified in the frequency domain. The steering returnability and steering torque phase lag in on-center handling test were also evaluated in the time domain.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.6
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• pp.201-214
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• 2014

In this paper, we propose a test case generation method adequate to destructive test of the BLDC(Brush Less Direct Current) motor controller used for the MDPS(Motor Driven Power Steering) system embedded in an automobile. The proposed method is a modified CTM(Classification Tree Method). CTM generates test cases assuming that all inputs are equally important. Therefore, it is very hard to generate test cases for extreme situations. To overcome the drawback and generate test cases specialized for destructive test. a modified CTM that compensates the limitation of traditional CTM is proposed. The proposed method has an advantage that it can intensively generate the test scenarios adequate to extreme situations by combining the test cases generated by the transitional CTM the while keeping the merit of the traditional CTM. The test scenarios for destructive test for the MDPS system embedded in a commercial automobile are generated utilizing the proposed method. The effectiveness of the proposed algorithm is verified through the test.

• Electrical & Electronic Materials
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• v.22 no.9
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• pp.19-29
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• 2009

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.5
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• pp.640-650
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• 1998

Pumping performances of a helical molecular drag dump(MDP) and of a radial MDPs are numerically analyzed by using the direct simulation Monte Carlo (DSMC) method. A helical- and radial-MDP have rotating pumping channels cut on a cylinder and on a disk, respectively. For a helical MDP, the present results agree quantitatively with the previously known numerical results. For radial MDPs, both of the Type 1 (having pumping channels cut on the stationary disk) and of the Type 2 (having pumping channels cut on the rotating disk) are analyzed to predict their performances for various parameters, i.e., the radius of curvature center of the channel wall, the depth of the channel, the clearance between housing and disk, and the rotating speed. The results show that the performance of the Type 2 is superior to that of the Type 1, and that for all types the pumping efficiency decreases as the clearance increases. Also, the radial type MDP has larger leakage losses in the direction of pumping channel than does the helical one.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.113-119
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• 2014

For the robust design of Motor Driven Power Steering (MDPS) systems, it is important to consider energy efficiency from every aspect such as system configuration and current flow, etc. If design optimization is not considered, it has many problems on a vehicle. For example, when evaluating steering test, particularly the Catch-up test which turning the steering wheel left or right quickly, steering effort should be increased rapidly. Also a vehicle might have poor fuel efficiency. In this study, it is calculated energy consumption for each component of the steering system and analyzed factors of energy consumption. As a result, this paper redefines a method to estimate steering input torque using characteristics of vehicle electric components and then conducts an analysis of contribution for the Catch-up.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1223-1230
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• 2017

The back emf harmonics of a permanent magnet (PM) synchronous motor is a major source of torque ripple. For torque control applications including column fitted MDPS (motor driven power steering) systems, it is essential to reduce the mechanical vibrations due to torque ripples at low speeds. In this paper, a torque ripple reduction algorithm for interior PM synchronous motors is proposed. The harmonic currents that cancel the $6^{th}$ order torque harmonic are added to the nominal dq currents for MTPA (maximum torque per ampere) operation. The compensated harmonic currents are derived from flux linkage harmonics based on a FFT analysis of the back emf harmonics. Simulation and experimental results verify that the $6^{th}$ order torque harmonic and THD of the torque ripple are reduced by compensating the dq harmonic currents.