Nghiên cứu hệ thống lái steer by wire điện tử thủy lực TT TIENG ANH

MINISTRY OF EDUCATION AND TRAINING UNIVERSITY OF TRANSPORT AND COMMUNICATIONS NGUYEN XUAN TUAN RESEARCH ON ELECTRO – HYDRAULIC STEER BY WIRE SYSTEM Major: Mechanical dynamic engineering Code No: 9520116 SUMMARY OF THESIS FOR DOCTOR OF ENGINEERING HÀ NỘI - 2021 This thesis is completed at: University Of Transport And Communications Scientific Advisers: Associate Prof Dr Nguyen Van Bang Associate Prof Dr Đinh Thi Thanh Huyen Opponent 1: Opponent 2: Opponent 3: This thesis will be defended at Universitarian dissertation Committee at University of Transport and Communications: At……………………… 2021 The thesis can be found at: - National Library - Library of University of Transport and Communications INTRODUCTION The urgency of the research Steer-by-wire (SBW) system is one of the systems that apply electronic technology Recently, many scientists in the country and around the world have been studying this system This modern technology is forecasted to be used on vehicles in big cities in the future Therefore, studying the SBW system has scientific and practical significance in order to grasp advanced technologies in the world  Objects, scope of the research: This is theoretical research and experimental research to convert hydraulic power steering system to electro - hydraulic SBW system on HINO 300 Series trucks  Scientific significance of the study: - Completing the conversion of hydraulic power steering to electro - hydraulic SBW systems on HINO 300 Series truck vehicle - Building a dynamic and a simulation model of the electro hydraulic SBW system which is suitable for the research object, achieving the required accuracy - Researching appropriate control methods, building control laws Design and manufacture an industrial controller that works stably on the research object  Practical significance of the study: - The electro - hydraulic SBW system mounted on the HINO 300 Series is an industrial product that has been tested in many operating modes - Research results can be used for teaching, scientific research, technology transfer - Opening a new research direction on the conversion from normal car steering system to SBW system CHAPTER OVERVIEW OF THE RESEARCH 1.1 Steering system with rotation and directional stability In some cases, it is safer to use the steering system instead of the brakes because steering creates less friction between the tires and the road When the rear tire has reached the limit of grip, the only controller is the front wheel, if braking in this situation often leads to the vehicle losing direction and spinning uncontrollably[13], [15]  1.2 Steer by wire system 1.2.1 Technical specifications of SBW system SBW systems have been studied at present from Figure 1.9 to Figure 1.11: Fig 1.9: Steer by wire - electric motors Fig 1.10: Steer by wire - electric motors Fig 1.11: Steer by wire - Hydraulic assist Conversion from normal steering system to SBW system Instead of using a mechanical steering shaft to drive the steering mechanism, the SBW system uses a steering actuator consisting of motor to create the feeling, motor to rotate the steering mechanism and the steering gear Electronic control as shown in Figure 1.12 1.2.2 Fig 1.12: Conversion from conventional system 1.3 Research in the country and in the world 1.3.1 Research in the country: - Research of Author Tran Van Loi [1]÷[6] - Research of Author Nguyen Ba Hai [20] 1.3.2 Research in the world:  Research on model and dynamics of steer by wire system: Author Sheikh Muhammad Hafiz fahami1 [21] Author Paul Yih, J Christian Gerdes [22]; Author's research Eid S Mohamed, Saeed A Albatlan [23]  Research on control: Author Paul Yih [13]; Author A dem Kader (SBW) [24]; Author Jack J Kenned, Professor V.R Patil [25]; Author Chunyan Wang, Dong Zhou, Wanzhong Zhao, Xiaoyue Gu [26]; Author Salem Haggag, David Alstrom, Sabri Cetinkunt, and Alex Egelja [27]; Author Yixin Yao [28]; Author Se-Wook Oh, Ho - chol CHAE, Seok – Chan YUN [29]; Author Swinburne University, Melbourne, Úc [30]; Author Sheikh Muhamad Hafiz [21]  Research on feedback: Author Se Wook Oh [29]; Author F.Bolourchi [32]; Author Ba-Hai Nguyen, Jee-Hwan Ryu [20]; Author Emad Mehdizadeh, Mansour Kabganian, and Reza Kazemi [34]; Author Andrew Liu Stacey Chang[35]; Author Paul Jih [13] 1.4 Objectives, content and research methods: 1.4.1 Research Objectives Research on converting the normal steering system with hydraulic assistance to the electro - hydraulic SBW system on truck vehicles 1.4.2 Research content The thesis has 04 chapters: - Chapter Overview of the research - Chapter Building a hydraulic model and a simulation model of the electro - hydraulic SBW system - Chapter Design of controller for electro - hydraulic SBW system - Chapter Experimental research on HINO 300 Series 1.4.3 Research Methods Theoretical and experimental research:  Theoretical research: - Building dynamic and simulation models of electro - hydraulic SBW system - Build control law for the actuators  Experimental research: Conducted on HINO 300 Series to get input data for theoretical model and model verification 1.5 Conclusion - Analyzed and evaluated the existing research works of domestic and foreign authors; Stated the outstanding problems; Point out the problems that the thesis needs to focus on solving - The research method and content of the thesis have been identified CHAPTER BUILDING DYNAMICS AND SIMULINK MODEL OF THE ELECTRO – HYDRAULIC SBW SYSTEM 2.1 Theoretical basis The SBW system is a mechanical system with many degrees of freedom and complex linkage, in dynamical models often include elements with mass and connections To build a mathematical model, the thesis uses Lagrange equations of type 2, Dalambe's principle Then the equation of motion will be established on the basis of taking the sum of the moments and forces acting on the mechanical system [7] 2.2 Building dynamics model 2.2.1 Assumptions The joints of the mechanical model have mass at the center of gravity; The stiffness and drag coefficient are constant; The speed of the car is constant; Steering wheel rotation speed is constant; Treat the hydraulic system as adiabatic and isothermal; The flow rate coefficient is constant; The output pressure of the hydraulic pump is constant; power system with stable source voltage; The stator's flux remains unchanged; The torque coefficient and the electromotive force of the motor remain unchanged Fig 2.4: Dynamic model of electro - hydraulic SBW system The physical relationship between the sub-models in the electro hydraulic SBW steering system is presented in Figure 2.5 Fig 2.5: Diagram of the physical relationship between the sub-models in the electro-hydraulic SBW system 2.2.2 Hydraulic power steering system The hydraulic power steering system is modeled as Figure 2.6[36]÷[39] Fig 2.6 Dynamic model of hydraulic system (2.25) 𝐹𝐵 = 𝐴𝑝 𝑃𝐿 2.2.3 DC motor Model of armature of DC motor as shown in Figure 2.7 Fig 2.7: Model of armature of DC motor Equation (2.36) of the electric motor: (2.36) 𝐽𝑚 𝜃̈𝑚 (𝑡) + (𝐵𝑚 + 𝐾𝑏 𝐾𝑚 /𝑅)𝜃̇𝑚 (𝑡) = (𝐾𝑚 /𝑅)𝑉(𝑡) − 𝜏𝑙 (𝑡)/𝑖𝑚 2.2.4 Front wheel driver The drag moment is related to the wheel alignment angles with the road surface, as shown in Figure 2.8[34], is determined by the formula (2.40): Fig 2.8: Guide wheel assembly model 𝑇𝐹_𝐺 = (𝑡𝑝 + 𝑟 𝑡𝑎𝑛𝑣)𝑐𝑜𝑠√𝜆2 + 𝑣 𝐹𝑦𝑓 + 𝑑 𝑠𝑖𝑛𝜆 𝑠𝑖𝑛𝛿 𝐹𝑧𝑓 2.2.5 Steering wheel (2.40) The dynamic model of the steering wheel is shown in Figure 2.9 The differential equation is represented by (2.41) and (2.42) Fig 2.9: Dynamic model of the steering wheel 𝜃̇𝑚1 𝜃𝑚1 ) − 𝐾𝑠𝑤 (𝜃𝑠𝑤 − ) 𝑖𝑚1 𝑖𝑚1 + 𝑇𝑠𝑤 − 𝑇𝐹−𝑆𝑊 + 𝑇𝑐1 𝐶𝑠𝑤 𝜃̇𝑚1 𝐾𝑠𝑤 𝜃𝑚1 = −𝐵𝑚1 𝜃̇1 + (𝜃̇𝑠𝑤 − )+ (𝜃𝑠𝑤 − ) 𝑖𝑚1 𝑖𝑚1 𝑖𝑚1 𝑖𝑚1 𝐾𝑑𝑐1 𝑇𝑐1 + 𝑉𝑚1 −𝑇𝐹−𝐺 − 𝑅1 𝑖𝑚1 𝐽𝑠𝑤 𝜃̈𝑠𝑤 = −𝐵𝑠𝑤 𝜃̇𝑠𝑤 − 𝐶𝑠𝑤 (𝜃̇𝑠𝑤 − 𝐽𝑚1 𝜃̈𝑚1 (2.41) (2.42) 2.2.6 Steering actuator Steering actuator dynamic model is shown in Figure 2.10 [36] The differential equation is represented by (2.43) ÷ (2.54) Fig 2.10: Steering actuator dynamic model 𝐶𝑚2 𝜃̇𝑚2 𝐾𝑚2 𝜃𝑚2 ( − 𝜃̇𝑡𝑏 ) − ( − 𝜃𝑡𝑏 ) 𝑖𝑚2 𝑖𝑚2 𝑖𝑚2 𝑖𝑚2 𝐾𝑑𝑐2 𝑇𝑐2 + 𝑉 (𝑡)−𝑇𝐹𝑅𝑚2 − 𝑅2 𝑚2 𝑖𝑚2 𝐽𝑚2 𝜃̈𝑚2 = −𝐵𝑚2 𝜃̇𝑚2 − (2.43) 𝐽𝑡𝑏 𝜃̈𝑡𝑏 = −𝐶𝑡𝑏 (𝜃̇𝑡𝑏 − 𝜃̇𝑝 ) − 𝐾𝑡𝑏 (𝜃𝑡𝑏 − 𝜃𝑝 ) + 𝜃̇𝑚2 − 𝜃̇𝑡𝑏 ) + 𝐾𝑚2 ( − 𝜃𝑡𝑏 ) −𝑇𝐹𝑅_𝑡𝑏 +𝑇𝑐2 𝑖𝑚2 𝑥̇ 𝑟 𝑥𝑟 𝐽𝑝 𝜃̈𝑝 = −𝐶𝑝 (𝜃̇𝑝 − ) − 𝐾𝑝 (𝜃𝑝 − ) + 𝐶𝑡𝑏 (𝜃̇𝑡𝑏 − 𝜃̇𝑝 ) 𝑁 𝑁 + 𝐾𝑡𝑏 (𝜃𝑡𝑏 − 𝜃𝑝 )−𝑇𝐹𝑅−𝑃 𝑚𝐻 𝑥̈ 𝐻 = −𝐶𝑉 (𝑥̇ 𝐻 − 𝑥̇ 𝑣 ) − 𝐾𝑉 (𝑥𝐻 − 𝑥𝑣 ) + 𝐹𝐹𝑅−𝐻 −𝐹𝐵 𝐶 𝑚𝑅 𝑥̈ 𝑟 = 𝑝 (𝜃̇𝑃 − 𝑥̇ 𝑟 ) − 𝐶𝑇𝑅−𝐿 (𝑥̇ 𝑟 − 𝑙𝜃̇𝐹𝑊−𝐿 ) − 𝐶𝑇𝑅−𝑅 (𝑥̇ 𝑟 − 𝐶𝑚2 ( (2.44) 𝜃𝑚2 𝑖𝑚2 𝑁 (2.45) (2.46) (2.47) 𝑁 𝐾 𝑙𝜃̇𝐹𝑊−𝑅 ) + 𝑝 (𝜃𝑃 − 𝑥𝑟 ) − 𝐾𝑇𝑅−𝐿 (𝑥𝑟 − 𝑙𝜃𝐹𝑊−𝐿 ) − 𝑁 𝑁 𝐾𝑇𝑅−𝑅 (𝑥𝑟 − 𝑙𝜃𝐹𝑊−𝑅 ) + 𝐹𝐵 − 𝐹𝐹𝑅−𝐻 𝐽𝐹𝑊−𝐿 𝜃̈𝐹𝑊−𝐿 = 𝑙𝐶𝑇𝑅−𝐿 (𝑥̇ 𝑟 − 𝑙𝜃̇𝐹𝑊−𝐿 ) − 𝐶𝑇𝑖−𝐿 (𝜃̇𝐹𝑊−𝐿 − 𝜃̇𝐶𝑃−𝐿 ) + 𝑙𝐾𝑇𝑅−𝐿 (𝑥𝑟 − 𝑙𝜃𝐹𝑊−𝐿 ) − 𝐾𝑇𝑖−𝐿 (𝜃𝐹𝑊−𝐿 − 𝜃𝐶𝑃−𝐿 )−𝑇𝐹𝐿−𝐾 𝐽𝐹𝑊−𝑅 𝜃̈𝐹𝑊−𝑅 = 𝑙𝐶𝑇𝑅−𝑅 (𝑥̇ 𝑟 − 𝑙𝜃̇𝐹𝑊−𝑅 ) − 𝐶𝑇𝑖−𝑅 (𝜃̇𝐹𝑊−𝑅 − 𝜃̇𝐶𝑃−𝑅 ) + 𝑙𝐾𝑇𝑅−𝑅 (𝑥𝑟 − 𝑙𝜃𝐹𝑊−𝑅 ) − 𝐾𝑇𝑖−𝑅 (𝜃𝐹𝑊−𝑅 − 𝜃𝐶𝑃−𝑅 )−𝑇𝐹𝑅−𝐾 𝐽𝐶𝑃−𝐿 𝜃̈𝐶𝑃−𝐿 = 𝐶𝑇𝑖−𝐿 (𝜃̇𝐹𝑊−𝐿 − 𝜃̇𝐶𝑃−𝐿 ) + 𝐾𝑇𝑖−𝐿 (𝜃𝐹𝑊−𝐿 − 𝜃𝐶𝑃−𝐿 )−𝑇𝐹𝐿−𝐺 𝐽𝐶𝑃−𝑅 𝜃̈𝐶𝑃−𝑅 = 𝐶𝑇𝑖−𝑅 (𝜃̇𝐹𝑊−𝑅 − 𝜃̇𝐶𝑃−𝑅 ) + 𝐾𝑇𝑖−𝑅 (𝜃𝐹𝑊−𝑅 − 𝜃𝐶𝑃−𝑅 )−𝑇𝐹𝑅−𝐺 𝑚𝐹𝑊−𝐿 𝑥̈ 𝐹𝑊−𝐿 = −𝐶𝑆−𝐿 (𝑥̇ 𝐹𝑊−𝐿 − 𝑥̇ 𝑉 ) − 𝐶𝑇−𝐿𝐴 𝑥̇ 𝐹𝑊−𝐿 − 𝐾𝑆−𝐿 (𝑥𝐹𝑊−𝐿 − 𝑥𝑉 ) − 𝐾𝑇−𝐿𝐴 𝑥𝐹𝑊−𝐿 𝑚𝐹𝑊−𝑅 𝑥̈ 𝐹𝑊−𝑅 = −𝐶𝑆−𝑅 (𝑥̇ 𝐹𝑊−𝑅 − 𝑥̇ 𝑉 ) − 𝐶𝑇−𝐿𝐴 𝑥̇ 𝐹𝑊−𝑅 − 𝐾𝑆−𝑅 (𝑥𝐹𝑊−𝑅 − 𝑥𝑉 ) − 𝐾𝑇−𝐿𝐴 𝑥𝐹𝑊−𝑅 𝑚𝑉 𝑥̈ 𝑉 = 𝐶𝑉 (𝑥̇ 𝐻 − 𝑥̇ 𝑉 ) + 𝐶𝑆−𝐿 (𝑥̇ 𝐹𝑊−𝐿 − 𝑥̇ 𝑉 ) + 𝐶𝑆−𝑅 (𝑥̇ 𝐹𝑊−𝑅 − 𝑥̇ 𝑉 ) + 𝐾𝑉 (𝑥𝐻 − 𝑥𝑉 ) + 𝐾𝑆−𝐿 (𝑥𝐹𝑊−𝐿 − 𝑥𝑉 ) + 𝐾𝑆−𝑅 (𝑥𝐹𝑊−𝑅 − 𝑥𝑉 ) (2.48) (2.49) (2.50) (2.51) (2.52) (2.53) (2.54) 2.2.7 Dynamic model of changing direction of car motion Consider the motion model of the car in the road plane as shown in Figure 2.11 [34] with 𝑣𝑥 = 𝑥̇ = 𝑐𝑜𝑛𝑠𝑡, The differential equation is represented by (2.58) and (2.59) 10 Fig 2.13: Simulation dynamic of Steering actuator dynamic 2.4 Conclusion - Built a dynamic model for the electro-hydraulic SBW system, in which there are sub-models: Hydraulic power steering system, DC motor, guide wheel, steering wheel, Steering actuator, model changing direction of car movement - Built a block diagram to simulate the dynamics of the steering wheel and the actuator using Matlab/Simulink software CHAPTER CONTROLLER DESIGN FOR ELECTRO – HYDRAULIC SBW SYSTEM 3.1 Slide mod control (SMC) overview  Design steps slide mod controller orbit tracking: - Step 1: Represent the I/O relationship of the nonlinear object: (3.1) 𝑦 (𝑛) = 𝑓(𝑥) + 𝑔(𝑥)𝑢 - Step 2: Select the sliding surface (3.2) 𝜎 = 𝑒 (𝑛−1) + 𝑘1 𝑒 (𝑛−2) + ⋯ + 𝑘𝑛−2 𝑒̇ + 𝑘𝑛−1 𝑒 Inside 𝑘𝑖 choose so that (3.3) ∆(𝑠) = 𝑠 𝑛−1 + 𝑘1 𝑠 𝑛−2 + ⋯ + 𝑘𝑛−2 𝑠 + 𝑘𝑛−1 - Step 3: Write the slide controller expression: (3.4) (𝑛) 𝑢= [−𝑓(𝑥) − d + 𝑦𝑑 + 𝑘1 𝑒 (𝑛−1) + +𝑘𝑛−2 ë 𝑔(𝑥) + 𝑘𝑛−1 ė + 𝐾𝑠𝑖𝑔𝑛(σ) Inside K>0 The larger K is the faster σ → - Step 4: Design a low-pass filter of the input signal to ensure that the differentiable 𝑦𝑑 (𝑡) calibration signal is suppressed to the nth order 3.2 Controller design for electro - hydraulic SBW system by SMC 3.2.1 Controller design for Steering actuator 11  Represent the I/O relationship of the nonlinear object: 𝑥̇ = 𝐴𝑥 + 𝐵𝑢 + 𝑤  Select the sliding surface: (3.59) 𝑠2 = 𝑒̇2 + 𝑘2 𝑒2  Write the slide controller expression: 𝑅 𝐶 𝑥 (3.67) 𝑉𝑚2 = [𝑖𝑚2 𝐽𝑚2 𝜃̈𝑠𝑤 + 𝐵𝑚2 𝑥6 + 𝑚2 ( − 𝑥8 ) + 𝑘𝑚2 𝑥5 ( 𝑖𝑚2 𝑖𝑚2 𝑘𝑑𝑐2 𝑖𝑚2 𝑖𝑚2 − 𝑥7 ) + 𝑘2 𝐽𝑚2 (𝑖𝑚2 𝑥2 − 𝑥6 ) + 𝑘2 𝑠𝑖𝑔𝑛(𝑠2 )] 3.2.2 Controller design for Steering wheel  Represent the I/O relationship of the nonlinear object: 𝑥̇ = 𝐴𝑥 + 𝐵𝑢 + 𝑤  Select the sliding surface: 𝑠1 = 𝑒1̇ + 𝑘1 𝑒1  Write the slide controller expression: 𝑅 𝑉𝑚1 = 𝑘 [𝐽𝑚1 𝑘1 (𝑖𝑚1 𝑥2 − 𝑥4 ) + 𝑖 ((𝐽𝑠𝑤 + 𝑚1 (3.68) (3.69) (3.87) 𝑚1 𝑖𝑚1 𝐽𝑚1 )𝜃̈𝑠𝑤 +𝐵𝑠𝑤 𝑥2 + 𝑖𝑚1 𝐵𝑚1 𝑥4 ) + 𝑘 𝑠𝑖𝑔𝑛(𝑠)] 3.3 Simulation of electro - hydraulic SBW system 3.3.1 Simulation block diagram of electro - hydraulic SBW system Figure 3.10 shows the simulation block diagram of SBW system using Matlab/Simulink software Fig 3.10: Block diagram simulation of SBW system 3.3.2 Simulation of the steering wheel Simulation results: Figure 3.11 show the steering wheel angle 𝜃𝑠𝑤 ; Figure 3.12 show the steering wheel angle DCM1 simulation 𝜃𝑚1 and desire 𝑑 𝜃𝑚1 ; Figure 3.13 show the error 𝑒1 DCM1 simulation and desire angle: 12 𝑒1𝑚𝑎𝑥 = 0.1682 (rad), RMS 𝑒1 = 0.098 (rad); Figure 3.14 show control voltage DCM1: RMS = 5,7225 (V), max = 9,8(V) Fig 3.11: Graph showing steering wheel angle Fig 3.12: Graph showing DCM1 simulation and desire angle Fig 3.13: error 𝑒1 simulation and desire angle Fig 3.14: Graph showing DCM1 control voltage 3.3.3 Simulation of the steering actuator Simulation results: Figure 3.15 show the simulation angle 𝜃𝑚2 and desire 𝑑 𝜃𝑚2 ; Figure 3.16 show error 𝑒2 : 𝑒2𝑚𝑎𝑥 =0,0273 (rad), RMS𝑒2 = 0,0105 𝑑 (rad); Figure 3.17 show simulation angle 𝜃𝐹𝑊 and desire 𝜃𝐹𝑊 ; Figure 3.18 show error 𝑒3 : 𝑒3𝑚𝑎𝑥 = 0.009 (rad), RMS𝑒3 = 0.0053 (rad); Figure 3.19 show DCM2 control voltage: max = 9,8 (V), RMS = 5,7225 (V); Figure 3.20 show hydraulic power 𝐹𝐵 : RMS/max = 401,88/ 807,47 (N); 13 Fig 3.15: Graph showing the simulation angle and deside Fig 3.16: Graph showing error 𝑒2 Fig 17: Graph showing simulation angle and deside angle Fig 3.18: Graph showing error 𝑒3 Fig 3.19: Graph showing DCM2 control voltage 14 Fig 3.20: Graph showing hydraulic power 𝐹𝐵 3.3.4 Simulation of changing direction of car movement Figure 3.21 show steering wheel angle; Figure 3.22 shows the simulated horizontal body displacement at three speeds 5m/s, 10 m/s, 15 m/s; Figure 3.23 shows the simulated body rotation angle at three speeds 5m/s, 10 m/s, 15 m/s; Figure 3.24 shows the drag torque of the steering system Fig 3.21: Graph showing steering wheel angle Fig 3.22: Graph showing horizontal body displacement Fig 3.23: Graph showing body rotation angle Fig 3.24: Graph showing the drag torque 15 Simulation at max speed: Vmax = 30,5 m/s (109 km/h): Fig 3.25: Graph showing horizontal body displacement Fig 3.26: Graph showing body rotation angle Fig 3.27: Graph showing the drag torque Conclusion - Selected the SMC control method and studied the theory of this method for application in the thesis - Built a control model for the whole system, including: Control model to create driving feeling and control model to act as a guide CHAPTER EXPERIMENTAL RESEARCH 4.1 Research purpose and methods  The purpose of the experiment on cars HINO 300 Series with hydraulic power steering: Measure, evaluate parameters and determine the angular transmission ratio of the steering system  Purpose of experiment on car HINO 300 Series with electro hydraulic SBW system: - Evaluate the stable and reliable operation of the electro - hydraulic SBW system designed on the HINO 300 Series in static modes, operating on traffic roads, turning around with the smallest turning radius - Provide 3.4 16 input data for the theoretical model for testing, the theoretical model for the electro - hydraulic SBW steering system  Directly tested on HINO 300 Series cars in static modes, operating on internal roads, turning around with the smallest turning radius 4.2 Experimental study with hydraulic power steering system 4.2.1 Preparation steps  The test truck vehicle is a HINO 300 Series  Experimental equipment and tools: Angle measuring device for guiding wheel; Steering wheel dirt gauge 4.2.2 Implementation method Experiment with hydraulic power steering system: Measure steering wheel angle θ, guide wheel rotation angle α, β 4.2.3 Experimental results Figure 4.7 show steering wheel and wheel guide angle when driving on the right; Figure 4.8 show steering wheel and wheel guide angle when driving on the left Góc quay BX DH (độ) 40 bánh 30 bánh 20 10 0 90 180 270 360 450 540 630 720 740 Góc quay vành lái (độ) Góc quay BXDH (độ) Fig 4.7: Relation of steering wheel and wheel guide angle 40 bánh 30 bánh 20 10 90 180 270 360 450 540 630 660 Góc quay vành lái (độ) Góc quay  (độ) Fig 4.8: Relation of steering wheel and wheel guide angle Fig 4.10 show relation angle , and : 30 thực tế 20 lý thuyết 10 Góc quay  (độ) Fig 4.10: Relation angle , and  17  The gear ratio of the steering system is according to the following formula: 2. vl ihtl   24.7   4.3 Electro-hydraulic SBW system conversion 4.3.1 Survey, measure parameters on trucks HINO 300 Series The process of surveying and measuring the parameters of the steering system and surveying to plan the conversion of the steering system on the HINO 300 Series was carried out at HINO Vietnam and the University of Transport 4.3.2 Steering wheel conversion Figure 4.13 show steering wheel after making Fig 4.13: Show steering wheel 4.3.3 Steering actuator conversion Figure 4.15 show steering actuator after making Fig 4.15: Steering actuator 4.3.4 Calculation and testing of working parameters of SBW electro - hydraulic system on HINO 300 Series truck cars  Electro - hydraulic SBW steering gear ratio (4.2) 𝑖𝑡 = 16,33.1,86.24,7 = 750,2  Calculation of drag moment: Tc=2.(9,59+302,97).1,15 = 718,89 (Nm) (4.17)  Check DCM2 motor parameters: Tch= 1,83.30,34.24,7.0,7 = 959,98 (Nm) (4.24) 18 4.3.5 Design of the controller for the electro – hydraulic SBW system Control diagram of the system as shown in Figure 4.18 Fig 4.18: Control diagram of the system 4.3.6 Results display and data storage Electro - hydraulic SBW system controller with computer to display and store results 4.4 Experiment with electro - hydraulic SBW system 4.4.1 Preparation steps  Experimental truck vehicle: HINO 300 Series truck vehicle with electro - hydraulic SBW system  Experimental location: Using internal roads in the University of Transport for experimentation  Experimental equipment: GPS device and decoder placed in the car connected to the computer via USB port 4.4.2 Experimental results  Experiment in steady state: - Without power hydraulic: Figure 4.55 show steering actuator angle 𝑡𝑛 𝜃𝑚2 𝑖𝑚2 tn and steering wheel angle 𝜃sw ; Figure 4.56 show error 𝑒4 : RMS 𝑒4 = 0,0978 (rad), 𝑒4 𝑚𝑎𝑥 = 0,15 (rad); Figure 4.57 show tn DCM2 control voltage 𝑉m2 max = 10 (V) Fig 4.55: Graph showing the steering actuator and steering wheel angle 19 Fig 4.56: Graph showing the error 𝑒4 Fig 4.57: Graph showing the DCM2 control vontage - With power hydraulic: Figure 4.59 show steering actuator angle 𝑡𝑛 𝜃𝑚2 𝑖𝑚2 tn and steering wheel angle 𝜃sw ; Figure 4.60 show error 𝑒4 : RMS 𝑒4 = 0,1 (rad), 𝑒4 𝑚𝑎𝑥 = 0,17 (rad); Figure 4.61 show DCM2 control voltage Fig 4.59: Graph showing the steering actuator and steering wheel angle Fig 4.60: Graph showing the error 𝑒4 Fig 4.61: Graph showing the DCM2 control vontage 20  Experiment on roads: Figure 4.62 show steering actuator angle 𝑡𝑛 𝜃𝑚2 𝑖𝑚2 and steering wheel tn angle 𝜃sw ; Figure 4.63 show error 𝑒4 : RMS 𝑒4 = 0,0184 (rad), 𝑒4 𝑚𝑎𝑥 = tn 0,1189 (rad); Figure 4.64 show DCM2 control voltage 𝑉m2 max = (V) Fig 4.62: Graph showing the steering actuator and steering wheel angle Fig4.63: Graph showing the error 𝑒4 Fig 4.64: Graph showing the DCM2 control vontage  Experimenting with car motion trajectories: Figure 4.65 show car motion trajectories; Figure 4.66 shows the rotating orbit with the minimum turning radius: Fig 4.65: Motion trajectory with electro - hydraulic SBW system 21 4.5 Fig 4.66: Rotating orbit with minimum turning radius Verifying the theoretical model with experiment  Without power hydraulic: tn Figure 4.67 show steering wheel angle 𝜃sw ; Figure 4.68 show steering actuator simulation 𝑙𝑡 𝜃𝑚2 𝑖𝑚2 and experiment angle 𝑡𝑛 𝜃𝑚2 𝑖𝑚2 ; Figure 4.69 show error 𝑒5 : RMS𝑒5 = 0,0978 (rad), 𝑒5 𝑚𝑎𝑥 = 0,15 (rad) Fig 4.67: Graph showingsteering wheel angle Fig 4.68: Steering actuator simulation and experiment angle Fig 4.69: Graph showing error 𝑒5  With power hydraulic: 𝑡𝑛 Figure 4.70 show steering wheel angle 𝜃𝑠𝑤 ; Figure 4.71 show steering actuator simulation 𝑙𝑡 𝜃𝑚2 𝑖𝑚2 and experiment angle 𝑡𝑛 𝜃𝑚2 𝑖𝑚2 ; Figure 4.72 show error 𝑒5 : RMS𝑒5 = 0,0338 (rad), 𝑒5 𝑚𝑎𝑥= 0,157 (rad) 22 Fig 4.70: Graph showingsteering wheel angle Fig 4.71: Steering actuator simulation and experiment angle Fig 4.72: Graph showing error 𝑒5 Conclusion - Successfully converted hydraulic power steering system into electro-hydraulic SBW system on Hino 300 Series trucks vehicle The steering system works stably in static modes, moving at a speed of 5÷ 10 km/h on the road - The experimental results show that the steering system works stably and reliably in the working states with error 𝑒4 → - The difference between the theoretical and experimental model 𝑒5 →0 , showing that the theoretical model is reliable and accurate GENERAL CONCLUSIONS - The thesis with the topic "Research on electro -hydraulic SBW system" is a scientific work in line with the development trend of the automobile industry It includes the following contents: An overview study of the electro -hydraulic SBW system; Building a dynamic model of the electro-hydraulic SBW system; Building simulation models; Select control method; Experimental study - Dynamic model includes model of mechanical, electrical and hydraulic elements which are built up separate assemblies The 4.6 23 simulation model uses Matlab/Simulik software with input parameters taken from experimental results and reference documents - Successfully converted hydraulic power steering system into electro-hydraulic SBW system on Hino 300 Series truck vehicle The steering system works stably in static modes and moving at a speed of 5÷ 10 km/h on the road  Contributions of the thesis: - Successfully converted the hydraulic power steering system of trucks to the electro - hydraulic SBW system The vehicle-mounted system operates stably and reliably in operating modes on traffic roads at a speed of ÷ 10 km/h - Researched to create driving feeling for the electro - hydraulic SBW system including: Creating driving feeling torque; Limiting the steering wheel; Automatically return the steering wheel to the neutral position - The products of the thesis such as: theoretical models, software, mechatronic devices, etc can be served for further researches on this system RECOMMENDATIONS AND DIRECTIONS FOR FURTHER RESEARCH  Recommendation: It is recommended that the vehicle be tested on the test ground with a higher speed and load as prescribed  Further research directions: - Researching to put power steering pump driven by electric motor, common control system with electro -hydraulic SBW system - Incorporating the self-diagnostic system of the steering system into the general diagnostic system of the vehicle - Study the backup safety plan in case of having electric problems - Research to automatically change the gear ratio of the steering system basing on actual operating conditions THE RESEARCH PAPERS OF AUTHOR Trần Văn Lợi, Nguyễn Văn Bang, Trần Văn Như, Nguyễn Xuân Tuấn (2016), “Mô chuyển ô tô sử dụng hệ thống lái Steer by wire”, Tạp chí khoa học & công nghệ số 33, tháng 4/2016 Nguyễn Xuân Tuấn, Nguyễn Văn Bang, Trần Văn Như, Đinh Thị Thanh Huyền (2016), “Thiết kế điều khiển lái cho hệ thống lái không trụ lái (Steer by wire) điện tử - thủy lực”, Tạp chí Cơ khí Việt Nam số đặc biệt, tháng 9/2016 Nguyễn Xuân Tuấn, Nguyễn Văn Bang, Trần Văn Như, Lê Văn Anh, Chu Đức Hùng (2017), “Xây dựng mơ hình hệ thống lái Steer by wire điện tử - thủy lực” , Tạp chí khoa học & cơng nghệ số 38, tháng 2/2017 Nguyễn Xuân Tuấn, Nguyễn Văn Bang, Trần Văn Như, Nguyễn Thế Anh (2018), “Ứng dụng Matlab/Simulink mơ hình hóa mô động lực học hệ thống thủy lực trợ lực lái tơ”, Tạp chí khoa học & công nghệ số 47, tháng 8/2018 N X Tuan, H T Dinh, and N V Bang (2019), “Research on Dynamic Modelling for Hydraulic Power Automotive Steering Systems with Nonlinear Friction” Springer Nat Lect Notes Netw Syst 104 Pp620-627, p (Scopus Q4), ISSN:2367-3370, E-ISSN: 2367-3389, Dec 2019 ... “Xây dựng mơ hình hệ thống lái Steer by wire điện tử - thủy lực? ?? , Tạp chí khoa học & công nghệ số 38, tháng 2/2017 Nguyễn Xuân Tuấn, Nguyễn Văn Bang, Trần Văn Như, Nguyễn Thế Anh (2018), “Ứng... hệ thống lái không trụ lái (Steer by wire) điện tử - thủy lực? ??, Tạp chí Cơ khí Việt Nam số đặc biệt, tháng 9/2016 Nguyễn Xuân Tuấn, Nguyễn Văn Bang, Trần Văn Như, Lê Văn Anh, Chu Đức Hùng (2017),... thống lái Steer by wire? ??, Tạp chí khoa học & công nghệ số 33, tháng 4/2016 Nguyễn Xuân Tuấn, Nguyễn Văn Bang, Trần Văn Như, Đinh Thị Thanh Huyền (2016), “Thiết kế điều khiển lái cho hệ thống lái không