• 센서학회지
• /
• 제27권2호
• /
• pp.105-111
• /
• 2018

In this paper, a torque sensor is designed and fabricated to measure the knee joint torque of a walking assist robot for stroke patients. The torque sensor sensing part was modeled on the link of the part connected to the knee joint motor. The torque capacity of the knee joint was calculated by simulation and the size of the torque sensor sensing part was designed using the finite element method. The torque sensor was fabricated by attaching a strain gauge to the sensing part. Characteristic experiments were conducted to characterize the torque sensor, and the torque sensor was calibrated to utilize it for the control of the walking assist robot. As a result of the characteristics test, the reproducibility error and the nonlinearity error of the torque sensor were 0.03% and 0.04%, respectively. Therefore, it is considered that the developed torque sensor can be used to measure the torque applied to the knee joint when walking on a walking assist robot.

• 한국자동차공학회논문집
• /
• 제22권3호
• /
• pp.186-193
• /
• 2014

On-center handling feel indices are the important numerical factors that meaning performance of manuability and stability felt by drivers. They should be considered to suspension design. The major factor that affect to these indices is the shape of assist torque curve. This paper presents the variables that meaning the shape of the assist torque curve and analyze the effect of each variables. And using interaction formulas, it is proposed that the method to extract the variables that satisfy the goal indices. The result of simulation that applied assist torque curve extracted by the method demonstrate the capability of this method with error under 8%.

• 한국자동차공학회논문집
• /
• 제8권4호
• /
• pp.186-193
• /
• 2000

EPS(Electric Power Steering) systems have many advantages over traditional hydraulic power steering systems in space efficiency engine efficiency and environmental compatibility. In this paper an EPS system control logic using a torque map is proposed. The main function of the EPS system is to reduce the steering torque exerted by a driver by assist of an electric motor. Vehcile speed steering torque and steering wheel angle are measured and fed back to the EPS control system where appropriate assist torque is generated to assist the operator's steering effort. Another capability of the EPS system for easy adaptation to different steering feels via simple tuning is demonstrated by the experiments. It will be also verified that the EPS system can also improve damping and return performance of the steering wheel by control of the assist motor.

• 제어로봇시스템학회논문지
• /
• 제16권6호
• /
• pp.566-571
• /
• 2010

EPS (Electric Power Steering) is important device for improving vehicle's dynamics and static performances. This paper deals with simulator design for C-EPS (Colum type-EPS), development assist and returnability control algorithm. First, C-EPS system model was simply designed because EPS system is complex control system that has many unknown variables. These parameters were simplified through assumptions. Second, C-EPS simulator was designed for development of control algorithm. This simulator has SAS (Steering Angle Sensor), dual torque sensor, dual load cell for measuring rack force, dual linear actuator for generating tire force and Data Acquisition System. Using this simulator, control methods ware tested. Third, control algorithm was designed for torque assist and returnability. Assist torque map and returnability torque map were found by lots of simulation test. These torque maps were tuned for EPS actuator control. The simulation result was compared with non-EPS system result. In this research, the C-EPS simulator was designed for development of control algorithm about torque assistant and returnability. Using this simulator, control algorithm was improved.

• 대한기계학회논문집A
• /
• 제38권6호
• /
• pp.593-600
• /
• 2014

본 논문은 농작업 시 농업용 하이브리드 트랙터를 위한 토크 지원 전략을 제안한다. 일반적으로 농업용 트랙터는 베일러, 로타리 등 농작업 종류에 따라 필요한 토크의 크기가 다양하기 때문에 특수목적을 위하여 출력이 큰 트랙터가 필요할 수 있다. 따라서 본 연구에서는 연비개선보다는 작은 모터를 사용하여 특정 농작업에 필요한 적절한 토크 지원을 수행함으로써 동일한 사이즈의 기존 트랙터보다 다양한 농작업을 좀 더 효율적으로 수행할 수 있는 하이브리드 트랙터 개발을 목표로 한다. 이를 위한 토크 지원 전략을 제안하고 상용 차량 시뮬레이터인 Autonomie 를 기반으로 한 하이브리드 트랙터 모델을 이용하였다. 마지막으로 토크 어시스트 전략을 적용한 하이브리드 트랙터와 일반 트랙터에 대한 시뮬레이션을 통해 작업 효율과 연료 사용량을 검증하였다.

• 대한기계학회논문집A
• /
• 제30권6호
• /
• pp.684-690
• /
• 2006

This study proposes and validates a new column type electric power steering system (EPS-TT). It is driven by a uni-directional motor and two electro-magnetic clutches. The assist motor produces assist torque in only one direction and two clutches transmit the torque to the column of steering system in either left or right direction with respect to the steering input. A full order and a reduced order models are developed to evaluate the EPS-TT. Models are also used to investigate the vehicle responses. A PID control logic is designed to control the torque of the assist motor. A driver model is applied to the system and the resulting performances are analyzed. The results show that the performances of the full order model are similar to those of reduced order model. The results also prove that the performances achieved by the EPS-TT are improved compared to those of a conventional EPS-TT across the frequency domain.

• 한국자동차공학회논문집
• /
• 제12권5호
• /
• pp.154-161
• /
• 2004

A new column type electric power steering system (EPS-TT) is proposed in this study. The remarkable features of EPS-TT are its opto-isolated torque sensor and assist torque control methodology. EPS-TT uses a uni-directional motor and two clutches. Full order and simplified models for EPS-TT are developed to evaluate the EPS-TT. A full car model is also used to investigate the vehicle responses. A PID control logic is designed to control the torque of the assist motor. Various sinusoidal inputs are applied to the system and the resulting performances are analyzed. The results prove that the performances achieved by the EPS-TT are improved compared to those of a conventional EPS-TT across the frequency domain. In addition, it is inexpensive and easy to control the motor. The results of the full order steering system model are similar to those simplified model, but the vehicle responses are slightly different.

• 재활복지공학회논문지
• /
• 제9권1호
• /
• pp.81-87
• /
• 2015

파워 어시스트 휠체어(PAW)가 주행방향을 일직선으로 유지하기 위해서는 좌우 휠에 같은 힘이 전달되어야 한다. 하지만 인간은 양쪽 팔 힘이 서로 다르고 항상 균일하게 자신의 힘을 제어하지 못하므로 PAW 운전시 방향보정을 빈번하게 해야 할 수도 있다. 따라서 직선구간에서 PAW의 주행방향을 일정하게 유지하거나 회전구간에서 방향전환을 신속하게하기 위해서는 불균형한 입력토크로부터 사용자의 주행의도를 감지하여 적절한 어시스트 출력토크를 생성하여야 한다. 본 연구에서는 좌우측 push-rim에 가해지는 입력토크 신호간의 시간적 유사성으로부터 사용자의 주행의도를 판단하는 새로운 방식를 제시하고, 이를 이용한 토크밸런스 제어기법을 제안한다. 그리고 주행실험을 통해 제안한 밸런스 제어기의 효용성을 검증하였다.

• 한국자동차공학회논문집
• /
• 제19권1호
• /
• pp.9-16
• /
• 2011

Research on ISA(Integrated Starter/Alternator) receives wide attention as system voltage is increased to 42V Based on requirement of starter and alternator for the conventional vehicle, system requirement and specification are determined. Also to control proposed system, suitable control methods are proposed. Main control issues with ISA are whether torque assist is required and if so how much torque is needed. In this paper, vehicle performance with various control methods and capacity are simulated and simulation results are analyzed. Vehicle performance is analyzed with vehicle simulator. For the simulation, suitable ISA model is also developed.

• 자동차안전학회지
• /
• 제12권3호
• /
• pp.13-19
• /
• 2020

This paper presents steering controller for unintended lane departure avoidance under crosswind using vehicle lateral disturbance estimation. Vehicles exposed to crosswind are more likely to deviate from lane, which can lead to accidents. To prevent this, a lateral disturbance estimator and steering controller for compensating disturbance have been proposed. The disturbance affecting lateral motion of the vehicle is estimated using Kalman filter, which is on the basis of the 2-DOF bicycle model and Electric Power Steering (EPS) module. A sliding mode controller is designed to avoid unintended the lane departure using the estimated disturbance. The controller is based on the 2-DOF bicycle model and the vision-based error dynamic model. A torque controller is used to provide appropriate assist torque to driver. The performance of proposed estimator and controller is evaluated via computer simulation using Matlab/Simulink.