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Due to low-cost and simplicity, differential drive mobile robot are very popular in academic and hobby environments. However, in some applications, such as robot soccer, these robots need to move quickly and aggressively, thus requiring the use of techniques from control systems theory, where an accurate mathematical model is paramount. On the other hand, given budget limitations, the components used...
Control moment gyro (CMG) that driven by traveling wave traveling wave hollow ultrasonic motor have the closed loop stability control and multi objective angle fixed angle locking precision in large speed range demand. In this paper, a mathematical model of the control moment gyro system driven by traveling wave type hollow ultrasonic motor is established. Then taking into account the nonlinear characteristics...
This paper proposes an online compensation method of gravity and friction by least squares method (LSM) for robots implementing haptics. In order to expand the range of tasks using the robot such as telepresence robot, implementing haptics technology is essential. However, with higher gear ratio motors, the friction lowers the quality of the haptic transmission. In order to comfortably control the...
This paper talks about the creation of fast and lightweight 2D electric road vehicle models in order to design the whole electric powertrain. Two models are developed. The first one is very essential: it consists of three dynamics, that is full vehicle dynamics, front wheels dynamics and rear wheels dynamics; basic friction model is used. The second model is more complex: it also takes into account...
Welding is an important operation in manufacturing processes and it can represent a highly relevant amount of production costs, depending on material workpieces and required weld quantity. In mechanised and robotised welding processes, robot's travel velocity is an important parameter, which requires a proper regulation to obtain a good quality for weld beam. Then, in this work, a nonlinear model...
According to the characteristics of ship propulsion, the external load characteristics of the direct drive motor are analyzed. The overall design of the propulsion motor is taken as the starting point, and the optimal design of the electromagnetic loss is deduced. From the point of iron loss, copper loss and harmonic loss, to reduce the mechanical loss of the motor; From the point of bearing friction...
This paper mainly studies the angle tracking problem in electronic throttle system with unknown time-varying disturbances. Firstly, generalized proportional integral observer (GPIO) is used to estimate the time-varying disturbances including model uncertainties, friction torque and spring initial torque. Secondly, a composite controller combining disturbance estimation and backstepping control method...
Acquisition of practical skill in control systems development for nonlinear dynamic objects provides an opportunity to significantly improve training level of specialists in the field of controlling in technical systems. In this paper model of laboratory rig for development, investigating and debugging of position-control system of spherical object on a plane is presented. Mathematical representation...
The servo motion system plays an important role in the position accuracy of the Cartesian picking robot. During the automatic picking process, the nonlinearity of friction will affect position tracking accuracy. In order to improve the position accuracy of Cartesian robot, a mechanical model considering friction is established. Furthermore, fuzzy logic controller based on PID is used to control the...
Nowadays, the increase of mobility necessity combined with the targets to reduce pollution (emissions, noise, etc.) and the dependence to fossil fuels, strongly supports the development of electrics (EVs) and hybrid vehicles (HEVs). In this context, the present paper presents the main particularities of the traction systems of these vehicles, making a comparison with the classical internal combustion...
This paper intends to lay the groundwork for detection of backlash nonlinearity in a two-mass rotational system representing a vehicle driveline. It involves experiments and practical considerations prior to carrying out a system identification of the plant. Four possible system configurations are elaborated. Parameter estimation is then carried out in Dymola. Practical factors that affect the quality...
In this paper, the tracking control for a mechanical system with friction and backlash is considered. Friction and backlash nonlinearities often act on the main obstacles for high precision control. Based on the LuGre friction model and the Backlash model, a robust adaptive control algorithm is developed to compensate for friction and backlash nonlinearities by using backstepping design techniques...
Wheel hub drives provide the opportunity to control the torque at every wheel independently. Thus, safety functions like anti-lock braking system (ABS) or electronic stability control (ESC) can be implemented in the drives as well. This enables the substitution of friction brakes at the driven wheels by electric drives. In this paper, resulting requirements for the drive system are presented and an...
Many high-end power machines demand greater bearing performance in terms of running speed, precision, reliability, longevity, noise reduction, etc. An ultrasonic bearing based on Near-Field Acoustic Levitation (NFAL) effect is a kind of emerging noncontact gas bearing. Due to its self-aligning capability, the ultrasonic bearing can steadily run at a high speed under high precision. Actuated by piezoelectric...
Many high-end power machines demand greater bearing performance in terms of running speed, precision, reliability, longevity, noise reduction, etc. An ultrasonic bearing based on Near-Field Acoustic Levitation (NFAL) effect is a kind of emerging noncontact gas bearing. Due to its self-aligning capability, the ultrasonic bearing can steadily run at a high speed — tens of thousands of revolutions per...
This paper addresses a novel slip-ratio-based torque distribution strategy for electric vehicles (EVs) to avoid slippage when driving over a split friction surface. With the combination to an upper and middle controller, the desired driving force and yaw moment can be distributed to four driving wheels by utilizing the proposed lower controller. Stability analysis by using Lyapunov theorem is presented...
We perform a comparative analysis of energy-based performance criteria for the dynamics-based optimization of robot trajectories. The performance criteria considered include minimum torque, electrical power loss, approximation to mechanical work, and energy loss due to friction. Our dynamics model takes into account rotor inertias and gearing, and also considers robots subject to a range of motion...
The optimal control strategy for a wave energy converter (WEC) with constraints on the control torque is investigated. The goal is to optimize the total energy delivered to the electricity grid. Using Pontryagin's maximum principle, the solution is found to be singular-bang. Using higher order conditions, the optimal control on the singular arc is found as a function of the state and costate trajectories...
Ballscrew drive system has high mechanical efficiency and is able to get high gear ratio easily. But it also has non liner friction elements like rolling friction and viscous friction, so it makes ballscrew control accuracy worse. For that reason, it is proposed that inserting disturbance observer into control system and compensating disturbance torque. Generally, rotary encoder is used for position...
For flight attitude control problem affected by nonlinear property of hypersonic vehicle, the influences of nonlinear factors which are driving space, stiffness, friction torque in the electric servo mechanism are analyzed in this paper, and the definition and generation conditions of limit cycle caused by the backlash are also discussed. For the problems of limit cycle oscillation and the airfoil...
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