In this study, a fuzzy gain scheduling controller is proposed to parallel park the car-like robot. At first, a fuzzy sliding mode controller (FSMC) embedded by driving experience is developed to locally track a most t...
详细信息
In this study, a fuzzy gain scheduling controller is proposed to parallel park the car-like robot. At first, a fuzzy sliding mode controller (FSMC) embedded by driving experience is developed to locally track a most typical path for the parallel parking. In order to extend the controlled region, several typical paths are formed and can be pieced together to constitute a complete parking path in a large region. Then, a fuzzy gain scheduler with knowledge-based structure is proposed to decide the best parking path and to generate the proper control gains.
In this paper, passive walking of the eight-legged robot Quartet that has simple straight legs, and is also constrained to have two degrees of freedom for the simplicity of its motion, is described. It is known that a...
详细信息
In this paper, passive walking of the eight-legged robot Quartet that has simple straight legs, and is also constrained to have two degrees of freedom for the simplicity of its motion, is described. It is known that a legged robot can continue to walk down a slight slope steadily without any actuation if appropriate initial conditions are given. Since no control input except for gravitational torque is applied to the robot, more natural gaits compared with those of conventional actuated walking robots are expected. In walking simulation, bifurcation that occurs along with the increase of slope angle and finally leads to chaotic gait is discussed. In walking experiment, some kind of trajectory stability can be observed.
controller synthesis for protecting the vehicle from spin is described as a robust stabilization problem against perturbations of rear cornering force. The controller is designed by gain-scheduled H∞ control theory s...
详细信息
controller synthesis for protecting the vehicle from spin is described as a robust stabilization problem against perturbations of rear cornering force. The controller is designed by gain-scheduled H∞ control theory so that the closed-loop system satisfies an H∞ norm condition guaranteeing the stability of the vehicle. The controller adjusts the braking force distribution to the right and the left wheels. The result has been tested by executing experiment. The experimental results showed that the designed controller can robustly stabilizes the vehicle and protects it from spin under the presence of large perturbations of rear cornering force.
By adding an electronic throttle and a torque sensor to an engine equipped with variable cam timing, it is potentially possible to vary cam phasing to improve emissions and fuel economy while preserving the torque res...
详细信息
By adding an electronic throttle and a torque sensor to an engine equipped with variable cam timing, it is potentially possible to vary cam phasing to improve emissions and fuel economy while preserving the torque response of a conventional non-VCT engine. To do so effectively, however, requires the use of multivariable control. A controller consisting of decentralized individual control loops will not yield satisfactory performance because such a controller cannot compensate for system interactions. Yet, a fully multivariable controller may not prove necessary in order to achieve the desired performance. In this paper, we design linear multivariable controllers at a number of operating points and simplify the resulting controllers by eliminating cross-coupling terms that do not affect the closed loop response. Doing so provides insight useful in tuning controller parameters.
Zoning is one conventional way to make an existing elevator system adapt to different traffic patterns. However, zoning is generally either fixed permanently or static based on time scheduling where the floors being g...
详细信息
Zoning is one conventional way to make an existing elevator system adapt to different traffic patterns. However, zoning is generally either fixed permanently or static based on time scheduling where the floors being grouped into zones are predetermined during the design stage. In this paper, a new concept is introduced that can provide the feature of dynamic zoning for a elevator system based on the real time traffic patterns. The objectives are to achieve maximum handling capacity of the system and minimum waiting/travelling time for passengers during up-peak and down-peak traffic conditions. Two new algorithms, namely `Uniform RTT' and `Demand Matching', have been developed for intelligent control. Information related to real time zoning can be delivered to passengers by LED display boards installed at each landing above the landing doors. A computer simulation based on a software package on market, Elevator 2.0, has revealed that the two new algorithms can improve the passenger waiting/travelling time under the two major traffic conditions. The original concept of dynamic zoning was published in an elevator journal.
The Furuta pendulum is used to evaluate a friction compensator based on the dynamic LuGre friction model. The effect of friction compensation is very well illustrated by reduction of limit cycles when stabilizing the ...
详细信息
The Furuta pendulum is used to evaluate a friction compensator based on the dynamic LuGre friction model. The effect of friction compensation is very well illustrated by reduction of limit cycles when stabilizing the pendulum. The observer based LuGre friction compensator is compared with classical Coulomb and Stiction compensator schemes. Existing analysis of the LuGre observer is extended to observer based friction compensation in general linear state feedback control of linear time invariant systems where friction enters the system at the input. In particular this observer based friction compensation is applicable on the pendulum. The performance of the LuGre compensator was found to be similar to that of the Stiction compensator. Important differences is the smooth control signal obtained from the LuGre observer, and that it uses less prior information.
The precision and micro assembly requires special tools in order to fulfill the high demands in accuracy and control of the assembly process. Our new precise gripper tool with 2dof, the micro positioning system (MPS),...
详细信息
The precision and micro assembly requires special tools in order to fulfill the high demands in accuracy and control of the assembly process. Our new precise gripper tool with 2dof, the micro positioning system (MPS), enables micro assembly with standard industrial robots by compensating for vibrations and inaccuracies of the handling device. The new developed controlsystem combines data of three diverse sensors to perform the corrective movement. The designed controlsystem of the MPS consists of two closed-loop and one open-loop regulator. A classical controldesign with pole-zero cancellation is used to linearize the hysteresis of the piezo actuator. An H2-regulator using only acceleration feedback is the main part of the controlsystem and generates a control signal proportional to the position for the actuator's corrective movement. The third regulator handles the reference input. The realized controlsystem reduces vibrations to less than 30%, the position accuracy without disturbances is better than 2 microns according to experimental results.
A novel capturing method of tumbling objects in non-gravitational field is proposed, aiming for the future on-orbit service missions such as capturing failed satellites or manned vehicle which loses control, or removi...
详细信息
A novel capturing method of tumbling objects in non-gravitational field is proposed, aiming for the future on-orbit service missions such as capturing failed satellites or manned vehicle which loses control, or removing debris. The key technology for this capture is how to compensate for the difference of rotational motions between the chaser and the target at the moment of capture. Most conventional methods use manipulator movement for this objective while keeping the position and attitude of the chaser body constant, which limits the allowable rotational velocity and patterns of the tumbling motion of the target. In the proposed method, the chaser aligns its rotational motion with the target's one by appropriate control before capturing the target, which is expected to enlarge the allowable target rotational motion range. Technical issues to realize it are discussed and our approach to them are proposed, which is verified with some computer simulations and hardware experiments.
The models that describe the dynamics of reaction systems are usually complex and uncertain. To simplify their description it is useful to identify the states which are dependent/independent of the reactions and flows...
详细信息
The models that describe the dynamics of reaction systems are usually complex and uncertain. To simplify their description it is useful to identify the states which are dependent/independent of the reactions and flows. This allows us, for instance, to design observers which are independent of the (highly uncertain) reaction functions and, in principle, simplify the controller design. The main contribution of this paper is to show the utility of nonlinear state-dependent time-scaling to carry out these objectives. First, we prove the existence of attractive invariant manifolds, which allows us to reduce the dimension of the system under study. Second, we design reaction-independent observers, which are simpler than the existing ones, and have a guaranteed convergence rate in all operating regimes. As an application we study a fifth order baker's yeast fed-batch fermentation process model, for which we reduce the essential dynamics to the plane. A simple input-output feedback linearizing controller is designed and its asymptotic stability established.
The major objectives of this paper are to analyze and model, control and optimize advanced diesels with optimal electronic fuel systems in order to improve fuel economy and reduce emission, guarantee the desired perfo...
详细信息
The major objectives of this paper are to analyze and model, control and optimize advanced diesels with optimal electronic fuel systems in order to improve fuel economy and reduce emission, guarantee the desired performance and increase service life, etc. Using a nonlinear mathematical model developed, a spectrum of problems in nonlinear analysis, control, and optimization are solved. In particular, using a complete mathematical model, the torque production features are studied. To inject the fuel into the cylinders, advanced fuel systems should be used to guarantee a spectrum of requirements to optimize the diesel performance. Thorough analytical results are performed, and novel control algorithms are designed and tested.
暂无评论