Dynamic Control Function Research Articles

Estimation of the inertial parameters of vehicles with electric propulsion

More accurate information about the basic vehicle parameters can improve the dynamic control functions of a vehicle. Methods for online estimation of the mass, the rolling resistance, the aerodynamic drag coefficient, the yaw inertia and the longitudinal position of the centre of gravity of an electric hybrid vehicle is therefore proposed. The estimators use the standard vehicle sensor set and the estimate of the electric motor torque. No additional sensors are hence required and no assumptions are made regarding the tyre or the vehicle characteristics. Consequently, all information about the vehicle is available to the estimator. The estimators are evaluated using both simulations and experiments. Estimations of the mass, the rolling resistance and the aerodynamic drag coefficient are based on a recursive least-squares method with multiple forgetting factors. The mass estimate converged to within 3% of the measured vehicle mass for the test cases with sufficient excitation that were evaluated. Two methods to estimate the longitudinal position of the centre of gravity and the yaw inertia are also proposed. The first method is based on the equations of motion and was found to be sensitive to the measurement and parameter errors. The second method is based on the estimated mass and seat-belt indicators. This estimator is more robust and reduces the estimation error in comparison with that obtained by assuming static parameters. The results show that the proposed method improves the estimations of the inertial parameters. Hence, it enables online non-linear tyre force estimators and tyre-model-based tyre–road friction estimators to be used in production vehicles.

A convection-driven long-range linear gradient generator with dynamic control.

We developed a novel gradient generator to achieve long range and linear chemical gradients with a dynamic control function. The length of the gradient can be on the centimetre scale. The gradient profile can be tuned by changing the flow rates. The device can work in both high flow rate regimes with large shear stress and low flow rate regimes with minimum shear stress. The drug screening function was demonstrated by the viability test of PC-9 cancer cells.

Research on the Mechanism of Combined Raceway Superfinishing Technique of Precision Bearing

This paper analyzes the mechanism of combined raceway superfinishing technique of precision bearing, via the relationship between coarse and superfinishing oilstone and raceway geometric accuracy, probes forming mechanism of raceway geometric accuracy under double oilstone pressure as well as auto dynamic control functions. Additionally, this paper analyzes the feasibility of combined coarse and superfinishing technique, brings forward practice methods and steps of combined finishing technique; discusses how to realize smooth transition of technique parameters, so as to reduce surface texture changes of working pieces, achieve assistant grinding of superfinishing oilstone, improve surface quality of raceway and decrease reflection error of superfinishing. Meanwhile, this paper adopts embeded technology to realize auto dynamic control of oilstone pressure, so as to effectively eliminate surface error resulted from oilstone raising and furthermore enhance surface geometric accuracy of precision bearing.

Development of practical shape models and control system for strips

High-quality-oriented in the steel market encourages more severe tolerances of strip crown and flatness. GSM (Global Shape Model) provides the superior setup calculation with learning calculation and dynamic control functions in order to achieve targets of both crown and flatness. Adopted Models are simplified but contrived enough to cope with physical phenomena such as roll stack deflection, longitudinal and lateral flow of rolled strip and inter-stand relaxation. Systematic structure of GSM enables itself to be applied to actual hot strip mills with related functions as like roll profile prediction. The results of the application of GSM to a Hot Strip Mill are also shown in this paper.

Formulations about Dynamics of Mobile Robots

In this paper the dynamics equations for a mobile robot, named PatrolBot, will be developed, using new concepts in advanced mechanics, based on important scientific researches of the main author, concerning the kinetic energy. In keeping the fact that the mathematical models of the mobile platforms are different besides the other robots types, due to nonholonomic constraints, these dynamic control functions, will be computed, according to these restrictions for robot motion.

Coiling Temperature Control Using Temperature Measurement Method for the Hot Rolled Strip in the Water Cooling Banks

In the hot strip mill, the quality of the strip greatly depends on the cooling process between the last stand in the finishing mill and the coilers. Therefore, it is important to carefully control the coiling temperature to regulate the mechanical properties of the strip. To realize high accuracy of coiling temperature, a new coiling temperature control using temperature measurement method for the hot rolled strip in the water cooling banks has been developed. The features of the new coiling temperature control are as follows: (i) New feedforward control adjusts ON/OFF swiching of cooling headers according to the strip temperature measured in the water cooling banks. (ii) New feedforward control is achieved by dynamic control function. This coiling temperature control has been in operation successfully since 2008 at Kashima Steel Works and improved the accuracy of coiling temperature of high strength steel considerably.

Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic fluid

Magnetic fluid is first introduced into the traditional cantilever-beam senor. Based on the property of the cantilever-beam and the novel controllable magviscosity of magnetic fluid, the output of cantilever-beam sensors is under control so that the controllable output of the sensors can be realized. The mathematical model of the sensors is established and analyzed. The dynamic control function and the following educational results, which include the two curves of the displacement ratio and phase function with the different damping ratio and frequency ratio, are obtained based on the model. The result shows that it is valid to realize the controllable output of the sensors by controlling the viscosity of the magnetic fluid, and finally the expanded measurement range can be realized.

Intelligent Genetic Algorithm and Its Application to Aerodynamic Optimization of Airplanes

A new genetic algorithm (GA), called intelligent GA, is proposed by the inclusion of a fractional factorial design in the crossover operator to determine the best combination of design variables. That is, in the proposed GA, the chromosomes of children are generated via an intelligent crossover process with factorial experiments after completing the selection of GA operators. This gene mating process differs from the traditional GA, where the child chromosome is generally generated via randomization. Accordingly, the traditional GA incorporating the technique of fractional factorial design into the crossover operator markedly enhances the performance in terms of evolutionary efficiency. Another GA, called Taguchi-GA, that incorporates the Taguchi orthogonal arrays into the crossover operator is also developed to compare the performance of the presented intelligent GA. Four representative test cases, including two multimodal functions, a nonlinear dynamic control function, and a profile fitting of a high lift airfoil are performed via the traditional GA, micro-GA, Taguchi-GA, and present GA to assess the capacity and efficiency of the proposed GA. The computational solutions of the convergence history and optimal objective function for the test cases demonstrate that the proposed intelligent GA outperforms the other three GAs. Moreover, the presented new intelligent GA and the other three GAs are applied to the aerodynamic optimization of two airplanes, namely, an advanced defense airplane and an F-16A fighter. The redesigned wing planform is obtained by computations made with an aerodynamic flow solver, and the present GA depicts the optimal swept angle, aspect ratio, and taper ratio. The drag distribution and convergence history show that the proposed intelligent GA has a high evolutionary efficiency when applied to practical engineering problems.

Observation of the Velocity of Body Sway Ménière's Disease

Vestibulo-spinal reflexes in Ménière's disease were analyzed using gravigrams and velocitygrams.Studies of vestibular disturbance have so far been centered around nystagmus. With the development of the gravicorder, however, a new approach to the testing of vestibulospinal reflexes began to be tried, which is based on the analysis of the center of gravity.A characteristic of gravigrams is that they are positional graphs and provide no information about time-course changes in the velocity with which the center of gravity moves. To clarify time-course changes in the velocity of the sway of the center of gravity while recording its movement, we processed data of the change in the time-course velocity, a component of dynamic control system, with a computer and obtained velocity-grams.On gravigrams, body movements differing in frequency are represented by the same area change as long as their amplitudes are the same. These same body movements, however, produce completely different velocitygrams, which are constructed on the basis of differentials of the above recordings.Eleven patients with Ménière's disease were then tested during a non-attack period with their eyes open and closed. It became clear from the above test that, even among patients who exhibited the same pattern of area change on gravigrams, velocitygrams were different from each other. This means that the velocity is controlled by a different recovery conditions.That the velocitygrams of patients in a non-attack period varied greatly suggests that each patient responded differently to treatment.The above findings indicate that the velocity of body sway, which is a parameter of the dynamic control functions, plays an important role in the clinical diagnosis of equilibrium disturbance.