81 results about "Kinetic theory" patented technology

The invention relates to a road gradient and car state parameter combined estimation method based on a parameter estimation error, and belongs to the field of vehicle engineering. The method comprises the steps of firstly establishing a car driving longitudinal kinetic model according to a car kinetics theory and the newton second law; measuring a car speed and a driving force of an engine by virtue of a car-borne sensor, and adopting the measured car speed and the driving force as input quantities of an estimation algorithm; filtering the car driving longitudinal kinetic model, and extracting a parameter estimation error; judging whether an excitation condition is satisfied: estimating an unknown parameter vector by utilizing a vector designing self-adaptive law containing the parameter estimation error if the excitation condition is satisfied; adding random interference to the driving force if the excitation condition is not satisfied, and returning for re-measurement; finally calculating estimated values of a road gradient, car weight, viscous friction coefficient, rolling friction coefficient and air resistance coefficient by virtue of basic mathematical manipulation. By adopting the method, the cost is reduced, the accumulation of measurement noise can be avoided, and the precision is improved; the calculation quantity is reduced.

An UAV dynamic path planning method suitable for high-speed environment combines the theory of kinematic mechanics, establishes speed-dependent gravitational and repulsive functions, increases the virtual resistance, abandons the concept of "potential field", and directly calculates the resultant force born by the UAV through the virtual force function. The simulation experiments show that the method is effective and safe when the UAV is moving at high speed. The beneficial effect is that the method of the invention does not need to generate the motion path of the UAV, and only needs to calculate the expected resultant force of the UAV, not only reduces the complexity of the algorithm, but also substitutes the desired acceleration for the desired position as the input of the control system, so that one closed loop is omitted, the system complexity is lowered, the stabilizing time is greatly shortened, and the problem that the existing path planning method is not suitable for the high speed environment.

The invention discloses a method for predicting a pyrolysis process of environment-friendly flame-retarding asphalt, belongs to the technical field of flame retarding of asphalt pavements, and solves the problems of low prediction accuracy in the pyrolysis process of an asphalt material and lack of scientific theoretical basis in the prior art. By virtue of the method, the pyrolysis behavior of the environment-friendly flame-retarding asphalt in a high-temperature environment can be deeply revealed. The method comprises the following steps: adding an environment-friendly flame retardant magnesium hydroxide in hot asphalt according to a certain proportion; fully stirring to prepare a uniform and stable flame-retarding asphalt sample; performing test through a thermogravimetric analyzer to acquire data such as a thermogravimetry-derivative thermogravimetry (TG-DTG) curve and char yield; performing optimization and identification through a reaction mechanism according to a thermal analysis kinetic theory, determining a flame-retarding asphalt pyrolysis reaction mechanism function and a conversion rate function to work out pyrolysis kinetic parameters of a flame-retarding asphalt material, namely activation energy and pre-exponential factors; establishing a flame-retarding asphalt pyrolysis model with certain flame retardant mixing amount to obtain a flame-retarding asphalt pyrolysis TG curve through the model so as to predict an asphalt pyrolysis process.

The invention provides a method for designing a passive vibration isolation system for a flywheel of a satellite. The method includes analyzing configuration and composition of the flywheel, creating and correcting a multi-body kinetic model of the flywheel on the basis of a multi-body kinetic theory and a finite element theory; providing a design of a passive vibration isolation scheme for the flywheel according to ground test data and a simulation analysis result for vibration characteristics of the corrected model of the flywheel; performing simulation analysis on the performance of the scheme according to a combination of the design of the scheme and the kinetic model of the flywheel, verifying the scheme by means of ground tests if index requirements are met, or redesigning the scheme if the index requirements are not met; performing ground passive vibration isolation tests on the flywheel in order to further verify the feasibility of the scheme, completing a design procedure if requirements are met, or redesigning the passive vibration isolation scheme if the requirements are not met. The passive vibration isolation scheme includes a vibration isolator rigidity design, a damping design and a layout design. The method has the advantages that micro-vibration interference of the flywheel on a satellite platform can be effectively reduced, and technical support can be provided for development of high-precision, high-resolution and high-stability hyper-static platforms.

The invention belongs to the field of road traffic safety. In order to provide a method for traffic safety evaluation during phase switching and achieve the purpose, the invention adopts the technical scheme that the method for evaluating traffic safety of signal intersection during phase switching facing an operation management stage comprises the following steps of: calculating encountering time difference PET, wherein PET=(Y+AR+te)-tc-Te; calculating collision loss of momentum, assuming that two cars collide with each other by keeping the original speed, according to the collision kinetic theory, calculating the loss of momentum before and after collision according to formula 5, wherein the system collision before momentum Pm; calculating the collision occurrence probability P; and carrying out evaluation on the traffic safety of the intersection during phase switching. The method is mainly applied to the design of roads meeting the requirement of traffic safety.

The invention discloses a wind turbine generator system self-adaptive inversion sliding mode optimized control method based on a high-order sliding mode observer. The method includes the steps that a,a mathematical model of a wind turbine generator system is established according to kinematics and dynamics theories; b, a self-adaptive inversion sliding mode controller of the wind turbine generator system is designed on the basis of the traditional optimal torque method design through inversion control, self-adaptive control, sliding mode control theories and the mathematical model; c, the system state is estimated online in real time through the high-order sliding mode observer, the power output is smoothened, and shake and vibration are reduced; d, parameter optimization is conducted onthe designed controller through a particle swarm algorithm to find the optimal control parameter; and e, self-adaptive inversion sliding mode control is conducted on the wind turbine generator systemthrough the self-adaptive inversion sliding mode controller with the control law. In this way, the problems that the wind turbine generator system has unknown parameters and bonded disturbance are solved, and robustness of the system is improved. Finally, the maximum power point tracing control of the wind turbine generator system in the low-wind-speed area is achieved.

The invention relates to non-optical spherical elements, in particular to a splicing measurement method for two sections of profiles of a large-caliber optical aspheric element. The splicing measurement method includes providing a method of aligning data points of an overlapped area on the basis of a principle that radius of curvature is unchanged; building a preliminary optimized mathematic model for twp-section surface figure profile splicing according to a multibody system kinetic theory, a slope difference value and an inversion method; according to a simulation result of the preliminary splicing mathematic model, performing linear least square fitting on preliminary splicing errors, removing accumulated errors, and providing a final two-section splicing optimized algorithm. Experiments in which a Taylor Hobson contourgraph and an auxiliary measuring clamp are utilized to measure planar optical elements of 150mm and data processing by using the splicing optimized algorithm are performed, and results of the experiments show that maximum standard deviation of the splicing errors is 0.868 micrometer, and high-accuracy surface figure detection needs of optical elements at a grinding stage can be met.

The invention discloses automobile rollover evaluation indexes and evaluation method, and belongs to the field of vehicle active safety. In the method, the theory of vehicle rollover dynamics is applied to solve rollover threshold conditions of the automobile rollover evaluation indexes, and the rollover threshold conditions are converted into a phase diagram mode; and a roll angle, a roll angle acceleration and a lateral acceleration which are measured in real time during a driving process of the automobile are converted into a phase diagram of the roll angle and the roll angle acceleration,a phase diagram of the roll angle and the lateral acceleration and a phase diagram of the lateral acceleration and the roll angle acceleration, and the phase diagrams are compared with the rollover threshold conditions to judge whether the automobile is at risk of rollover. Driving parameters measured in real time are directly compared with the threshold conditions, and so the rollover evaluationindexes are accurate and the real-time performance is good. Furthermore, The imaging of the parameters can more directly reflect the influence of a plurality of parameters on the automobile rollover,which is conducive to guiding drivers or active safety equipment to take anti-rollover measures in actual driving.

A method for determining optimum catalyst particle size for a gas-solid, liquid-solid, or gas-liquid-solid fluidized bed reactor such as a slurry bubble column reactor (SBCR) for converting synthesis gas into liquid fuels considers the complete granular temperature balance based on the kinetic theory of granular flow, the effect of a volumetric mass transfer coefficient between the liquid and the gas, and the water gas shift reaction. The granular temperature of the catalyst particles representing the kinetic energy of the catalyst particles is measured and the volumetric mass transfer coefficient between the gas and liquid phases is calculated using the granular temperature. Catalyst particle size is varied from 20 μm to 120 μm and a maximum mass transfer coefficient corresponding to optimum liquid hydrocarbon fuel production is determined. Optimum catalyst particle size for maximum methanol production in a SBCR was determined to be in the range of 60-70 μm.

The invention provides a method for computational fluid dynamics and apparatuses making enable an efficient implementation and use of an enhanced jet-effect, either the Coanda-jet-effect, the hydrophobic jet-effect, or the waving-jet-effect, triggered by specifically shaped corpuses and tunnels. The method is based on the approaches of the kinetic theory of matter providing generalized equations of fluid motion and is generalized and translated into terms of electromagnetism. The method is applicable for slow-flowing as well as fast-flowing real compressible-extendable generalized fluids and enables optimal design of convergent-divergent nozzles, providing for the most efficient jet-thrust. The method can be applied to airfoil shape optimization for bodies flying separately and in a multi-stage cascaded sequence. The method enables apparatuses for electricity harvesting from the fluid heat-energy, providing a positive net-efficiency. The method enables generators for practical-expedient power harvesting using constructive interference of waves due to the waving jet-effect.

The invention discloses a method for separating and extracting shell pieces and clitellum from kieselguhr or diatoms. The method comprises the following steps of: classifying and extracting the shell pieces and the clitellum by adopting a Stokes sedimentation method in the extraction process; calculating the sedimentation velocity difference between the shell pieces and the clitellum with same particle diameters by combining with a fluid dynamics theory; and carrying out sedimentation by adding deionized water a plurality of times to finish high-purity classification and extraction of the shell pieces and the clitellum. The method can not damage structures of the shell pieces and the clitellum and keep the topography and the microstructure of the original species of diatoms, and the shell pieces and the clitellum are only separated at connecting strips. 0.2 to 0.6g of shell pieces and 0.1 to 0.3g of clitellum can be extracted from 1g of siliceous shells.

The invention relates to the technical field of freshness preservation, in particular to a fruit and vegetable respiration rate model. A fruit and vegetable respiration rate modeling method comprises the following steps of: firstly, establishing a model that a respiration rate changes along with storage time: r=K1{1-K2exp(-kdt)}, in the formula, K1=ks/kd*k and K2=1-kd/ks[E]0; secondly, on the basis of the established model that the respiration rate changes along with storage time, establishing a respiration rate model which contains a storage temperature and a storage time factor: r=K3{1-K2exp(-kdt)}, in the formula, K3=ks/kd*Aexp(-Ea/RT); and finally, on the basis of the established respiration rate model which contains the storage temperature and the storage time factor, establishing the respiration rate model which contains a gas volume fraction and the storage time factor: r=K4{1-K2exp(-kdt)}, in the formula, K4=ksktheta/kd*ayO/(1+ayO+aiyOyC). Due to the adoption of the technical scheme, a mathematical model about the respiration rate of fruit and vegetable main bodies is established based on an enzyme kinetic theory to lay a theoretical foundation for the predication of the respiration rate of the fruit and vegetable main bodies in an air conditioned storage period and the analysis of storage quality.