Automobile anti lock braking system control based on a least squares support vector machine

Using the referenced slip rate and angle acceleration of the wheel as input vectors and the braking pressure as an output vector, an automobile anti lock braking system (ABS) controller based on a least squares support vector machine (LS SVM) was designed. Training the LS SVM controller using the supporting vector, the parameter of the controller was calculated. An anti lock braking system was designed that includes an input layer, a control layer, and an output layer. Using wheel speed as an input, the braking pressure of each wheel was calculated. The pulse width modulation (PWM) method was used to control the braking pressure, and thereby to bring ABS control. An automotive ABS test and control system was constructed. Road tests under different conditions were completed according to international standards. Test results show that an anti lock braking control method based on LS SVM has good braking stability and adaptability. It is an effective new ABS control method.     

Control strategy of regenerative braking for hybrid electric vehicle based on engine braking

Focusing on a continuously variable transmission(CVT) hybrid electric vehicle with integrate starter generator(ISG), modeling and simulating of engine braking was conducted. An optical control strategy of regenerative braking was put forward. When there is no regenerative braking, engine brake force can be used effectively by changing the CVT ratio to reduce the braking force requirements for wheel brakes based on the calculated results of engine braking. When there is regenerative braking, the braking priority sequence is generator braking, engine braking, and finally frictional braking. A forward simulation model for regenerative braking system of hybrid electric vehicle was built. The simulation and analysis under typical driving cycles was conducted. The result shows the control strategy and the models are reasonable and feasible.     

Simulation analysis on braking system of hybrid vehicle with ISG

A hydraulic braking system of the hybrid vehicle is designed based on braking force distribution and brake pressure coordination control strategy of integrated startor and generator(ISG) hybrid electric vehicle(HEV). Simulation model of hydraulic braking system has been established using AMESim software platform. Dynamic performance simulation and analysis to the key components and systems are performed. The results verify the correctness and feasibility of system program and provide evidence for designing and optimizing of HEV braking system.     

Hardware-in-loop Simulation on Regenerative Braking for Hybrid Electric Powertrain with ISG

Regenerative braking is one of main performance modes, which can reduce fuel consumption and emission. A dynamics braking control model is built for hybrid electric vehicle with ISG, an off-line simulation is completed. A regenerative braking rig in dSPACE environment is built on the hybrid electric powertrain. The tests and analyses for different speed, deceleration shift and clutch state is completed in a Hardware-In-Loop simulation, which lays a foundation for the optimization of regenerative braking control strategy for HEV.     

Study and Simulation on Control Strategy for CVT Ratio in HEV when Regenerative Braking

In order to satisfy the safety of vehicle braking and the fuel economy,a control strategy for regenerative braking force distribution is proposed by considering of battery SOC and braking severity.In addition,a CVT speed ratio control strategy is proposed to operate the motor in the high efficiency area to improve motor generating efficiency.A simulation model of mild hybrid electric vehicle is set up.Simulation result on ECE+EUDC typical driving cycles show that the effectively regenerating energy of braking of hybrid vehicle with CVT is lager than that of hybrid vehicle with MT by 2.5%.     

Test Bench of Air Braking System for Vehicles

The stability of the brake system is a key factor for the vehicle safety.It is important for the air braking system's stability to shorten the time lag between the front brake and the rear brake,the reasonable disposal of the air pipeline and the optimization of the braking system design.A test bench is developed to test the performance of the air braking system,which is mainly made of pressure sensors,signal amplifiers,data acquisition system,computer,pressing air resource and so on.Based on this test bench,the reaction time of the system while braking and abandoning brake can be measured.Using this test bench,the performances of the air braking system of a certain commercial vehicle is detected.Compared with the actual road test,it can save the cost and the time for experiment largely.     

Vehicle Lateral Stability Control Based on Sliding Model Control

In view of the vehicle cornering or path changing under ultimate handling maneuver, a 3-DOF nonlinear vehicle dynamics model which takes the vehicle lateral velocity, yaw rate and body roll angle as the State variables is presented. Based on the dynamic analysis, the method which using additional yaw moment produced by different longitudinal braking force among each wheels to improving vehicle handling stability in emergency situations is discussed. Considering the sideslip angle as one of the vehicle state variables is difficult to measuring, the sideslip angle estimation based on vehicle dynamic model and kinematics is designed. And then, based on the theory of siding model control, the combining sliding model control system is founded, which taking the vehicle yaw rate and body side-slip angle errors between the estimated and the real as the input variables, and taking the braking torque and the steering angle as control aims. The simulation results indicate that the control method can effectively improve the vehicle lateral handling stability.     

Vehicle stability control system design using optimal allocation of yaw moment

In order to improve vehicle handling stability,a control system using optimal allocation of yaw moment was designed.The first layer is a linear quadratic regulator (LQR) controller,which optimizes a desired yaw moment to work on the vehicle and calculates reference wheel slip for the target wheel.The second layer of the control system is a PID controller which can track the reference wheel slip rate,and then apply braking torque on the target wheel to make the vehicle stable.Simulations are carried out by using an 8-dof nonlinear vehicle model under different conditions.The simulation results indicate that the designed control system can effectively improve vehicle handling stability.     

Control Strategy and Simulation Study on NiMH Battery Quick Charging for Regenerative Braking of HEV

Based on the result of NiMH battery performance experiments, changing trend of maximal temperature and difference in temperature of HEV NiMH battery in different SOC and different charging current is analyzed. Considering the working situation of HEV NiMH battery and the theory of battery quick charging, a control strategy for NiMH battery quick charging is described which adapts to HEV regenerative braking system based on Mascc law. By Modeling and simulating the process of NiMH battery quick charging with this strategy, constant voltage charge method and constant current charge method, validates this control strategy.     

纯电动车车用复合储能装置控制策略及参数优化

为解决目前纯电动车动力电池比功率不足的缺陷,对纯电动车的储能装置进行了研究。根据复合储能装置的特点和目的,制定了复合储能装置的工作模式,提出了基于速度与电流约束的模糊控制策略。为了进一步提高整车性能并降低蓄电池的输出电流,对复合储能装置的关键参数进行了线性优化,仿真结果表明:加装复合储能装置的纯电动车的加速时间缩短了12%,制动能量回收效率提高了39%,百公里耗电量减少了8.55%,并显著降低了蓄电池的输出电流,有效延长了蓄电池使用寿命和整车的续驶里程。     

Design and Application of a New-style High Resolving Capability Scanning Tunneling Microscope

A new-style STM is presented. With its automatic advancing, braking and locking devices, it can achieve the tunneling state semi-automatically. Scanning programmed makes it work more quickly. A special software is used to manipulate the imagines. This gives us a better way to know the information of the surface of the specimen. By comparing typical images obtained with the acknowledged ones, its resolving capability given transverse is 0.1 nm, and vertical is 0.01 nm. Several images are given as samples.     

Modeling and Simulation of a Mini-bus With Dynamics of Multi-body Systems

A few of new structures, which represent technical characteristics of mini- bus design today, have been applied into development of a new type mini- bus. Modeling of the mini- bus with dynamics of multi- body systems was researched into by using the ADAMS software, and then validity of the vehicle model was verified. Furthermore the operational stability of the mini- bus was investigated and evaluated by simulation analyses such as step steer analyses, snake cornering analyses, braking analyses in line, as well as complicated course analyses and so on.     

Development and Design of ABS Dynamic Test-bed for Automobile

Aiming at the problems of ABS products tested on vehicle, a character test-bed of automobile and motorcycle ABS is studied.To provide an economic and efficient test method for vehicle anti-lock braking system(ABS) in laboratory,the idea of designing a dynamic test-bed is researched and developed,which can simulate actual working status of automobiles well and truly.The test-bed structure character,design principle and key techniques are discussed.It will provide a new method for testing ABS products of automobile and motorcycle.     

Modeling and simulating the vehicle riding dynamics considering gradient effects

Considering road characteristic parameters such as lateral gradient, longitudinal gradient and synthetic gradient, and based on 15 degrees of freedom (DOF) vehicle dynamics model, the authors develop the vehicle dynamics model, tire vertical load variation model and whole vehicle riding dynamics simulation model combined with steering system, braking system, power train system, wheel and suspension models. The situations are compared under different lateral, longitudinal, synthetic gradient and vehicle speed. The simulation results show that yaw rate maintains invariably to longitudinal gradient variation, but decreases gradually with the increase of lateral and synthetic gradient. The margin of fluctuation and peak value increase with the increase of vehicle speed under the same gradient; front wheel sideslip angle maintains invariably to longitudinal and synthetic gradient variation, yet increases with the increase of lateral gradient; the roll rate decreases and then increases with the increase of lateral and synthetic gradient, and the margin of fluctuation and peak value increase with the vehicle speed increase under the same longitudinal gradient.     

Parameter Simulation on the Control Strategy for a Parallel Hybrid Electric Vehicle by CRUISE

The purpose of a parallel hybrid electric vehicle(PHEV) is for the best energy distribution between internal-combustion engine(ICE) and electric motor though the appropriate control strategy.It can not only keep the advantage of the ultra-low emission of electric vehicles(EV),but also take advantages of the hyperbaric energy of ICE.Simulation model for PHEV is built based on CRUISE,an auxiliary control strategy is designed,and then parameter simulation study on the control strategy is performed.The simulation results show that according to the different control requirements,the vehicle performance can be improved by adjusting!the corresponding control parameters.     

Evidence for a ‘uniculm effect’ in spring wheat (Triticum aestivum L.) in a mediterranean environment

Summary The concept of the uniculm habit as an important feature of a wheat ideotype for a mediterranean environment was evaluated under field conditions. A uniculm plant produces a single shoot and when sown in a stand exemplifies a non-tillering crop with a fixed density of shoots throughout the growing season. Yield and harvest index of normal tillering spring wheat was compared with that of the same crop surgically detillered throughout the growing season to a constant density of 2 shoots per plant. The use of a biculm, whilst retaining the uniculm principle of a fixed density of shoots throughout the growing season, permitted comparison on a single crop sowing at normal field density.The control plots followed the usual pattern of tillering for the region attaining a maximum of about 4.0 shoots per plant by early spring. Shoot number declined to 2.3 and 2.6 per plant by maturity in 1978 and 1979, respectively.Detillered plots outyielded the controls by 14 per cent in 1978 (2.05 v. 1.80 tonnes ha^-1) and 22 per cent in 1979 (1.84 v. 1.51 tonnes ha^-1). Harvest indices were 0.39 v. 0.35 in 1978 and 0.30 v. 0.24 in 1979 for detillered and control plots, respectively.Higher leaf area indices and better water relations after anthesis in biculm stands indicated more efficient water use when shoot population was controlled at near optimum level. Irrigation at anthesis reduced the difference in yield between detillered and control plots.Although the uniculm principle was demonstrated with biculms in practice control of shoot number will require the use of genetic uniculms.     

Does pollarding trees improve the crop yield in a mature alley-cropping agroforestry system?

In agroforestry systems, the canopy of maturing trees progressively reduces the radiation available for the crop. Tree management practices such as pollarding can be used to restore the crop light availability. We monitored durum wheat, barley and pea yields during three consecutive years in an alley-cropping agroforestry system with hybrid walnut trees in Southern France. Trees have been pruned regularly to 4 m since planting (in 1995), and a section of 50 trees was pollarded at 4 m height for the first time in 2013. We measured the yields and yields components in the two different tree management systems and in a sole crop control. The non-pollarded trees reduced significantly the incident light (around 80% of the global radiation left in average) and both wheat (68% of the control) and pea (69% of the control), but not barley mean yields. In pollards inter-row, the average incident light was 98% of the total radiation the first year and the wheat yield 89% of the control. But 3 years after pollarding, the incident light was 79% of the total radiation and the pea yield was only 67% of the control. Pollarding had a transient positive impact on crop yield; after 3 years, pollards were more competitive for light than control trees. Pollarding may also reduce the belowground trees competition, but slightly, as the crop vegetative growth occurs when the trees are leafless.     

Research and development of a testing control system for a heavy duty vehicle automatic mechanical transmission test bench

Automatic mechanical transmissions (AMT) are suitable for use in heavy duty vehicles. Bench testing is an important task of the research and development. Many objectives, such as AMT performance testing, matching AMTs with engines, and optimizing control rules, can be achieved through bench testing, thereby laying a foundation for AMT application. An AMT testing bench is built up based on a developed AMT. By analyzing the performance requirements of AMT bench testing for heavy duty vehicles, a testing controlling system scheme is proposed and methods of data acquisition and communication are analyzed. Control methods for actuators are proposed based on analyzing the characteristics of AMT actuators. A testing control program for AMT bench testing is developed based on the Delphi platform. The entire bench testing system possesses advances test functions.     

Annual Medicago as a Smother Crop in Soybean

Use of conservation tillage and narrow row spacing in soybean [Glycine max (L.) Merr.] production has led to increased use of herbicides for weed control. Some producers are seeking alternative weed control methods, such as smother crops, that would reduce dependence on chemical weed control. A successful smother crop must compete strongly with weeds but minimally with the crop. In four environments, we intercropped three annual Medicago spp. (medics) with soybean to test their utility as a smother crop for weed control. Annual medics were intercropped with soybean at rates of 0, 85, 258, or 775 seeds m^?2, and the intercrops were grown with and without weed control. Increasing medic seeding rate decreased weed yields but also reduced soybean herbage and grain yields. For the weed‐controlled treatment, average soybean grain yields declined 7 kg ha^?1 for every 10 seeds m^?2 increase in medic seeding rate. Soybean grain yield was lower when grown with Medicago scutellata L. cv. Sava than when grown with Medicago polymorpha L. cv. Santiago or Medicago lupilina L. cv. George. Soybean grain yield was negatively related (r=?81) to medic herbage production. In the autumn following soybean harvest, medic residue ranged from 200 to 3700 kg ha^?1 depending on the location and seeding rate. Medics provided residue for soil protection, suppressed weeds, but also reduced soybean yields.     

A Study on Human Simulation Intelligent Control Algorithm to a Category of Objects

Based on the model of Human Simulation Intelligent Controller (HSIC) presented briefly, a detailed algorithm was described for the servo system control by using the method of HSIC. Simulation results obtained proves the good performance of the control algorithm.