Research And Development Of Diesel Engine ASD Control Technology

With the increasingly stringent emission regulations and continuous improvement in consumer demand for driving comfort,integration of energy saving and emission reduction and the integration of control have become a general trend.Although the traditional diesel engine speed regulator which has developed for four generations still has the disadvantages of low control precision,large overshoot,and poor adaptation,it cannot meet current needs.Therefore,under this background,it is of great significance to develop a diesel engine speed regulator based on a torque structure.Therefore,a new control strategy has been developed and an ASD speed controller has been designed.Based on the diesel engine torque structure,the analysis and calculation of the ASD related torque modules is focused on and modeled by using Matlab/Simulink software.The main calculation and analysis modules are: demand torque,Overrun,limit torque,friction torque,transmission ratio,transmission coordination,and analyzing engine status.According to the control concept of guiding and setting the path,the ASD is designed to correspond to the two parts of the reference value ASDrf and the master control value ASDdc,both of which are subtracted to achieve the purpose of speed adjustment.ASDrf mainly realizes the recognition of the current working condition of the engine through the engine condition conversion and logic operation.Through the mapping function,the parameter group T1 and Kd are used to select the required torque filter,and the parameter groups A and B are used to limit the torque calculation.The controller uses the optimized PDT1 equation to implement the filter control.In order to deal with the fault conflict and loop count,an initialization module is designed.The ASDdc is mainly used to provide the compensation torque by pre-settling the speed change,and then to convert the fuel into the oil quantity,and adjust the speed.The control module adopts the D2T2 series method to improve the pre-judgment effect on the speed.Simulations were performed using Simulink and Lab VIEW software.The results show that compared with traditional governors,the speed regulation characteristics of ASD are significantly improved,the anti-jamming capability is significantly increased,and the change trend of the speed is predictable.Based on Lab No.13 gantry and PUMA platform,after completing the integration with the bottom layer,ASD acceleration and deceleration conditions and catastrophic load conditions were tested and verified,and the results were analyzed.The experimental results show that under the acceleration and deceleration conditions,ASD can predict and adjust the speed according to the second derivative of the speed,the response time is short,the filtering effect is good,and the speed curve is too smooth.In the sudden increase/decrease load condition,ASD can stabilize the speed transition by compensating the oil quantity.Even if the load suddenly rises in a short time,the rotational speed is still excessively stable,no abrupt change occurs,and the speed adapting condition can be automatically adjusted.This shows that ASD achieves the adjustment of the speed and is in line with the diesel engine speed characteristics,which proves the rationality and practicality of ASD technology.