2 results about "Proportion integration differentiation" patented technology

The invention relates to the field of engine exhaust gas recirculation rate control, in particular to an engine exhaust gas recirculation (EGR) valve closed-loop control system which comprises an EGR valve, a target EGR rate selection module, an actual EGR rate measurement module and a proportion integration differentiation (PID) controller. The target EGR rate selection module stores target EGR rates under different work conditions, the actual EGR rate measurement module can measure the actual EGR rate of an EGR valve under the current work condition, the actual EGR rate measurement module can send the actual EGR rate under the current work condition to the PID controller, and the target EGR rate selection module can send a target EGR rate corresponding to the current work condition to the PID controller. If the actual EGR rate and the target EGR rate are identical, the EGR valve remains valve core opening degree. If the actual EGR rate and the target EGR rate are different, the valve core opening degree of the EGR valve is adjusted so as to adjust the EGR rate. The system can monitor the EGR rate in real time, guarantees that the actual EGR rate and the target EGR rate are identical, enables an engine to be in the best condition and improves gasoline combustion performance.

Disclosed is a method for identifying grass conditions based on the motor load by a mowing robot. A processor for central control is arranged on the mowing robot, and is connected with a motor controller. The motor controller is connected with a mowing motor, the mowing motor is connected with a mowing mechanism, and the grass condition identification method is set in the processor. The method includes the following steps: starting a PID (proportion integration differentiation) controller to set the speed of the mowing motor to be V; measuring the PWM (pulse-width modulation) output as D undera no-load condition; if the PWM value output by the PID controller exceeds a set value, determining that grass flourishes at the current position; allowing the mowing robot to reciprocate in situ until the PWM value output by the PID controller returns to normal. The method has the advantages that the grass conditions at the current position can be directly determined, the working mode of the mowing robot can be guided, and accordingly, the working efficiency is improved.