直流电动机调速是指电动机在一定负载的条件下，根据需要，人为地改变电动机的转速。直流电动机调速调速性能好。所谓“调速性能”，是指电动机在一定负载的条件下，根据需要，人为地改变电动机的转速。直流电动机可以在重负载条件下，实现均匀、平滑的无级调速，而且调速范围较宽。(DC motor speed regulation refers to the fact that, under certain load conditions, the motor changes the motor speed art

当车门锁住之后利用人体红外传感器、称重传感器等传感器检测车内是否有误锁的幼儿，如果有则通过gsm模块发送报警短信，防止幼儿误锁车内。(When the door is locked, the infrared sensor, load cell and other sensors of human body are used to detect whether there is a child locked by mistake in the car. If there is, the alar