【目的】针对链式开沟机开沟深度难以精确调节的问题，设计一种基于激光传感器的开沟深度控制系统。【方法】采用激光三角反射式位移传感器实时检测开沟深度，并与设定目标值比较；通过控制系统决策驱动液压系统与执行机构，实现开沟深度的闭环控制；通过田间试验，比较了开沟深度控制系统开启前后控制精度和稳定性。【结果】静态试验结果表明，当开沟深度检测值与目标值相差±50 mm时，系统响应时间分别为0.19和0.31 s，最大控制误差3 mm。田间试验表明，开沟深度分别为200、300和400 mm，前进速度为3 km·h–1时，启动开沟深度控制系统后，链式开沟机开沟深度的控制精度和稳定性均得到提高；与关闭系统相比，启动系统后控制精度提高了2.3%，稳定性系数提高了4.3%。【结论】该控制系统响应迅速、控制精度较高，控制误差满足了设置要求。研究结果为链式开沟机开沟深度控制提供了一种解决方法。
【Objective】To design a kind of trenching depth control system based on laser sensor,so as to solve the problem that it is difficult to adjust accurately the trenching depth of chain trencher.【Method】The laser triangular-reflecting displacement sensor was used to detect the trenching depth in real time, which was compared with the target value. The closed-loop control of trenching depth was realized by the control system making decision and driving hydraulic system and actuator. The field experiment was conducted to compare the control precision and stability before and after enabling the system.【Result】The result of static test showed that when the different values between the detection depth and the target depth were ±50 mm, the response time of the system were 0.19 and 0.31 s respectively, and the maximum control error was 3 mm. The field test showed that when the trenching depths were 200, 300 and 400 mm respectively at the speed of 3 km·h-1, the control precision and stability for trenching depth of the chain trencher were improved after starting the control system. Compared with closing the system, the control precision and stability coefficients increased by 2.3% and 4.3% respectively after opening the system.【Conclusion】This control system responds quickly with a high control accuracy, and the control error satisfies the set requirements. The result provides a solution for controlling the trenching depth of the chain trencher.