Kinematic diagram of the mechanism and algorithm for controlling the width of the indoor structure exhaust opening

Abstract

The results of theoretical studies of the possibility of reducing the lack and excess of heat in the cultivation structure by substantiating the parameters and algorithm of the mechanism of real-time control width of the exhaust opening are presented. A kinematic diagram of a flat lever mechanism for controlling the width of the draft opening with a drive from an electric linear actuator has been developed. Dependences of the angle of inclination of the leading link of the mechanism and the width of the exhaust opening on the stroke of the actuator rod are determined. The maximum travel of the actuator rod is 225 mm, which allows you to change the width of the exhaust opening from 0 to 900 mm. In this case, the angle of the axis of the master link position sensor varies from 0 to 90 degrees. Based on the analysis of the operation process of the mechanism and the requirements of the plants to the ambient air temperature, an algorithm for controlling the width of the opening was developed, providing for three possible situations. As long as the air temperature meets the biological requirements of the plants, the width of the exhaust opening does not change. If the air temperature exceeds the upper limit, the width of the opening is increased by the value determined by the angle change step of the mechanism driving link. If the air temperature is less than the lower limit, the controller turns on the linear actuator to reduce the opening width. This ensures that the tilt angle of the master link changes by the step dA, which is set during the programming. Logic operators compare the current value of the angle of inclination of the master link with the calculated value and switch the actuator on and off. Thus, the proposed algorithm consistently approximates the state of the system to the optimum zone and reacts to the changes in external conditions.