Purpose: substantiation of the design of the cutterbar of the header, providing high indicators of its maintainability and quality of sorghum harvesting. Materials and methods: scientific works on research of cutting devices of headers for grain and forage harvesters were used. In the 2020 harvesting season, the timing of the operation of a sorghum harvester equipped with a segment-finger cutter with an endless knife contour and a segment failure control device was carried out for harvesting grain sorghum of the Premierra variety, on the basis of which the laboriousness of restoring parts and assemblies was determined of the improved cutterbar, an assessment of the quality of plants cutting and grain losses is given. Results. The basic requirements for the design of the cutterbar of the header are given: to ensure high quality of plants cutting of various crops and varieties of agricultural crops; to have low energy consumption, high reliability of the structure in a wide range of operating conditions and high technological performance; to be compact and safe to maintain. The design of the cutting device of the header is proposed, which contains a knife in the form of a chain circuit with segments, a knife drive, a sensor, a control unit, a signaling device, a drive with a brush, while the header speed sensor and an analog-to-digital converter are additionally connected to the input of the control unit, and to the output - a control unit, functionally connected to the chain circuit drive. In the event of segment failures, the control unit receives a signal corresponding to the time the sensor travels a distance equal to the segment setting step on the chain loop tfact.. The control unit compares tfact. with a given t0. If tfact. > t0, then the frequency of rotation of the drive shaft increases until the moment when tfact. = t0. The linear speed of the segments is maintained at the achieved level. When a signal arrives at the control unit corresponding to the time tfact. < tmin, a signal is sent to the control unit to turn off the drive of the chain loop. Experimental studies of a sorghum harvester have shown that the average labor intensity of restoring an improved cutting device is 2.2 times less than that of a segment-finger one. In addition, it was found that the cuttingedge of the header of the proposed design allows mowing broom and grain sorghum at a given cutting height with high quality in case of failure of up to three adjacent segments. Conclusion: a new design of the cutterbar of the header with an endless knife contour, sensors for segment failures and header speed, a control unit, a signaling device, an analog-to-digital converter and a control unit has been proposed, which has the ability to automatically regulate the linear speed of the segments of the ensuring the quality of the cut of plants, determined by agrotechnical requirements.
A Survey on Analog-to-Digital Converter Integrated Circuits for Miniaturized High Resolution Ultrasonic Imaging System
