Precision seeding requires that the corn drill drop seeds into the soil by a specific in-row spacing while its travelling speed fluctuates due to unevenness of the field ground.This paper presents a low-cost precision...Precision seeding requires that the corn drill drop seeds into the soil by a specific in-row spacing while its travelling speed fluctuates due to unevenness of the field ground.This paper presents a low-cost precision seeding control system for a conventional corn drill with mechanical metering devices of finger-pickup type.A median filtering method was implemented in the control system to process measurements from a rotary encoder in order to acquire stable values of the corn drill travelling speed.The metering unit was driven by an electric motor controlled by the metering ECU according to the actual travelling speed and the desired in-row spacing in real-time.A user interface was programmed to communicate with ECUs for configuring parameters and displaying operating information during working.The newly-developed precision seeding control system was first calibrated in terms of speed measurement and control for two ECUs.Experiments were conducted on a seeding test platform in the laboratory for evaluating its accuracy in dropping seeds by giving different in-row spacing under different travelling speeds of the conveyor sticky belt.Results showed that the average spacing error was less than 2 cm and the maximum RMS error was 0.78 cm for all spacing values including 25 cm,30 cm and 35 cm under the travelling speed of 1.0-8.0 km/h.These indicated that the low-cost precision seeding control system worked in a both accurate and stable way.展开更多
In this paper,the rapid and integrated manufacture method of 3 D printing gun drill is put forward.The 3 D printing process test of the composites gun drill composed of medium carbon steel drill shank,low alloy steel ...In this paper,the rapid and integrated manufacture method of 3 D printing gun drill is put forward.The 3 D printing process test of the composites gun drill composed of medium carbon steel drill shank,low alloy steel drill pipe and tungsten cobalt hard alloy drill bit is conducted.Microstructure and morphology of the composites gun drill interface between low alloy steel and tungsten cobalt hard alloy is analyzed using SEM.Element distribution and Phase composition of the interface between low alloy steel and tungsten cobalt hard alloy were tested and analyzed by EDS and XRD respectively.The oxidation resistance,micro hardness and corrosion resistance of the interface between low alloy steel and tungsten cobalt hard alloy were analyzed.The results show that the interface performance of 3 D printing composite gun drill is better than that of the welding gun drill.The rapid and integrated 3 D printing method is feasible for gun drill manufacture.展开更多
基金This research was financially supported by the National Natural Science Foundation of China(No.31501230)Shandong Province Natural Science Foundation of China(No.ZR2014CQ058)+1 种基金the National Key Research and Development Program of China Sub-project(No.2017YFD0700405)Shandong Province Science and Technology Planning Project of Higher Education(J17KA145).
文摘Precision seeding requires that the corn drill drop seeds into the soil by a specific in-row spacing while its travelling speed fluctuates due to unevenness of the field ground.This paper presents a low-cost precision seeding control system for a conventional corn drill with mechanical metering devices of finger-pickup type.A median filtering method was implemented in the control system to process measurements from a rotary encoder in order to acquire stable values of the corn drill travelling speed.The metering unit was driven by an electric motor controlled by the metering ECU according to the actual travelling speed and the desired in-row spacing in real-time.A user interface was programmed to communicate with ECUs for configuring parameters and displaying operating information during working.The newly-developed precision seeding control system was first calibrated in terms of speed measurement and control for two ECUs.Experiments were conducted on a seeding test platform in the laboratory for evaluating its accuracy in dropping seeds by giving different in-row spacing under different travelling speeds of the conveyor sticky belt.Results showed that the average spacing error was less than 2 cm and the maximum RMS error was 0.78 cm for all spacing values including 25 cm,30 cm and 35 cm under the travelling speed of 1.0-8.0 km/h.These indicated that the low-cost precision seeding control system worked in a both accurate and stable way.
基金supported by Key Research and Development(R&D)Projects of Shanxi Province(Grant No.201903D121054)supported by Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi(Grant No.2019L0621)。
文摘In this paper,the rapid and integrated manufacture method of 3 D printing gun drill is put forward.The 3 D printing process test of the composites gun drill composed of medium carbon steel drill shank,low alloy steel drill pipe and tungsten cobalt hard alloy drill bit is conducted.Microstructure and morphology of the composites gun drill interface between low alloy steel and tungsten cobalt hard alloy is analyzed using SEM.Element distribution and Phase composition of the interface between low alloy steel and tungsten cobalt hard alloy were tested and analyzed by EDS and XRD respectively.The oxidation resistance,micro hardness and corrosion resistance of the interface between low alloy steel and tungsten cobalt hard alloy were analyzed.The results show that the interface performance of 3 D printing composite gun drill is better than that of the welding gun drill.The rapid and integrated 3 D printing method is feasible for gun drill manufacture.
