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Automated rubber tapping not only frees the workers from heavy physical labor and harsh working conditions, but also reduces the dependence on the workers' skills and greatly increases tapping efficiency. The key technologies for tapping robots are the independent acquisition of operational information and servo control of the tapping position in unstructured environments. In this study, taking rubber tree in rubber plantations as object, incorporating robot kinematics, machine vision technology and multi-sensor feedback control technology, a modular prototype of a rubber tapping robot was developed. The rubber tapping robot was mainly composed of an orbital mobile platform, a multi-joint robotic arm, a binocular stereo vision system and an end-effector. The binocular stereo vision and structured light system were used to obtain the structural parameters of the rubber trunk and secant. A six-joint tandem robotic arm was used for the planning and realization of complex rubber tapping trajectories. An multi-sensor fusion end-effector was developed to complete the identification of the starting point, the measurement of cut compensation and the tapping operation. To address the technical difficulties in rubber tapping operations, such as complex and variable environment, superimposed interaction of operational information, similar target background features and sub-millimeter operational accuracy requirements, the spatial mathematical model of the rubber tapping trajectory was established to plan the robot's movement path for fast approaching and moving away from the operation space. The results of the field tests conducted at a natural rubber plantation in Hainan province showed that the accuracy in bark consumption was about 0.28 mm and the accuracy in cutting depth was about 0.49 mm when the rubber tapping robot cut 1 mm thick bark. Compared to manual operations, the continuity of the chips and the flatness of the rubber output surface were improved significantly. This research could provide a positive reference and development direction for exploring automated rubber tapping operations.

To ensure food security and sustainable development of agriculture, it is critically important to develop organic agriculture and pollution-free agricultural products. Non-chemical weed control is important for organic agricultural production. Intra-row weeds are more difficult to be eliminated than inter-row weeds due to their proximity to the crop or seed line. Therefore, techniques for intra-row weed control remain to be one of the biggest challenges today. Efficient weeding robots can differentiate and remove inter-and intra-row weeds simultaneously, while identify and provide species information. The researches of intra-row weed control are more common in Europe because of their political interest and a push from the market. Nowadays, other countries, like the United States, Japan, Canada and China had carried out the researches in this area. This review describes the current state of the art of efficient weeding robots in detail to demonstrate the potential of the technology in the field. Several key technologies of weed control systems have been analyzed and compared. Three core technologies were summarized: guidance, detection and identification, and intra-row device. Row guidance which can use machine vision for crop row detection or GPS is an essential technology for weeding robot. Detection and identification which can identify and locate the crops in real time by three main approaches (computer vision, GPS and proximity sensor) is a critical technology. Furthermore, fusion of computer vision and GPS is seen today as the most promising strategy because advantages and disadvantages of absolute and relative referencing principles compensate each other. Intra-row device divided into rotation-type and swing type according to movements is a foundation of weed control. China is much later than the other developed countries in this area, but it has a booming development and grows rapidly. However, several technical problems exist as follows: 1) Recognition algorithm based on machine vision takes longer time, which makes the real-time of the system perform poorly; 2) Visual calibration method is cumbersome and complex under the non-structural condition; 3) The importance of intra-row weeding device development is ignored, weeding actuators directly affect weeding effect, the number and flow conditions of soil surrounding crops; 4) The hydraulic oil source is contaminated easily because tractor hydraulic oil is mainly used for lubrication; 5) Electric and pneumatic weeding robots are limited by poor battery life, and thus it is not available for field work; 6) The integrated performance of weed control system cannot meet the requirement of heavy load and efficient weeding in the field, and there still are some gaps between prototype and actual application; 7)There are less study on matching power system with speed of weeding robot that is the key to improve weeding precision and speed. According to the review, the further researches on weeding robots focusing on sensor fusion, efficient work, modular, miniaturization, high stability, and long life time have been proposed. With China gradually losing the advantage of cheap labor as well as sustained reduction of agricultural personnel, intra-row weeding robots are going to play an important role in agricultural production in China. [ABSTRACT FROM AUTHOR]

Under real-world driving conditions, the fuel and electricity consumptions of two parallel hybrid electric vehicles (PHEVs) are measured and their equivalent fuel consumptions are calculated with the methods recommended by SAE J2711 and GB/T19754 respectively to evaluate the fuel saving effects of PHEVs, and the effects of vehicle mass and air conditioner (AC) operation on the fuel consumption of PHEVs are also investigated. The results show that when K is less than 1%, the relative discrepancy between fuel consumptions in L/100km obtained as per GB/T 19754 (with electricity correction) and SAE J2711 (without correction) respectively is within 0.7%. PHEVs have obvious fuel saving over conventional vehicles with a fuel saving ratio of 14. 78% and 15.65% for two PHEVs respectively. And the equivalent fuel consumption in L/100km of PHEVs with AC on increases by over 42% compared to that with AC off. [ABSTRACT FROM AUTHOR]