In order to improve the adaptability of unmanned wave glider to complex sea states, a reduced-order extended-state-observer-based line-of-sight (ELOS) guidance law is designed for the adaptive path tracking control problem of UWG. In this ELOS guidance law, the reduced-order extended state observer is introduced to estimate the time-varying sideslip angle, so that the unknown time-varying sideslip angle can be compensated, which improves the control performance of the system and accelerates the convergence speed. The stability analysis and simulation comparison experiments verify that the control method designed in this paper has good robustness and a significant control effect.
In order to efficiently and accurately identify and detect pavement cracks, this study proposes a pavement crack detection algorithm based on an improved Yolov5s network model. The algorithm introduces a weighted bi-directional feature pyramid network BiFPN as a neck feature network for fusing feature maps of different dimensions, thus enhancing the bottom feature information and improving the feature aggregation effect. In addition, CBAM, an attention mechanism, is employed to enhance the learning and extraction of feature information from the pavement crack image, while attenuating the influence of the pavement background, which is similar to the crack, on the detection results. The experimental results on the homemade dataset show that the improved yolov5s model improves 10%, 2.2%, and 4.6% over the original model in terms of precision, recall, and mean average precision values, respectively. This indicates that the improved algorithm is feasible for pavement crack inspection.
In this paper, the identification system of sugarcane was studied based on the pre-seed cutting sugarcane planter developed in the laboratory to solve the problems of uneven cane discharging and high seed leakage rate. Firstly, simple structure analysis and system design of sugarcane planter are carried out. Secondly, histogram equalization algorithm is applied to enhance the image based on the real-time feedback of the camera. Thirdly, the template matching method is used to extract sugarcane images. Finally, the obtained sugarcane images were morphologic processed to obtain the surface texture information of sugarcane, and the information of sugarcane body and sowing situation were recorded through system recognition feedback.
The object detection algorithm has experienced the transition from the traditional algorithm to the object detection method based on convolutional neural network. The traditional object detection algorithm mainly includes VJ detector, HOG, DPM, etc. It mainly uses the sliding window method to detect and locate the object, and there is a certain bottleneck in the running speed. With the increase of training data and computer performance, the object detection algorithm based on deep learning has a good effect in both detection accuracy and detection speed, and has become the mainstream algorithm of object detection. Through the author's own understanding, this paper summarizes various object detection algorithms in a more understandable language.
The hydraulic module of hybrid electric vehicle is used for shifting and clutch driving control of electric drive gearbox of hybrid electric vehicle. The most important part of the hydraulic module is the hydraulic system. First of all, the analysis of the hydraulic module in the hydraulic system schematic, secondly, through theoretical calculation of the pump and valve mathematical model, again, the use of Simulink platform to establish a dynamic simulation model of the hydraulic system, finally, through the simulation of the pump and valve with the working time of the system oil diagram, and dynamic analysis of the system. To achieve the new energy vehicle electric drive gearbox shift and clutch drive control performance judgment.
As a core component of the vehicle transmission system, the wet clutch is widely used in cars, heavy vehicles and tracked vehicles, whose dynamic engagement characteristics affect directly the safety, comfort and durability of the vehicle. In this paper, the meshing process is simulated by finite element method. In the fluid friction, the average Reynolds equation proposed by Patir and Cheng is improved, and dimensionless parameters are adopted, which is applied to calculate the viscous torque. In the boundary friction, a surface elastic contact model is established to calculate rough contact torque. In the mixed friction, total torque consists of viscus torque and rough contact torque. The simulation and bench test are completed to verify the validity of model proposed. Model proposed can be used to guide wet clutch design in early stages of product development.
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