During the execution of autonomous tasks within sheltered space environments, unmanned vehicles demand highly precise and seamless continuous positioning capabilities. While the existing visual–inertial-based positioning methods can provide accurate poses over short distances, they are prone to error accumulation. Conversely, radio-based positioning techniques could offer absolute position information, yet they encountered difficulties in sheltered space scenarios. Usually, three or more base stations were required for localization. To address these issues, a binocular vision/inertia/ultra-wideband (UWB) combined positioning method based on factor graph optimization was proposed. This approach incorporated UWB ranging and positioning information into the visual–inertia system. Based on a sliding window, the joint nonlinear optimization of multi-source data, including IMU measurements, visual features, as well as UWB ranging and positioning information, was accomplished. Relying on visual inertial odometry, this methodology enabled autonomous positioning without the prerequisite for prior scene knowledge. When UWB base stations were available in the environment, their distance measurements or positioning information could be employed to institute global pose constraints in combination with visual–inertial odometry data. Through the joint optimization of UWB distance or positioning measurements and visual–inertial odometry data, the proposed method precisely ascertained the vehicle’s position and effectively mitigated accumulated errors. The experimental results indicated that the positioning error of the proposed method was reduced by 51.4% compared to the traditional method, thereby fulfilling the requirements for the precise autonomous navigation of unmanned vehicles in sheltered space.
Through analyzing the connotation of the innovative learning and innovative talents, we get the main characteristics of the innovative learning in four respects: first, at the concept of thinking, dissatisfied with the existing knowledge and planning the future development; second, at learning attitude, combining the scientific thinking with the exploration for oneself;third,at learning activity,good at absorbing other's wisdom;fourth,at learning quality,extensive knowledge and special knowledge are joined to activate it.
Fire forces hold great responsibilities of and fire supervision,fire fighting and rescuing,the disaster relief at the same time.The ideology,the behavior and value,the mental health of fire forces have changed greatly in this new age.Mental pressure has become bigger and bigger resulting in weakening the fire fighting power of fire forces.This paper explains the significance of mental healthy management and put forwards some suggestions.
Internet is a technology open to the all users through sharing the network resources. And the share is in contradiction with the network security. This leads to the growing problems in network security. In this paper, the ever-growing threat to the network security is analyzed, the requirement and the key technology of network security are introduced.
It is a good example of integrating modem information technology with the course teaching reform to use information technology to create a new research teaching model.This paper integrated modem information technology with teaching model of the course to create a new teaching model of the course on the basis of CAI technology,constructivism and teaching target of the course and the characteristics of information technology.In the paper the author constructed a whole target and implementation of teaching project of the integration of ordinary differential equation and information technology,and a concrete teaching method with setting up the situation,exploring the new knowledge,applying simply and evaluating is also provided.
In order to correctly evaluate the effect of straw returning in agricultural production,the effect of straw returning on soil quality was introduced from three aspects(soil fertility quality,soil health quality and soil environmental quality),and the prospects of straw returning were viewed.
This paper analyzes the insufficiency in the law system about inside dealing of securities in China.The concept of inside information and identification of inside staff is clearly explained.Furthermore,detailed suggestions are also provided for building up the civil compensation responsibility system of our country's securities inside-dealing
The financial service system of village is distempered.It is an important factor that restricts the development of village economy of our country.In this paper the problem that existed in the financial service system was analyzed and the reform of rural credit cooperative was suggested.
The national spirit is the spiritual support for a nation to exist and develop. Raising the national quality is the fundamental guarantee to build a well-off society in an all-round way, of which the national spirit is the core and the soul. It is an important mission for colleges universities to raise the young students' cultural quality, as well as develop and cultivate their national spirit. Colleges universities should take the mission of developing and cultivating the national spirit as their important task, and carry out a lot of work full of distinguishing features combined with their own actual situation.
Abstract Focusing on the problem of inefficiency and labor waste in contact and sensing crop altimetric methods, a method is proposed for crop height measurement using machine vision. Firstly, a crops height measurement model was established based on aperture image principle, and then segmentation lines extraction of crops and background was implemented by a series of morphological operations. Secondly, the foreground information is segmented according to the H channel in the HSV color space. To help extract the complete crop area, a global scan was performed on the image using multiple images to obtain a segmentation threshold with a certain fault tolerance, and the inter-frame sum method and large-scale filter template are also adopted for image enhancement. Considering of the uneven height lines and porous holes in the crop area, the boundary line between the crop region and the background is strengthened through morphological operations such as dilation and erosion. Finally, the Sobel operator is applied to detect the horizontal line. The parameters of the height line could be calculated, and thus achieving crop height measurement. Experiment results show that the inter-frame enhanced image is filtered using the median and morphology of the large-scale window, and the complete upper boundary line of rice and wheat is obtained through hole filling to realize height measurement. Average error of crop height is less than 1.6%, and processing time per frame within 50 ms.
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