Date: March 28th, 2021-03-28

Contribution: Organized according to media reports including Xinhua News Agency, Guangming Daily, etc.

Photography: Xinhua News Agency, project teams of BIT

[Editor's note]2021 marks the 100th anniversary of the founding of the Communist Party of China, and is also the first year of implementing the "14th Five-Year Plan" as well as a new start of comprehensively building a modern socialist country. Under the circumstance of carrying out party history learning and education, the Propaganda Department of the party committee has launched a special report on "Always Follow the Party and Forge Ahead in A New Journey", which fully demonstrates the school’s achievements in strengthening the leadership of Party and Party building as well as the people’s struggle in BIT, both of which have broadly gathered the majestic strength of the school's career development, and greeted the centenary of the Communist Party of China with outstanding achievements.

How to make the skating and skiing more accurate? How to train on snow in a non-snow season? To prepare for the Beijing Winter Olympics and improve the training level of winter sports events, led by Beijing Institute, a project named "Science and Technology Winter Olympics" has been steadily advanced in the past few years. One after another "black technology" has been or will be used in the China’s winter sports training to empower the "Technology Winter Olympics" and make athletes much faster and stronger in the ice and snow arena!

In less than a year before the Beijing Winter Olympics, BIT’s “black technology” project for the Winter Olympics has been deeply concerned and widely reported by CCTV, Xinhua News Agency, Guangming Daily and other media. Let’s follow the media to learn something about the behind-the-scenes heroes who are fighting on the front of the technological winter Olympics as well as their "black technologies."

"High-precision lens" tracking trajectories on ice

Liu Ming, associate professor of the Institute of Optoelectronics, is debugging the equipment

Recently, in the skating hall of the Capital Institute of Physical Education, Liu Ming, an associate professor at the Instrument Research Institute of BIT, has being led the team to test the equipment again and again. Image acquisition pan/tilt zoom equipment and ultra-high-definition cameras were erected on the stands. Liu Ming stared at the images of testers skating in the ice rink in the 4K monitor, operated the computer, and collected and analyzed their movement tracks.

This set of pan/tilt zoom, not that giant, is combined by two facilities that capture and collect the trajectories and processes of athletes on ice. "The pan/tilt zoom movement trajectory acquisition and motion capture analysis equipment has a zoom function, which adds an intelligent tracking algorithm and can follow the entire movement process of the athlete from the start of the race. The athlete’s size in the screen is relatively stable, so his image can be closed up more precisely. The technology not only enables a much easier extraction of its motion trajectory, but also captures the motion of its body parts. The ice rink panoramic image acquisition and motion trajectory analysis system can take a panoramic shot of the entire stadium because of its high single frame resolution. The rate can reach 25 million pixels and a frame rate of 160 frames per second, which can record the trajectory of high-speed athletes in large scenes. Although the accuracy is lower, it can measure multiple people at the same time." Liu Ming said.

What contributions the combination of the two facilities can make to the athletes? Liu Ming suggested that collecting the close-ups and trajectories of athletes can help athletes optimize their technical movements and train more scientifically and effectively. "For example, the system can analyze the position of the athlete's head and the head height from the ice surface when cornering, and can also help athletes adjust their body posture and balance more scientifically in training." Liu Ming said.

So, why not use high-speed cameras to make the tracking records? Liu Ming's answer is simple, his equipment is to make athletes and coaches feel easy to use. The common equipment on the existing market can meet the needs of multi-angle shooting and three-dimensional measurement, but the field of view is relatively fixed, and the recording range is relatively limited. If you want to record a larger site, you need to set up multiple sets of cameras covering different areas. The system is complex and The cost is very high, usually fixed installation in the ice rink and cannot be moved.

Liu Ming said that in order to break through these limitations, only the lens has gone through 7 versions from the beginning of research and development to the current product. "The first problem to be solved when applying pan/tilt zoom technology to machine vision is accuracy. The pan/tilt has angular accuracy, and the zoom lens has the accuracy of focal length change, so real-time data of focal length and magnification must be known at any time. The lens on the market cannot do it, so the turntable to the zoom system can only be done by yourself. Although the workload is large, the accuracy of the equipment is guaranteed. In addition, the algorithm, as an optical tracking system, interferes with and occludes the target. It is more sensitive. Once athletes occlude each other and the target is temporarily lost, the traditional algorithm will be messed up, so students have worked hard to improve it. At present, the function of continuous tracking with short-term occlusion has been realized, and it is still being improved." Liu Ming said.

"I hope that our equipment and products can be used as soon as possible in the teaching and training of ice sports and even track and field events to improve athletes' performance. This will be our greatest honor!" Liu Ming said.

Three-dimensional reproduction of "position to centimeter"

Associate Professor Zhang Haiyang School of Optoelectronics and UAV

Galloping at high speed on the vast snowy field, suddenly ups and downs, and suddenly turned sideways... At BIT, Zhang Haiyang from the research group of "3D Perception and Reconstruction Technology of Winter Project Scene" is showing on the electronic screen that it is built with a 3D radar scanning system. The scene of the Chongli ski resort is immersive and next to him are two drones equipped with radar systems.

"The Winter Olympics field has a large drop on the track. The athletes are dangerous throughout the course of skating and have high technical requirements. They need to overcome a lot of psychological pressure. Therefore, they can only skate a few times a day and consume a lot of physical energy. The simulation system can help them improve training efficiency Establish psychological expectations.” Zhang Haiyang said that the significance of the project is also to build indoor simulation scenes for athletes. After the team scans each scene, the VR team will intensively invest in the production of the simulation scene.

The athlete simulation training system has strict requirements on reconstruction accuracy, low temperature and real-time transmission, especially the challenge of low temperature. Some ski resorts have a radius of several square kilometers, and some have a drop of nearly a kilometer. The scanning efficiency of drones equipped with radar is higher, but the efficiency of drones below minus 20 degrees Celsius will decrease. For this reason, the team has also developed a suitable UAV-borne radar scanning system operating in low temperature environment.

The environment varies in different skiing fields. To achieve true restoration, a large amount of field data needs to be collected. To this end, the research team used drone-borne and vehicle-mounted radar systems to go to multiple ski resorts in Beijing, Hebei, Jilin and other places to scan and test data. They also collected information about their sports on the ski resorts through sensors worn by athletes, and then feedback to the display system.

The experience of braving the cold snow field is unforgettable for the team consists of 5 teachers and 10 students." At the beginning of January, the temperature of the Chongli Snow Field was minus 35 degrees Celsius. It was difficult for drones to meet the requirements and they could only be measured by the team of teachers and students holding the radar and braving the low temperature and severe cold. However, due to the undulations of the site and the shelter of vegetation, each step measured by radar is only 100 meters, so the boys in our team carried the equipment and the girls recorded the data, making full use of the interval between the athletes’ training and rest. The measurement was carried out on one slope after another and spent the whole day at low temperature. Our three-dimensional scene was completed in two days and handed over to the training team" said a member of the team.

"At present, our related results have been applied to the national team, which can reduce athletes' non-training injuries, improve sports efficiency, and provide technical assistance to coaches." Zhang Haiyang hopes that this technical achievement can benefit more athletes.

Indoor simulation "alpine skiing"

Cao Hongqing, a graduate student of the School of Automation, is experiencing simulated ski training

In a laboratory of Beijing Institute of Technology, graduate student Cao Hongqing of the School of Automation is wearing sensor equipment, stepping onto a 12-meter-long steel sliding table, stepping on a pair of simulated sledges on the sliding table, and facing the skiing scene on the huge electronic screen The screen began to sway rapidly from side to side.

Cao Hongqing participated in ski training especially for his participation in the research of "Indoor Multi-degree-of-Freedom Simulated Ski Training System" in order to personally test the effect of this indoor simulated ski training equipment. "I mainly do slewing exercises on the sliding table. It is tough to practice on it, but the experience of real skiing can achieve the purpose of ski training." He said.

The project is mainly to provide indoor simulated ski training equipment for athletes in alpine skiing, cross-country skiing and other events so as to improve the training efficiency of their special technical movements such as slewing and sliding. What’s more, by installing sports form recognition and pose measurement systems on the ski training platform, athletes' sports data can be collected and analyzed to provide guidance for scientific training.

According to Liu Xiangdong, head of the research group and professor at the School of Automation of BIT, the advantage of this equipment is that it enables athletes to carry out ski training indoors in non-snow seasons, and the sliding speed on the sliding table can reach a speed of 100 kilometers per hour. The 17 sensors on the joints of the athlete's body can accurately reflect their posture and movement data, helping the coach to evaluate the reference. In addition, the general-purpose product of this equipment is also equipped with a sports simulation platform under the sliding table, which has changes in height, tilt and deflection, and helps athletes train through various angles. Related equipment has been adopted in the daily training of athletes of the national alpine skiing team.

"The Beijing Winter Olympics are around the corner, and we hope that our research results can promote the training of athletes, help improve the training technology of the Science and Technology Winter Olympics, and make our contribution to the Winter Olympics." Liu Xiangdong said.

"Accurate to the muscle" intelligent training management system

The Sports and Cell Mechanics Research Group from the Academy of Astronautics is testing at the Jilin Beidahu cross-country skiing training ground

How does alpine skiing quickly bypass the flag gate? What is the most labor-saving posture for cross-country skiing? Which posture is best for ski jumping? How does speed skating train cornering skills? Professor Huo Bo is from School of Aeronautics and Astronautics of BIT, who leads the human motion mechanics team and focuses on four types of winter sports covering alpine skiing, cross-country skiing, ski jumping, and speed skating. Based on three-dimensional motion capture and automatic recognition technology, aerodynamic experiments and simulation technology, and physiological Sensor technology, musculoskeletal dynamics analysis technology, his team has developed the "Winter Event Intelligent Training Management System" to provide athletes with personalized and intelligent training programs.

“Ski jumpers should reduce their body's center of gravity as much as possible to reduce air resistance during the ski assist phase before the take-off phase, and at the same time, they should also extend their knees appropriately to improve the extension of their limbs after leaving the stage. Appropriately reduce the extension speed of the hip joint and reduce the wind resistance of the trunk. In daily physical training, athletes should emphasize on improving the explosive force of the lower limbs while avoiding excessive knee joint valgus, and improving the strength and transmission efficiency of pedaling and extension.” This is an intelligent sports management proposal issued by the athletes of the national ski jumping team.

"The system can collect in real time the three-dimensional posture parameters of athletes in multiple special actions in different sports, as well as the ground reaction force and air resistance generated by the actions, by which the athlete's dynamics database is formed and therefore can be used for subsequent sports biomechanics analysis and the formulation of training programs." Team leader Huo Bo introduced.

In addition to collecting athletes' dynamics data, using wireless transmission of myoelectric sensors, the "Physiological Parameter Monitoring and Sports Biomechanics Analysis Training System" developed by the team which can realize real-time physiological sign detection through collecting athletes under various special actions. In the process, biomechanical model of the skeletal muscle system is established to analyze and evaluate the athletic ability of athletes.

From January 8th to March 24th, 2021, Professor Huo Bo led a team of 7 teachers and students to the Yanqing Arena and started the technical service of the Winter Olympics test snowmobile sled team. Focusing on the technical requirements and project characteristics of the National Snow Team and the National Steel Framed Snow Team, the team conducted tests and analyses on the athletes' performance in the starting and corners during daily training and test competitions.

"This year, we spent a special Spring Festival with the national team. Although it is tough, I still feel full of power because since we are making contributions to major national events." Jiang Liang, a doctoral student of the team, said.

Equipped with an "instant accelerator" for speed skating

The human body high-speed ejection device is being used by coaching staff of the national speed skating team to carry out simulation training

The key for a successful speed skating is to master the sliding technique at the curve. The "human body high-speed ejection device" developed by the Beijing Institute of Technology's aerospace launch technology team can assist speed skaters in the curve sliding technique training, achieve precise control of the acceleration process, and fill the domestic gap in this field.

The subject is mainly completed by Hao Jiguang, the teacher of BIT, who said that in the past, athletes used the train corners technology by accelerating the speed into the corner, while the process of accelerating to a high speed is very physical. Therefore, plenty of corner training ae usually designed for athletes before starting a big competition. In addition, the speed reached due to each accelerating has also related to the athlete's physical state, and the training is not accurate enough.

"We are expecting to use the ejection launch principle to speed up the athletes and let them experience the world-class speed'." Hao Jiguang said, since the ejection launch technology in the school's aerospace launch technology major is very similar to the needs of this project, the team began to develop a "human body high-speed ejection device", hoping to use the device to pull the athletes to achieve instant acceleration.

After a complex processes of principle design, prototype design, prototype trial production, and various functional experiments, counterweight experiments, and human experiments, the first device of the "human body high-speed ejection device" was successfully made in April 2019. This device enables speed skaters to slide off at a speed of up to 20 meters per second. Assisted by the device and in just a few seconds, the speed skater can reach a designated speed from a standstill state, during which he can adjust his posture and enter a corner at one time.

At present, the "human high-speed ejection device" has been used by the national speed skating team for several times to carry out practical training and trained operators for many teams. Now, it has become one of the daily training subjects of the national team using this device to carry out corner training.

Practice has certified that the "human body high-speed ejection device" can not only save about two-thirds of the training time for special technical actions such as assisting sliding and jumping, reduce the athlete's physical consumption, but also achieve precise control of the acceleration process so as to improve the training efficiency and effectiveness of the athletes.

In addition to speed skating, the human body ejection device for ski jumping has also been successfully developed. It will be installed and applied in the near future and will enable ski jumpers to slide off at a speed of up to 30 meters per second, providing technological support for the success of the Winter Olympics.

“Cold-Resistance” Electric Car for the Beijing Winter Olympics

Academician Sun Fengchun is making a test on extremely cold environment

"Data is convincing only when it is completely frozen." At 4 o'clock in the morning on January 19, 2020, on the ice lake in Yakeshi, Sun Fengchun, a professor at the School of Machinery and Vehicles of BIT and an academician of the Chinese Academy of Engineering, led the team again to make the final field test for the winter Olympics domestic new energy vehicle technology in extremely cold environment. In order to challenge the extreme conditions, Sun Fengchun insisted on parking the vehicle on the ice for three nights in advance to ensure that the vehicle could be completely frozen.

"Beijing 2022 Winter Olympics must achieve full coverage of new energy vehicles, which poses a historic challenge to the overall performance of pure electric vehicles." Sun Fengchun suggested. Zhangjiakou is the host of the Winter Olympics snow project where the minimum temperature can reach minus 20 degrees Celsius in winter. "Under low temperature conditions in winter, the power battery cannot be charged and discharged, the vehicle cannot be cold-started at a low temperature, and there’s high heating energy consumption. This is a worldwide technical problem for pure electric vehicles."

"Without foreign aid, there is no pure electric vehicle in the world that can be started by itself after being placed in a place of nearly minus 40 degrees Celsius for 72 hours." Sun Fengchun said, "We did it in 2018." From 2018 to 2020, the team has been to Yakeshi three times to conduct extreme cold tests on key technologies of new energy vehicles where the minimum test temperature is close to minus 40 degrees Celsius.

"Our mission includes both basic scientific research innovation and engineering technology innovation, which finally must be implemented in mature vehicle products." Team member and Professor Lin Cheng from the School of Machinery and Vehicle of Beijing Institute of Technology introduced. The team experienced two extremely harsh years of 2016 and 2017, during which weI first cooperated with a Chinese-American scholar to solve the low-temperature battery technology problem, cooperated with BAIC New Energy and Beiqi Foton to deal with the technical problem of the whole vehicle, and worked with Hunan Huaqiang to solve the problem of vehicle technology. The time requirements of the Winter Olympics project cannot be altered, and only what we can do is to continue to tap our potential and creativity."

Under low temperature conditions, the air-conditioning efficiency of new energy vehicles becomes a main concern for car owners. "This is a big challenge for the entire automotive air-conditioning industry." said Luo Yuehua, a team member and chairman of Hunan Huaqiang Electric Co., Ltd., "After a three-year technical research, the team has achieved a temperature of minus 30 degrees Celsius in the car in 2020. At this time, and the car air conditioner can still operate reliably. From now on, the new energy car air conditioner will no longer be restricted by low temperature.

As a developing country with a large population and limited energy, China has a broad market demand for pure electric buses. "The new energy vehicles with China's independent intellectual property rights will not only effectively serve the Green Winter Olympics, but will also completely solve the problem of the promotion and application of new energy vehicles in the northeast, northwest or alpine regions, and China's new energy vehicles no longer have restricted areas. "Sun Fengchun said.