Lei Feng network (search "Lei Feng network" public number concerned) : Author of this article YY Shuo, from the Xinjiang engineers. The original title of "Robot Engineer Learning Plan" is full-length. For ease of reading, it is divided into three parts. This is a middle article.
JuniorAt the beginning of junior year, you can play an important role in the school's robot team, or can lead a small team to participate in a small robot game. You are very famous in the department and even in the courtyard. Some people may call you a god. Some people think that you have a good technique. But be sure to remember that your current level should not be anything else. Each year, I recruited 100 students from the RoboMasters summer camp in Dajiang.
Editor's Note: The RoboMasters Summer Camp is a summer research activity that was designed by Dajiang for science students and robot lovers. Through the self-registration form, more than a hundred students from major universities and colleges are invited to conduct one-month project training at the headquarters of DJI. The professors and industrial industry elites of Hong Kong University of Science and Technology conduct the guidance and grouping. Finally, each group conducts its own research. The results are verified.
The junior must cultivate his own ability to build a complete robot independently, such as a Robocon-level robot, a RoboMasters chariot, or a quadrocopter.
Robocon level robots involve a large number of mechanical designs, microcontroller development, development of motor drives, reading of sensors such as encoders and ultrasonics, calculation of chassis kinematics, PID debugging, debugging of task scheduling logic, and servo control. The mechanical part of the chariot of RoboMasters is simpler, but it also requires knowledge of PTZ control, launching system control, power control, etc. In addition, you can learn to learn visual recognition and automatic attack by not using these parts. It is time to start researching OpenCV.
The mechanical part of the quadrotor is the simplest, but the algorithm is more complex. For juniors, it is more difficult to write a stable flight control from scratch, because there are many small knowledge points in the flight control. At present, I have not found any good book recommendation. Some existing books on the quad-rotor system are either too shallow (to teach you to solder the circuit), or too deep (to teach you state estimation), and I heard @Liu Top's exbot. The team is writing a textbook. I am very much looking forward to it. There are the following steps to learn about quadrotors:
The first step: make yourself a small four-axis fly
People in the open source community are now saying that pixhawk is, in fact, I think from a learning perspective, pixhawk is too expensive and not suitable for learning. I would recommend the STM32F405 flight controller sold by the Taobao Store in the seventh lab. Buying a rack (such as the Dajiang F450), a receiver, and a remote control, you can fly with the learning materials and debugging software attached to the flight control board.
Step 2: Look at the hardware diagram and read the code
The chipboard7's flight control board comes with a lot of learning materials, and it has very detailed explanations for accelerometers, gyros, and magnetometers. The hardware link diagram is also very detailed. Chiplab7 Taobao dispensers is very serious and responsible, I learned when used, found that the code has bugs and can not understand the place, you can ask the treasurer directly.
After reading the code, it is clear to the basic modules of a flight control system: attitude calculation, control solution, mixed-control output, remote control processing, and embedded processing. However, there are many technologies in this area that need to be learned in addition. In addition to basic embedded programming, there is a need to look at the signal processing aspects of sophomore year and junior high school. Because the aircraft has vibration in the air, it will make the accelerometer produce noise. In order to remove these noises, the signal given by the accelerometer needs to be low-pass filtered. How to select the parameters of the filter? If the filter is filtered too far, the delay will be large, which will have an effect on the performance of the control. If the filter is not filtered enough, some low-frequency noise may occasionally appear, making the observation of the accelerometer impossible. In addition, the most important thing is to understand the two pieces of knowledge of attitude solution and control solution. The chipboard7's flight control board code uses the simplest complementary filter algorithm as the attitude solver module, and then the control solution is a closed-loop PID control of the three angles of the Euler angles. Basically, this is the basic foundation.
The third step: make minor changes and deepen understanding
The flight control of chiplab7 is based on the barometric pressure gauge, and the flight effect is very unrestrained. At this time Taobao can buy a $ 20 ultrasonic module, and then write a high degree of self-stabilization of the flight control of the fixed-high performance.
I think this process is very important, because the height control is a relatively intuitive way to understand the PID control, and the flight control and height control of the chiplab7 is very good. The workload is not great, because the improvement effect is significant, so it can make people feel great and deepen the fun of continuing to learn.
Step 4: Understand core math and control knowledge
This part of the junior year is definitely too late to learn, but I'm still here to list, because the knowledge you need to learn later, I will continue to repeatedly mentioned these knowledge points.
The knowledge involved in attitude solving and control solution include:
1. The expression of rigid body posture, kinematics equations and dynamic equations. It is mainly about the understanding and understanding of the Newton-Euler equation, the Euler angle representation of the rigid body gesture, the relationship between attitude and angular velocity, and so on.
This part says that the complexity is not complicated, and that it is not simple. I also failed to find a complete book that was introduced. I learned several different books and dissertations later. Now it looks like starting from Wikipedia is more reliable.
2. The principle of automatic control. The books and articles that deal with PID are more than that. There are not many complicated books.
3. The basic principle of linear estimation. In fact, complementary filtering: Reading a IMU Without Kalman: The Complementary Filter. Take this keyword Baidu search will be.
Step 5: Start heavy-headed
Known to the famous netizen vczh once said that learning must hold the courage to create a wheel in order to progress. So on the basis of familiarity with other people's flight control, you can build a flight control wheel yourself. You can start to redraw a flight control board from the chip, read the STM32 chip manual, read the chip manual for various sensors, draw a schematic of the flight control, do the PCB layout, make the board's own welding components, and use the full set of flowers. Not 1,000 dollars, can deepen a lot of understanding of the hardware. If this year's junior year is not available, this part can also be avoided.
The process of manufacturing the entire robot must pay special attention to the accumulation of documents. At the end of your junior year, you may be preparing for the game with the school's robot team. You may be responsible for a robot. You should list an excel yourself and use a few screws, a few wires, and what the specifications of each part are. This table can be used to help the team manage the robot's materials on the one hand, and on the other hand, it is also your own accumulated experience technology. In the future, other robots you make may be more or less the deformation of Robocon and RoboMasters robots.
Another accumulation is to build a bug list of your own. What does the buglist include? It can be like cold and big. In the answer to “What kind of experience is the algorithm engineer doing control, robotics, etc.?â€, simply put some of your own The problem and the final solution are listed. For example, “DuPont's wire insertion is unstable and it is easy to disconnect. After it is connected, it should be wrapped with electrical tape.â€, “The mechanical drawings sent to Taobao processing should pay special attention to the details of the communication with the processor. , such as countersunk screw holes, key chamfers, etc. You can also make other records of other robot problems. A buglist can be a simple text file. If you keep accumulating records from your own work and wait for you to work in the future, the file may be worth a lot of money.
In junior year, schools should open software engineering courses. Whether you are in this profession or not, you should take the initiative to listen to it and even do it with the design work of the course. Software engineering I think is a robot engineer must have the consciousness, because a robot system involves a large number of hardware systems and software features, the software part often involves different languages, different compilation environment, different development tool chain. When several people collaborate, everyone's professional background and programming habits are different. This results in very complicated communication between different codes and modules. Therefore, UML and other software engineering tools must be used as soon as possible to help the team understand and communicate with each other.
In junior year, the school should also open courses on operating system principles and embedded system principles. In his sophomore year, he explained the principle of computer composition (the so-called microcomputer principle). From the junior year, students need to begin to understand the difference between the real-time operating system and non-real-time operating system, the principle and the need to pay attention when using. This is a relatively complicated knowledge point. I have not found a good teaching material to introduce it. On the STM32, there are several real-time operating systems such as freeRTOS, uCOS, and Vxworks. Linux is a non-real-time operating system, but it can be changed into a real-time operating system by patching. The details of these operating systems are more or less involved in the development of robots. Students can go to Google and CSDN at any time to check out the introduction of the gods.
Another very important point is that the embedded platform in the robot system has the possibility of burnout. It is possible to write a month code on an embedded Linux platform. The platform suddenly burned out, and the code also Lost. Therefore, if your robot has an embedded Linux system in it, it must be jacked up as soon as possible. The code should be submitted periodically to SVN or git.
During the junior summer vacation, you may participate in the competition as the main school robot team. Preparing for competitions and competitions is a heart-rending thing. I experienced the pain of passing through the students' experience and victory. I felt that I had no chance to regret for another year. I was also touched by the painful and regretful students who were responsible for venting during the game of the RoboMasters. . I think it was a fast-growing thing to participate in robot competitions and work hard and fail. If students have the opportunity, they must participate in at least one robot competition.
You can also choose to attend the RoboMasters summer camp in Dajiang during your junior year vacation. You can read this Q&A for summer camps to find out more: What is the experience of participating in the Robomasters 2016 Summer Camp? Every year, we look for students with a certain technical foundation across the country and let them group together to make an automatic robot challenge. This summer camp, as the head of the organization, is not humble enough to say that I think it should be the best technical summer camp in the world.
Editor's Note: This year's RoboMasters summer camp competed for understanding of machine vision technology and challenged the robot's automatic flight, automatic retrieval, and automatic throwing techniques. The picture shows the challenge robot grabs the doll and is ready to put into the corresponding color box. In this process, the robot is fully automatic. The robot needs to visually recognize the color of the doll and the color of the frame.
One of the most important things for a junior's summer vacation is to think about what my senior year should be. In general, your current ability to protect graduate students is certainly not a problem. Of course, you can also choose to study for graduate students in other schools or study abroad. Although you are very capable now, it will take 2-3 years for you to fully enhance your ability to move toward excellence. Regardless of whether it is going abroad or researching, the most important goal is to strive for themselves to be able to improve themselves in an excellent environment in the next 2-3 years. There are relatively good learning resources and they can participate in some good projects. It may be that there are other professions, studying abroad is always better than staying at home, but the robot industry is not the case. Our country’s robotic advancement in these two years has also been rapid, and our country is now richer. As I started to say, robots are the activities of rich people. Now you can find some very expensive laboratories in the country that can build more powerful robots. In addition, many relatively strong robot companies in foreign countries are also doing relatively sensitive military projects. There may be restrictions on finding internships.
Going abroad to learn about robotics you have a lot of good choices, such as Carnegie Mellon University, the world's number one robotic institute, or CSAIL Lab, Massachusetts Institute of Technology. In addition to Stanford University's enthusiasm for artificial intelligence, the robotics research in several other schools is very good. The four famous universities of North American traditional computers (Massachusetts Institute of Technology, Carnegie Mellon University, Stanford University, and University of California, Berkeley). In addition to the four prestigious universities, you have many other choices. As I said, robots are the activity of the rich. If you want to get access to the best robot resources, you have to choose a rich laboratory instead of a famous one. Laboratory.
In addition, you also need to select your future research direction for subdivision on the tail of junior year, and start digging in this direction, which is the direction of perception, recognition, and behavior that I mentioned in the article. Of course, at the same time you cannot relax other aspects of knowledge, especially the basics of mathematics. In the summer vacation of my junior year, I was specifically looking for mathematics classmates to give me a small mathematics lecture, learning a bit of abstract algebra knowledge, and helped me learn cryptography. At the same time I also read some topological textbooks (a fantastic book called Topopogy Without Tears) to understand why mathematical analysis uses strange symbols to explain some seemingly simple truths.
What basic mathematics is to be considered by junior robotics engineers in the junior stage is different. In my opinion, you have to master the basics of what the group is. You can use algebraic vision to prove that "det(AB) = det(A)det(B). ")", but also to understand "with a piece of paper can change the Klein bottle" (of course, in the four-dimensional space). In addition, you also need to be aware that you need to learn linear algebra again.
SeniorAfter the senior year begins, you can start digging your research direction. At the same time, you must begin to learn some advanced general techniques and theories. At this time, you are not the same as general mechanical, electronic, and computer students. Mad programming, but also mad learning physics and mathematics. Common technologies include tools such as ROS, simulink, gazebo, and Vrep. The general theory consists of studying linear algebra again, learning convex optimization, numerical calculation, rotational representation, and other aspects of knowledge. You only have a head start on this knowledge in your senior year. Because your senior year will require internships, graduations, postgraduates, and graduates, you will be very busy. Some people will write papers in the big four labs and teachers. I personally feel that there is no need to worry about essays. During your entire university period you should use a wide range of knowledge, rather than a detailed research question.
Seniors can begin to read some famous introductory books. I have listed these books in an indefinite series. You don't need to read them all. You must read the first few chapters of each book, and you can read as much as you can.
1. Probability robotics;
2. Convex optimization;
3. Linear system theory;
4. Multiple View Geometry in Computer Vision;
5. Linear estimation;
6. "Machine Learning", a book by Mr. Zhou Zhihua.
7. An Invitation to 3-D Vision;
8. Modern Control Systems;
9. Rigid Body Dynamics. To be honest, I didn't find a particularly good book on rigid body dynamics theory, but rigid body dynamics theory is very important.
10. Feedback Systems: An Introduction for Scientists and Engineers;
As I began to say, most of these books are particularly expensive, and some industry conscience authors have released an electronic version of their books. Of course, you can also go to some websites that cannot be named to find photocopies.
When reading these books, matlab and python must be at hand, and then practice the knowledge in the book. In many textbooks, some exercises that are written using matlab are included in the exercises that follow in the chapter. Try to do as many of these questions as possible.
You may have heard of ROS' name before, but it's best not to touch it before the senior year. Because ROS uses many of the underlying technologies of operating systems and networks. I have a brief introduction to knowing that “Masters can talk about some of the experiences of ROS robot operation platform development?â€. The design goal of ROS is to isolate the robot control and sensor processing software from its hardware. After using ROS, you can easily use many software codes that can be run directly. However, it takes at least one year or more for ROS to get started and mastered. You must constantly use it and constantly try new code and hardware to become familiar with it.
The ROS visualization tool Rviz uses a quaternion for the representation of the robot's rotation. When you studied the quadrotor, the code inside indicates that Euler's angle is used for rotation, and the attitude calculation may use four yuan. number. This time to start consciously to learn the differences and connections between rotating representations.
Pay attention to the internship and graduation design during the senior year. Many senior students will be very embarrassed to do a graduation project, I think it is not good. Look at the process of doing graduation design as a formal project. In addition to doing a good job in technology, this project also needs to do a good job in display. A major feature of Chinese engineers is that they do not express themselves. The level of what they can do is very high, but making PPT can cause problems with expressions such as fonts and fancy, unofficial fonts, too many words on one page, and lack of connection between graphic and text. Introducing PPT and presenting his or her own results is very important at any stage of an engineer's career. It even limits the height of what robot engineers can achieve. Only by clearly expressing their own achievements to their own team can they obtain feedback from other people and improve the overall cohesion and knowledge level of the team through communication so that they can gain more recognition in the team and contribute to the overall work efficiency of the team. The improvement. Every year, I went to several academic conferences and felt at the conference that some Chinese scientists would not be able to pay attention to their scientific research results after their speech skills were poor. Of course, researchers in other countries are also like this.
In order to write beautiful technical reports and graduation thesis, you can start learning Latex. Latex is the first writing artifact in the world, and there are many learning materials on the Internet. The learning and use of Latex also requires continuous practice and perfection. One problem with writing a dissertation is how to make beautiful vector graphics. I recommend Draw Freely | Inkscape, a freeware that is lighter than Illustrator but has more powerful features.
For those students who want to apply for study abroad, you have to show your own personal achievements and present them in the form of web pages. Bring your own Github link (if you press I said, the university will apply for a Github account on the first day, it's now a three-year old fritter), a robot video, technical reports and articles written (preferably English) placed above.
About the topic of graduation design, I recommend so few:
1. Handwritten binocular vision odometer. It involves image processing, feature matching, position solving, spatial transformation, and so on.
2. GPS-based trajectory planning for hand-written four-rotor aircraft. Involved in the deep-digging four-rotor aircraft movement principle, IMU principle, trajectory generation and optimization.
3. Create a biped servo robot that has been pushed and will not fall. Involved in servo control, inverted pendulum modeling, dynamic analysis, PID control, IMU principles.
4. Deep Learning Trains a small car to chase people. It involves the use of deep learning toolkits, data set acquisitions, data set analysis, and car control.
5. The robotic arm gives the tea water. This is relatively local tyrants, because the robotic arm that can be used directly is very expensive. It depends on the conditions of the laboratory. It involves the learning of multi-freedom robotic principle, the use of tool kits, trajectory planning and so on.
In order to do well in these projects, we must continue to invest more than three months and a certain amount of funds, each of which is more theoretical than practical. Of course, the students themselves can choose their own graduation design problems, but it is better to choose what they can run to fly, and avoid choosing to spend a lot of time to screw the screws, welding the board's problems, try to buy a ready-made motor, Development board, 3D printing structure, senior to give yourself more time to read and write code.
During the summer vacation before the senior year of graduate students, it is best to go to some of the better robot companies to intern, such as Dajiang. Of course, you can also continue to do robot competitions, such as RoboMasters and Dajiang’s aircraft competitions.
DJI engineers teach you how to become a robot engineer (I)
DJI engineers teach you how to become a robot engineer (below)
Our company specializes in the production and sales of all kinds of terminals, copper terminals, nose wire ears, cold pressed terminals, copper joints, but also according to customer requirements for customization and production, our raw materials are produced and sold by ourselves, we have their own raw materials processing plant, high purity T2 copper, quality and quantity, come to me to order it!
Cable Terminals
Taixing Longyi Terminals Co.,Ltd. , https://www.lycopperlugs.com