Give friends who have just contacted robots - 2003-9-4 2:21:17
Are you interested in robots? Well, that is also the only reason I built this website. But unfortunately, playing robots is not a very easy hobby, he needs more than a professional knowledge, such as machinery, electronics, computer, and you need to invest great enthusiasm, energy and money. If you don't have a strong wish to understand it, learn it, there is no certain perseverance to study it, then I advise you to give up the hobby of interested the robot as interested. Of course, if you don't miss it above, then we can continue the following. Before starting to write this article, there is a matter to declare that studying robots and research don't have something different. You can use it as a toy to study, so studying robots should be a very pleasant job, thousand Whether it takes it as a bitter thing, otherwise don't play. After decades of development, the robot has been found on foreign websites. The current robot resources are still a blank in the current robot resources. Writing this article is mainly to give some little opinions of enthusiasts who have just played robots in China. What is the robot? Since the birth of the robot has been defined in the robot, as many scholars have pointed out, many so-called robots look like robots, in fact, not real robots, such as 4 wireless remote controls Can the legs of the legs can also call robots? Of course, it is not so called. But according to my personal understanding of the robot, a so-called robot must have two most important functions. One is to communicate with the outside world, and the second is to automatically generate some reactions based on the information of the communication. This reaction can be a program written in advance, or the program produced by the robot, a sentence is to react. Of course, I haven't qualified to define robots, but on the current level of technology and the degree of understanding of robots, I think the simplest robot should have the above 2 major functions. Next is to play the robot's demand for basic knowledge, this knowledge is that people who play robots must be. Simply put, you must have high school physics knowledge, and also know the role of capacitance, inductance, the role of the diode, the working principle of the DC motor, the use of the light-emitting diode, the use of transformers, if you have learned a university analog circuit and The digital circuit plus the principle of electrician, then your electronic theory knowledge is basically enough, and the rest is practical. To be honest, the basis of the mechanical part is basically no need. As long as there is a point of mechanical common sense, I believe that the friends who play the robot have not been dismantled, pay more attention to the mechanical structure, there is no big problem. Of course, if you want to learn how to design a robot such as 2 legs, or other legs, you need a little bit of mechanical principles in the university, but don't worry, as long as you don't involve what fatigue strength, load school This part of the test, other parts are very easy to understand. But if you just do a simplest wheel robot, then these content can be saved. Finally, the robot's soul, programming, no matter how, you will be a so-called robot, you must write procedures, this is the most basic, because the current market situation, you can easily buy electrons and Mechanical kit, but you can absolutely can't buy robotics, if you can buy it, if you don't write a program, you can't improve it, this robot is not your child in strict sense, just like your parents, But give you thinking, and raise your people more important to you.
Don't be afraid of trouble, truthful procedures are not a difficult thing, generally spend a few weeks at night to see some simple programming, such as C, just learn one, then learn other programming languages Easy. So I must calm down, seriously learn a door, this time, the driving force is to be the unparalleled robot. These knowledge is best to play while learning. When I learned the machine, I started designing robotic sites. When I learned electronics, I designed robotic circuits, and I started writing robotic procedures. Otherwise, I believe that there are not many people to support it. Of course, you can also jump out of the mechanical part to purchase finished products, which can directly use current mature and relatively more products.
Let's introduce a physical component of a robot "toy": robot's brain: it can have a lot of call, can be called microcontroller, microprocessor, processor or calculator, etc., but this is not tight, usually micro The processor refers to a piece of chip, while others are a set of controllers, including microprocessors and some other components. Any robot must have this chip, otherwise it is not the robot. If you are a beginner, or if you start playing robots, it is best to buy a controller to play, don't play microprocessors, unless you graduate from your electronic, and professional is chip design, then you can Into the microprocessor (huh, let's make a joke, but the microprocessor is more difficult to say to beginners, or by simple. When selecting a microcontroller, it is mainly considered: the speed of the processor, the size of the ROM, and RAM, I / O port type, and quantity, programming language, and power consumption.
When purchasing a microcontroller, one of the most considered is the speed, the main indicator is running speed MHz, the evaluation index of this computer is the same, the higher MHZ means, the faster, the speed, the more you pay more. Money. This second storage capacity indicator is to determine how much and complexity of your controller can implement, the more storage space allows you to store more program code to achieve more, more complex features. The number of I / O interfaces and the number of interfaces refers to the number of interfaces. There are two types of interface types, Analog (analogs), and Digital interfaces. This interface species determines that your controller can control hardware types. If your motor control card is a digital interface, then your controller must have a digital output interface. If your sensor is an analog interface, then your controller must have an analog input interface. The number of interfaces refers to how much it can be connected at the same time. The programming language is a language type that can be accepted by a controller. There are generally C language, assembly language or Basic language. These are usually performed directly by the advanced controller, because in the high-level controller, the compiler can directly put some advanced Language translation into machine code, but now almost every controller supports C language, if you will C language, the programmed problem is very small, if you won't want to learn, then you have to spend some Time to find a corresponding compiler to compile the advanced languages you write into the execution code you select the controller. Therefore, it is recommended that people who want to play robots learn a little C, after all, this is the language currently accepted by most compilers or controllers. The last thing to consider is how to consider power consumption, because the robot is not very good to drag a long power cord on your ass, in addition to considering the power consumption of the motor, another power consumption is the controller. . When considering this parameter, mainly consider what your power supply is, the robot is expected to run. However, this problem is not very big for us, unless you do that small robot, or now the power consumption of the controller is not very big, so a little bigger robot will have enough power supply.
Sensor is the link between the robot and the real world. However, as far as current sensor technology, the sensor we can use now or the burden is not much. According to the work characteristics of the sensor, it can be divided into, optical sensors, as the name implies are sensors, such as infrared sensors, acoustic sensors, such as microPhone, force sensors, such as spheric sensors, such as a gyroscope. Light sensor: The light sensor has a wide range, and the simplest photosensitive resistor is the size of the light intensity changes the resistance of the resistance to realize the perception of light intensity, and there is currently the most complex camera Camera. However, in our robot, the most used is the INFRA-RED infrared sensor, where the infrared proximity sensor is an essential sensor in the process of motion, through which we can get the robot's in the movement process with front obstacles The distance between things, of course, this distance is very short. However, for our robots, this is also the only unique choice. There is also a relatively useful infrared sensor called an infrared detector, which is different from the infrared proximity sensor above, which does not have an infrared transmitter, only an infrared acceptance unit, which is infrared by the object. It is generally used to do thermal applications, such as people approach or animals into such sensors, it will generate signals. There are more in the field of production safety. For us, the most is that someone can enter it as a perceptual means to get the robot: "Wow, there is an infrared guy rushing me over". " Infrared Sensor
There is also a kind of camera that we can also withstand. With the rapid development of computer technology, today I get a cheap camera is already very easy. A ordinary camera is currently selling in the market. RMB200 more points. However, for us, it is supported, which can be applied to robotic identification software and hardware is relatively small and expensive. The current mature market products have CMU-Camera sets developed by the US Carnegie-Mellon University, but to 100 US dollar, almost 850RMB, relatively price is still a little higher. But if we don't have to use their suit, other hardware investments are relatively small, but you have to be quite proficient in computer programming, and difficult is relatively large. A simple image identification software is less than a computer professional graduation undergraduate 4-5 month working hours to write. Don't say some software that makes more functions. However, as the current research is in full swing in the world, it is believed that there will be many products available in the next 2 years. Force Sensor: The force sensor is used to detect collisions or contact signals, such as robot applications. When you put a thing to the robot, the robot automatically grabs it, it requires force sensor to detect things. A typical force sensor is a micro switch and a pressure sensitive sensor. The micro switch is actually a small switch. By adjusting the lever on the switch, the size of the force of the truck switch can be adjusted. It is best to use to do collision. However, this sensor must determine the powerful threshold in advance, that is, hardware control can only be achieved. The pressure sensitive sensor can automatically adjust the output voltage or current according to the size of the force, so that software control can be implemented. Sound sensor: Haha, this part I don't have to introduce, the most is the microphone. A few dollars, the world is all. But now the only problem is how to handle sound signals. There is no more good sound solution, there are currently several products in foreign countries, but you can't identify Chinese, all in English. I don't know if the ultrasonic sensor belongs to this category, ultrasonic sensors and infrared proximity sensors are very similar, and they are also a distance detecting sensor, but it provides a range of detection than infrared sensors, but also provides a range of probes rather than a line. Detection. It is also one of the most range of distance sensors we use. Location and posture sensors: Robots must always know their attitude action while moving or movement, otherwise one open problem in control is generated, without feedback. The position sensor and posture sensor are used. Commonly used photoelectric encoders, since the actuator's actuator is typically driven, by calculating the number of turns of the motor, the substantially position of the motor driven, the encoder is such a sensor, which is generally and the motor shaft or rotation The component is directly connected, the motor or the rotating member rotates, or the angle can be read by the encoder, and the control software is estimated according to the read data. There is also a gyroscope, which is a sensor made of gyro principle, mainly to measure the mobile acceleration, turning angle, etc. of mobile robots. Relevant principles should refer to the relevant content of the university physics. The difficulty is slightly larger. And the current price is also more expensive. The compass is a replacement of the gyroscope for us. It uses the principle of the compass to measure the perspective of the robot, the price is much cheaper than the gyroscope. About 150RMB left and right. The last one is to introduce the GPS positioner. For the outdoor mobile robots, this is a must-have means. It takes a satellite to locate your robot, listen to very high technology, so the price is very high. A GPS positioning module is currently priced about 1500RMB.
Summary Summary: Of course, the above is just part of the sensor, and many sensors have not been discussed, such as the popular laser range detector, this sensor can provide 50m detection range, and infrared approaching sensors can only provide 50cm, The ultrasonic sensor can provide 10m. As the detection distance increases, the price is also improved in geometric grade, such a laser sensor usually requires 2W RMB, definitely not we can afford it, and there is no miniaturization, one is about 2kg . These sensors are currently not available because of such or such reasons. Drive: The drive is a component that drives the robot. The most commonly used motors. Of course, there is also hydraulic, pneumatic and other drive methods, but due to control, the price is higher, it is not suitable for us. The most important amount of robot is to control the movement of the robot. Whether it is the movement of the joints of the arm, the most fundamental and essential problem in the robot driver is to control the motor, control the number of turns of the motor, and control the robot. The distance and direction of the movement, the degree of bending of the robot arm or the distance of moving. Therefore, the first question to solve is how to make the motor rotate according to your intentions. In general, there is a special control card and control chip to control. With these control cards and chips, what we have to do is to connect the microcontroller and these, then you can use the program to control the motor. The second problem is to control the speed of the motor, the actual performance on the robot is the actual movement of the robot or arm, and the robot is slowly slow-relying on the speed of the motor, so we ask the control card to have speed control of the motor. There are two types of motor (Stepper motor) and DC Motor. DC motor. The most common motor is the most common electric toy, the DC motor, the biggest problem of DC motor. It is not possible to accurately control the number of turns of the motor turn, which is also controlled by the previous position. You have to add an encoding disk to feedback to get the number of turns of the actual turn. At this time, the DC motor becomes a servo motor. However, the speed control of the DC motor is relatively simple, and the motor speed can be easily adjusted with a speed control method called PWM. There are also a lot of control chip tape speed. The parameters to be considered when purchasing are the output torque of the motor, the power of the motor, the highest speed of the motor.
RC Servo Motor
Stepper motor stepper motor will look at the name, it is a step forward. That is, it can rotate one angle, not like a DC motor, you can easily adjust the position of the stepper motor, if you send a 10-turn directive, the stepper motor will not turn 11 laps, but If it is a DC motor, it may turn 11 turns for half a circle due to inertia. As for why there is such a difference, it is recommended to see the principle of the relevant motor. The speed of the stepper motor is obtained by controlling the frequency of the motor. The higher the frequency of control signals, the faster the motor is transferred, the lower the frequency, the slower the turn. The parameters to be considered when purchasing are the output torque of the motor, the power of the motor, the minimum angle of each pulse motor. Under normal circumstances, the motor can not directly drive the wheel or arm, because the torque is not large enough, so we need to add a gearbox to increase the output torque of the motor, but the cost is reduced by the motor speed, such as a 1: 250 gear. The box will make the output torque of your motor by 250 times, but the speed is only 1/250. First calculate the torque size required by the robot, then select the motor according to the torque.
Stepper Motor
