拆开KUKA机器人，解析工业机器人的内部结构！
一、机器人驱动装置
概念：要使机器人运行起来, 需给各个关节即每个运动自由度安置传动装置 作用：提供机器人各部位、各关节动作的原动力。
驱动系统：可以是液压传动、气动传动、电动传动, 或者把它们结合起来应用的综合系统; 可以是直接驱动或者是通过同步带、链条、轮系、谐波齿轮等机械传动机构进行间接驱动。
1、电动驱动装置
电动驱动装置的能源简单，速度变化范围大，效率高，速度和位置精度都很高。但它们多与减速装置相联，直接驱动比较困难。
电动驱动装置又可分为直流(DC)、交流(AC)伺服电机驱动和步进电机驱动。直流伺服电机电刷易磨损，且易形成火花。无刷直流电机也得到了越来越广泛的应用。步进电机驱动多为开环控制，控制简单但功率不大，多用于低精度小功率机器人系统。
电动上电运行前要作如下检查：
1）电源电压是否合适（过压很可能造成驱动模块的损坏）；对于直流输入的+/-极性一定不能接错，驱动控制器上的电机型号或电流设定值是否合适（开始时不要太大）；
2）控制信号线接牢靠，工业现场最好要考虑屏蔽问题（如采用双绞线）；
3）不要开始时就把需要接的线全接上，只连成最基本的系统，运行良好后，再逐步连接。
4）一定要搞清楚接地方法，还是采用浮空不接。
5）开始运行的半小时内要密切观察电机的状态，如运动是否正常，声音和温升情况，发现问题立即停机调整。
2、液压驱动
通过高精度的缸体和活塞来完成，通过缸体和活塞杆的相对运动实现直线运动。
优点：功率大，可省去减速装置直接与被驱动的杆件相连，结构紧凑，刚度好，响应快，伺服驱动具有较高的精度。
缺点：需要增设液压源，易产生液体泄漏，不适合高、低温场合，故液压驱动目前多用于特大功率的机器人系统。
选择适合的液压油。防止固体杂质混入液压系统，防止空气和水入侵液压系统 。机械作业要柔和平顺机械作业应避免粗暴，否则必然产生冲击负荷，使机械故障频发，大大缩短使用寿命。要注意气蚀和溢流噪声。作业中要时刻注意液压泵和溢流阀的声音，如果液压泵出现“气蚀”噪声，经排气后不能消除，应查明原因排除故障后才能使用。保持适宜的油温。液压系统的工作温度一般控制在30～80℃之间为宜。
3、气压驱动
气压驱动的结构简单，清洁，动作灵敏，具有缓冲作用。.但与液压驱动装置相比，功率较小，刚度差，噪音大，速度不易控制，所以多用于精度不高的点位控制机器人。
（1）具有速度快、系统结构简单，维修方便、价格低等特点。适于在中、小负荷的机器人中采用。但因难于实现伺服控制，多用于程序控制的机械人中，如在上、下料和冲压机器人中应用较多。
（2）在多数情况下是用于实现两位式的或有限点位控制的中、小机器人中的。
（3）控制装置目前多数选用可编程控制器(PLC控制器)。在易燃、易爆场合下可采用气动逻辑元件组成控制装置。
二、直线传动机构
传动装置是连接动力源和运动连杆的关键部分，根据关节形式，常用的传动机构形式有直线传动和旋转传动机构。
直线传动方式可用于直角坐标机器人的X、Y、Z向驱动，圆柱坐标结构的径向驱动和垂直升降驱动，以及球坐标结构的径向伸缩驱动。
直线运动可以通过齿轮齿条、丝杠螺母等传动元件将旋转运动转换成直线运动，也可以有直线驱动电机驱动，也可以直接由气缸或液压缸的活塞产生。
1、齿轮齿条装置
通常齿条是固定的。齿轮的旋转运动转换成托板的直线运动。
优点：结构简单。
缺点：回差较大。
2、滚珠丝杠
在丝杠和螺母的螺旋槽内嵌入滚珠，并通过螺母中的导向槽使滚珠能连续循环。
优点：摩擦力小，传动效率高，无爬行，精度高
缺点：制造成本高，结构复杂。
自锁问题：理论上滚珠丝杠副也可以自锁,但是实际应用上没有使用这个自锁的,原因主要是：可靠性很差，或加工成本很高；因为直径与导程比非常大，一般都是再加一套蜗轮蜗杆之类的自锁装置。
三、旋转传动机构
采用旋转传动机构的目的是将电机的驱动源输出的较高转速转换成较低转速，并获得较大的力矩。机器人中应用较多的旋转传动机构有齿轮链、同步皮带和谐波齿轮。
1、齿轮链
（1）转速关系
（2）力矩关系
2、同步皮带
同步带是具有许多型齿的皮带，它与同样具有型齿的同步皮带轮相啮合。工作时相当于柔软的齿轮。
优点：无滑动，柔性好，价格便宜，重复定位精度高。
缺点：具有一定的弹性变形。
3、谐波齿轮
谐波齿轮由刚性齿轮、谐波发生器和柔性齿轮三个主要零件组成，一般刚性齿轮固定，谐波发生器驱动柔性齿轮旋转。
主要特点：
(1)、传动比大，单级为50—300。
(2)、传动平稳，承载能力高。
(3)、传动效率高,可达70%—90%。
(4)、传动精度高,比普通齿轮传动高3—4倍。
(5)、回差小，可小于3’。
(6)、不能获得中间输出，柔轮刚度较低。
谐波传动装置在机器人技术比较先进的国家已得到了广泛的应用。仅就日本来说，机器人驱动装置的60％都采用了谐波传动。
美国送到月球上的机器人，其各个关节部位都采用谐波传动装置，其中一只上臂就用了30个谐波传动机构。
前苏联送入月球的移动式机器人“登月者”，其成对安装的8个轮子均是用密闭谐波传动机构单独驱动的。德国大众汽车公司研制的ROHREN、GEROT R30型机器人和法国雷诺公司研制的VERTICAL 80型机器人等都采用了谐波传动机构。
四、机器人传感系统
1、感受系统由内部传感器模块和外部传感器模块组成, 用以获取内部和外部环境状态中有意义的信息。
2、智能传感器的使用提高了机器人的机动性、适应性和智能化的水准。
3、智能传感器的使用提高了机器人的机动性、适应性和智能化的水准。
4、对于一些特殊的信息, 传感器比人类的感受系统更有效。
五、机器人位置检测
旋转光学编码器是最常用的位置反馈装置。光电探测器把光脉冲转化成二进制波形。轴的转角通过计算脉冲数得到，转动方向由两个方波信号的相对相位决定。
感应同步器输出两个模拟信号——轴转角的正弦信号和余弦信号。轴的转角由这两个信号的相对幅值计算得到。感应同步器一般比编码器可靠，但它的分辨率较低。
电位计是最直接的位置检测形式。它连接在电桥中，能够产生与轴转角成正比的电压信号。但是，由于分辨率低、线性不好以及对噪声敏感。
转速计能够输出与轴的转速成正比的模拟信号。如果没有这样的速度传感器，可以通过对检测到的位置相对于时间的差分得到速度反馈信号。
六、机器人力检测
力传感器通常安装在操作臂下述三个位置：
1、安装在关节驱动器上。可测量驱动器/减速器自身的力矩或者力的输出。但不能很好地检测末端执行器与环境之间的接触力。
2、安装在末端执行器与操作臂的终端关节之间，可称腕力传感器。通常，可以测量施加于末端执行器上的三个到六个力/力矩分量。
3、安装在末端执行器的“指尖”上。通常，这些带有力觉得手指内置了应变计，可以测量作用在指尖上的一个到四个分力。
七、机器人－环境交互系统
1、机器人-环境交互系统是实现工业机器人与外部环境中的设备相互联系和协调的系统。
2、工业机器人与外部设备集成为一个功能单元，如加工制造单元、焊接单元、装配单元等。也可以是多台机器人、多台机床或设备、多个零件存储装置等集成 。
3、也可以是多台机器人、多台机床或设备、多个零件存储装置等集成为一个去执行复杂任务的功能单元。
八、人机交互系统
人机交互系统是使操作人员参与机器人控制并与机器人进行联系的装置。该系统归纳起来分为两大类: 指令给定装置和信息显示装置。

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英文版：

Unpack the KUKA robot and analyze the internal structure of the industrial robot!
First, the robot drive device
Concept: In order to make the robot run, it is necessary to place the transmissions for each joint, that is, for each degree of freedom of movement: to provide the motive force for the movement of various parts of the robot and each joint.
Drive system: It can be hydraulic drive, pneumatic drive, electric drive, or a combination of them; it can be directly driven or indirectly driven by mechanical transmission mechanisms such as timing belts, chains, trains, harmonic gears.
1. Electric drive device
The electric drive unit has a simple energy source, a wide range of speed changes, high efficiency, and high speed and position accuracy. However, they are often associated with a reduction gear, and direct drive is more difficult.
The electric drive can be divided into direct current (DC), alternating current (AC) servo motor drive and stepper motor drive. DC servo motor brushes are prone to wear and are prone to sparks. Brushless DC motors have also become more widely used. The stepper motor drive is mostly open-loop control, the control is simple but the power is not large, and it is mostly used in low-precision low-power robot systems.
Check the following before electric power-on:
1) Is the power supply voltage suitable (overvoltage is likely to cause damage to the drive module); the +/- polarity of the DC input must not be connected incorrectly, and the motor model or current setting value on the drive controller is appropriate (do not start at the beginning) Too big);
2) The control signal line is firmly connected, and the industrial site should preferably consider the shielding problem (such as using twisted pair);
3) Do not connect the wires that need to be connected when starting. Only connect to the most basic system. After running well, connect them step by step.
4) Be sure to find out the grounding method, or use the floating.
5) Closely observe the state of the motor within half an hour of starting operation, such as whether the motion is normal, sound and temperature rise, and immediately stop the adjustment after finding the problem.
2, hydraulic drive
This is done by a high-precision cylinder and piston, which is linearly moved by the relative movement of the cylinder and the piston rod.
Advantages: The power is large, and the speed reducing device can be directly connected with the driven rod member, the structure is compact, the rigidity is good, the response is fast, and the servo drive has high precision.
Disadvantages: It is necessary to add a hydraulic source, which is prone to liquid leakage, and is not suitable for high and low temperature applications. Therefore, hydraulic drive is currently used for robot systems with extra high power.
Choose the right hydraulic fluid. Prevent solid impurities from mixing into the hydraulic system and prevent air and water from invading the hydraulic system. The mechanical operation should be gentle and smooth. The mechanical operation should avoid roughness, otherwise the impact load will be generated, causing frequent mechanical failures and greatly shortening the service life. Pay attention to cavitation and overflow noise. Always pay attention to the sound of the hydraulic pump and the relief valve during the operation. If the hydraulic pump has “cavitation” noise, it cannot be eliminated after exhausting. It should be found that the cause can be used after troubleshooting. Maintain a suitable oil temperature. The working temperature of the hydraulic system is generally controlled between 30 and 80 °C.
3, pneumatic drive
The air-driven structure is simple, clean, sensitive, and has a cushioning effect. However, compared with the hydraulic drive device, the power is small, the rigidity is poor, the noise is large, and the speed is not easy to control, so it is often used for a point-controlled robot with low precision.
(1) It has the characteristics of fast speed, simple system structure, convenient maintenance and low price. Suitable for use in medium and small load robots. However, it is difficult to implement servo control, and many of them are used in program control, such as upper and lower materials and punching robots.
(2) In most cases, it is used in medium and small robots that implement two-bit or finite point control.
(3) Most of the control devices currently use programmable controllers (PLC controllers). In flammable and explosive situations, pneumatic logic components can be used to form the control device.
Second, linear transmission mechanism
The transmission is a key part of the connection between the power source and the moving link. According to the joint form, the commonly used transmission mechanism has a linear transmission and a rotary transmission mechanism.
The linear transmission mode can be used for X, Y, Z direction driving of Cartesian robots, radial driving and vertical lifting driving of cylindrical coordinate structures, and radial stretching driving of spherical coordinate structures.
The linear motion can convert the rotary motion into a linear motion through a transmission component such as a rack and pinion, a screw nut, or the like, or can be driven by a linear drive motor or directly by a piston of a cylinder or a hydraulic cylinder.
1, rack and pinion device
Usually the rack is fixed. The rotational motion of the gear is converted into a linear motion of the pallet.
Advantages: Simple structure.
Disadvantages: The difference is large.
2, ball screw
The ball is embedded in the spiral groove of the lead screw and the nut, and the ball can be continuously circulated through the guide groove in the nut.
Advantages: low friction, high transmission efficiency, no creep, high precision
Disadvantages: high manufacturing costs and complex structure.
Self-locking problem: In theory, the ball screw pair can also be self-locking, but the self-locking is not used in practical applications, mainly because of poor reliability or high processing cost; because the diameter to lead ratio is very large, Generally, a self-locking device such as a worm gear is added.
Third, the rotating transmission mechanism
The purpose of the rotary transmission mechanism is to convert the higher rotational speed of the motor's drive source output to a lower rotational speed and obtain a larger torque. Rotary transmission mechanisms that are used more in robots include gear chains, timing belts, and harmonic gears.
1, the gear chain
(1) Speed relationship
(2) Torque relationship
2, timing belt
The timing belt is a belt having a plurality of teeth that mesh with a timing pulley that also has a tooth. It is equivalent to a soft gear when working.
Advantages: no sliding, good flexibility, low price, high repeatability.
Disadvantages: There is a certain elastic deformation.
3, harmonic gear
The harmonic gear is composed of three main parts: a rigid gear, a harmonic generator and a flexible gear. Generally, the rigid gear is fixed, and the harmonic generator drives the flexible gear to rotate.
main feature: 
(1) The transmission ratio is large, and the single stage is 50-300.
(2) The transmission is stable and the carrying capacity is high.
(3), transmission efficiency is high, up to 70% -90%.
(4) High transmission precision, 3-4 times higher than ordinary gear transmission.
(5), the difference is small, can be less than 3'.
(6), the intermediate output cannot be obtained, and the flexural rigidity is low.
Harmonic transmissions have been widely used in countries with advanced robotics. In Japan alone, 60% of robotic drives use harmonic drives.
The robots sent to the moon by the United States use harmonic transmissions for each joint, and one of the upper arms uses 30 harmonic transmission mechanisms.
The mobile robot "moon stalker" sent to the moon by the former Soviet Union, the eight wheels installed in pairs are individually driven by a closed harmonic drive mechanism. The ROHREN, GEROT R30 robot developed by Volkswagen AG and the VERTICAL 80 robot developed by Renault of France all adopt harmonic drive mechanism.
Fourth, the robot sensing system
1. The sensing system consists of an internal sensor module and an external sensor module to obtain meaningful information in the internal and external environmental conditions.
2. The use of smart sensors improves the maneuverability, adaptability and intelligence of the robot.
3. The use of smart sensors improves the maneuverability, adaptability and intelligence of the robot.
4. For some special information, the sensor is more effective than the human perception system.
Five, robot position detection
Rotating optical encoders are the most commonly used position feedback devices. Photodetectors convert light pulses into binary waveforms. The rotation angle of the shaft is obtained by calculating the number of pulses, and the direction of rotation is determined by the relative phases of the two square wave signals.
The inductive synchronizer outputs two analog signals, the sine and cosine signals of the shaft angle. The corner of the shaft is calculated from the relative amplitudes of the two signals. Inductive synchronizers are generally more reliable than encoders, but have lower resolution.
Potentiometers are the most direct form of position detection. It is connected to the bridge and produces a voltage signal proportional to the angle of the shaft. However, due to low resolution, poor linearity, and sensitivity to noise.
The tachometer can output an analog signal proportional to the speed of the shaft. If there is no such speed sensor, the speed feedback signal can be obtained by the difference of the detected position with respect to time.
Sixth, robot force detection
The force sensor is usually mounted in the following three positions on the operating arm:
1. Install on the joint drive. The torque or force output of the drive/gearbox itself can be measured. However, the contact force between the end effector and the environment cannot be well detected.
2. It is installed between the end effector and the terminal joint of the operating arm and can be called the wrist force sensor. Typically, three to six force/torque components applied to the end effector can be measured.
3. Install on the “fingertip” of the end effector. Often, these forces feel that a strain gauge is built into the finger to measure one to four component forces acting on the fingertip.
Seven, robot-environment interaction system
1. The robot-environment interaction system is a system that enables industrial robots to communicate and coordinate with devices in the external environment.
2. The industrial robot is integrated with external equipment as a functional unit, such as a manufacturing unit, a welding unit, an assembly unit, and the like. It can also be integrated with multiple robots, multiple machine tools or equipment, multiple parts storage devices, and more.
3. It can also be a multi-robot, multiple machine tools or equipment, multiple parts storage devices, etc. integrated into one functional unit to perform complex tasks.
Eight, human-computer interaction system
The human-computer interaction system is a device that allows an operator to participate in robot control and to communicate with the robot. The system is grouped into two broad categories: command given devices and information display devices.
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