Design method of the hottest Cartesian coordinate

Design method of Cartesian coordinate robot

concept of Cartesian coordinate robot:

in industrial applications, it can realize automatic control, reprogrammable, multi-function, multi degree of freedom, motion degree of freedom, and build a spatial Cartesian relationship and multi-purpose operator. He can carry objects and operate tools to complete various operations. With the continuous development of science and technology, the definition of robot is constantly improving. As a kind of robot, the meaning of rectangular coordinate robot is also constantly improving

characteristics of Cartesian coordinate robot:

1. Degree of freedom motion, and the space angle between each degree of freedom is a right angle

2. Automatic control, repeatable programming, and all movements run according to the program

3. It is generally composed of control system, drive system, mechanical system, operating tools, etc

4. It is flexible and multi-functional, and its functions are different due to different operating tools

5, high reliability, high speed and high precision

6. It can be used in harsh environment, can work for a long time, and is convenient for operation and maintenance

typical Cartesian coordinate robot figure 1

application of Cartesian coordinate robot:

due to the different end operation tools, Cartesian coordinate robot can be very convenient to be used as various automation equipment to complete a series of work, such as welding, handling, loading and unloading, packaging, stacking, destacking, detection, flaw detection, classification, assembly, labeling, code spraying, code printing, (soft imitation) spraying, target following, explosive elimination and so on. It is especially suitable for flexible operations with multiple varieties and convenient batches, and plays a very important role in steadily improving product quality, improving labor productivity, improving working conditions and rapid product upgrading

application of Cartesian coordinate robots Figure 2

with the more and more extensive application of Cartesian coordinate robots, the design of Cartesian coordinate robots is becoming increasingly important. The successful design of a rectangular coordinate robot involves many aspects, including mechanical structure, power drive, servo control and so on. Shenyang Rio Tinto Automation Control Technology Co., Ltd. has many years of experience in the application of Cartesian coordinate robot technology, numerical control technology and product research and development. Relying on the linear positioning system and manipulator of Bahr company in Germany, we have developed a series of numerical control Cartesian coordinate robots with excellent price ratio, which are widely used in the production lines of automobile, electronics, electrical appliances, testing, medical treatment, aerospace, food and other fields

next, we will briefly describe the design of rectangular coordinate robot

I. robot design features:

1. Robot design is a complex work, with a large workload and a lot of knowledge involved, which often needs more than one person to complete

2. Robot design is customer-oriented, not behind closed doors. Designers need to stay with users frequently, constantly analyzing user requirements and seeking solutions

3. Robot design is a processing oriented design. No matter how good the design is, if the factory cannot process products, the design will also fail. Designers need to master a lot of processing technology and means

4. Robot design is a process of continuous improvement

2. Robot design process:

1. Analysis of use requirements: each robot is designed according to the production of specific requirements. The first step of design is to analyze the use requirements clearly and determine the parameters that need to be considered in the design, including:

positioning accuracy of robot man and repeated positioning accuracy

load size and load characteristics of the robot

the number of degrees of freedom of robot motion, and the motion stroke per degree of freedom

working cycle or moving speed, acceleration and deceleration characteristics of the robot

robot motion trajectory, action correlation

working environment and installation mode of the robot

the working system and service life of the robot

other special requirements

2. Preliminary construction of this mechanical model: the robot can be roughly divided into gantry structure, wall hanging structure and vertical hanging structure from the mechanical structure. Different structures are selected according to the requirements of installation space, and the mechanical properties and motion characteristics of each structure are different. The subsequent design must be based on a definite structure

basic structure diagram of robot III

3. Calculation of motion performance: parameters related to this performance include:

speed curve IV

average speed: v=s/t

maximum speed: vmax=at

acceleration/deceleration: a=f/m

where: s is motion stroke

t is positioning motion time

f driving force during acceleration

m moving object mass and

4 Analysis of mechanical properties

a robot is composed of many positioning units, and each positioning system needs to be analyzed. The items to be analyzed are as follows:

mechanical analysis figure V

horizontal thrust FX

positive pressure FZ

side pressure FY

MX, my, MZ

5. Mechanical strength verification:

each positioning unit and each beam should be checked. Later, they further developed a 3D printing wire brand refil with recycled plastic as raw material, especially double end support beams and cantilever beams

1) deflection deformation calculation

deflection deformation figure VI

f: load (n)

l: length of positioning unit (mm)

e: material elastic modulus

i: moment of inertia of material section (MM4)

f: deflection deformation (mm)

note: when calculating the deflection deformation, the deformation caused by the self weight of the beam cannot be ignored, and the self weight of the beam is calculated according to the uniformly distributed load

the above formula calculates the static deformation. In practical application, because the robot is always in motion, the deformation caused by the acceleration force must be calculated, and the deformation directly affects the running accuracy of the robot

2) calculation of torsional deformation:

when one end of a beam is fixed and a torque around the shaft is applied at the other end, torsional deformation will occur. In practical application, the deformation is usually caused by eccentric load or the existence of objects rotating around the axis

torsional moment analysis Figures 7 and 8

6. Drive element selection

common drive systems include: AC/tributary servo motor drive system, stepper motor drive system, linear servo motor/linear stepper motor drive system

each drive system consists of motor and driver. The function of the driver is to amplify the weak current signal and load it on the strong current of the driving motor to drive the motor. The motor converts the electrical signal into accurate speed and angular displacement

the items to be calculated are as follows:

Motor Power:

motor torque:

motor speed:

reducer reduction ratio

matching relationship between motor inertia/load inertia

please contact Shenyang Rio Tinto company for other calculation formulas and methods

7. Mechanical structure design

after completing the first six works, the prototype of a rectangular coordinate robot positioning system has been formed in the designer's mind. The next work is to draw the prototype into engineering drawings for production. We recommend users to design with 3D software to check whether there is position interference

the trajectory of the robot is uncertain and flexible. There is often no position interference in one position, but it will interfere in the next position

8. Equipment life verification

after the mechanical structure design is completed, the life of the whole equipment should be calculated, and the life of the core components should be calculated, such as the life of the robot track, the life of the reducer, the life of the servo motor, etc

the running life and speed of the robot, the size of the load, and the knot 5 Confirm that the power supply is under the specified voltage and related to the form of safety grounding structure, working environment, working system, etc

if the running life of the robot is found to be too short, the design needs to be readjusted

please contact Shenyang Rio Tinto for specific calculation methods

9. Selection of control system

robots without control system can't perform any action just as people don't have brains covering plastics, food, personal care products, medicine and medical treatment, non-woven, paint and ink, automobiles, metals, molds, packaging, composite materials, and health and anti-aging, innovative materials series forums for innovative technologies and popular markets. Therefore, we usually call the mechanical structure without control system as bare metal or robot positioning system

according to different requirements, the choice of control system is also different. Generally, the products selected as the control system are:

PLC program controller

industrial motion card

digital control system (CNC)

is specialized in controller

10. Programming

control system is the brain of robot, and program is the idea of robot. The programming directly reflects the designer's thoughts, intentions and sports needs

programming is a complex process, but as long as there is no problem with the overall design of the robot, the program will always be compiled. The following problems should be paid attention to in programming: the analysis of tasks should be clear, the programming level should be clear, and the logic should be clear

conclusion:

the design of robot is a process of continuous familiarity and improvement, which needs to be summarized and improved in practical application. The content is miscellaneous and the details are numerous. (end)