1.1 Background
This is a corporation project with an industrial company, Mingji Electronics Technology Group, to design and fabricate a multi-axis material transportation robot. In order to improve the manufacturing efficiency, reliability, product quality and provide a health-working environment for the workers. The major requirements of our customer are:
In recent global market, there are plenty of multi-axis robot could fulfill the requirements, however, the price are extremely expensive when compare with a three axis machine. The saleing prcie of a high precision multi-axis robot is around HKD$180000, while the estimated cost of fabricating a three axis machine is about HKD$30000. Besides, after visiting the factory of our customer, we confirmed that the high precision multi-axis robot is not suitable for our client. First, the production line is in longitudinal direction, translation of cable holding device should assist by other machine. Second, the range of activities of a multi-axis robot is small, there should be three or more numbers of multi-axis robot to complete the work in one production line. Third, the production flow of multi-axis robot is incompact, each robot could only hold one cable holding device in one time.
Regarding the existing machines (figure 2) in client’s factory, the platfroms for cable holding device are perfectly fit the size of cable holding device. Due to the fact, our customer requires the machine to be high pricision. Moreover, our machine’s width should not be too wide as to maintain the aisle for workers.
Base on several objective factors, we prefer using the pneumatic products from SMC. On aspect of repairing, the SMC products are commonly have one year warranty, if any part of our machine was damage, we can have assistance from SMC. Moreover, SMC’s products are widely used in automation industry, our client may find the original model or similar model for maintenance easily. On aspect of cost, using pneumatic products is the most economic way to build a multi-axis machine. The price of pneumatic products could be three times lower than the electrical products, bisides, pneumatic cylinders are already one of the tools in our client’s factory. On aspect of manufacturing, uniting the types of material could reduce time consuming on studying new product. If we choose electrical cylinder in one of the axises, the PLC programme would include both solenoid valves and encoders, that would be more complicated in control programme design which is also inconvenient to users.
1.2 Objective
Our design had considered five aspects yet in weighted, 7 presents in appearance, 35 percents in applicability, 28 percents in cost, 14 percents in ease of manufacturing and 16 presents in maintenance. This proportion can extend to our design objective, our product should be practical, efficient, user friendly and economic.
As combined the customer requirements, market situation and existing constraints, several solution has been formed. To attain the requirement of 0.05mm tolerance, we decided to add a stopper at the position of existing machine, in order to the guide the pneumatic cylinder stop at exact position precisely. On the other hand, a pair of transitional machine in x-axis direction was used instead of using only one. This design could improve the efficiency of whole system by allowing two cable holding device working on the same time, which means the working process could overlap, reducing the waiting time of existing machines. Furthermore, after estimating the movement of rotational gripper (0 - 90 degree), we decided to separate it into two parts, rotational cylinder and gripper. Base on the reason of gas pipe would twine with the cable and y-axis cylinder.
As our group is corporate with mainland company, the product should finally separate into small components and deliver to customer’s factory. Although the appearance of our product looks bulky, it could break down into several parts tidily. Therefore, in the design stage, we try to avoid using large components and parts would permanently mate.
1.3 Design Statement
There are few major deliverable of the project:
The first day (19th Jan. 2016) of visiting customer’s factory in Dong Guan was important, as we familiarize the situations of this project. Such as the requirement and expectation of our client in detail, the environment of the factory, the detail dimension of the workpiece and the manufacturing flow of the cables.
In the second visit to the factory on 22nd Mar. 2016, we introduced the preliminary design to our client and confirmed some detail dimensions such as distances between existing machines and their specific dimensions. Our client had some commend to the design and they confirmed to use SMC’s products and some electrical devices from Wah Fai.
On 21st Apr. 2016, the completion in design stage, all materials were chosen and ready to deliver from suppliers.
On 16th May. 2016, most of the materials arrived, the manufacturing stage could start immediately.
Some technical requirements and considerations were raised by Mingji’s engineer:
This project consist some development constraints. Such as there is a budget that we cannot get over it so that the selection of materials or cylinders should not be too expensive. Also, the timing control is another important issue that the workpiece should be finished the whole process within a short time. Besides, due to the limited place for placing the machine system and the working platform, the positioning should be well planned. In addition, we should also consider the durability of the machine.
This is a corporation project with an industrial company, Mingji Electronics Technology Group, to design and fabricate a multi-axis material transportation robot. In order to improve the manufacturing efficiency, reliability, product quality and provide a health-working environment for the workers. The major requirements of our customer are:
- The robot should be compact and reliable
- The traveling strokes of X, Y and Z axis are about 500mm, 300mm and 100mm respectively
- The gripper can be used to handle and rotate (0‐180 degree)
- The cable holding device (figure 1) can be transferred from one station to the other station
- The tolerance would be 0.05mm
In recent global market, there are plenty of multi-axis robot could fulfill the requirements, however, the price are extremely expensive when compare with a three axis machine. The saleing prcie of a high precision multi-axis robot is around HKD$180000, while the estimated cost of fabricating a three axis machine is about HKD$30000. Besides, after visiting the factory of our customer, we confirmed that the high precision multi-axis robot is not suitable for our client. First, the production line is in longitudinal direction, translation of cable holding device should assist by other machine. Second, the range of activities of a multi-axis robot is small, there should be three or more numbers of multi-axis robot to complete the work in one production line. Third, the production flow of multi-axis robot is incompact, each robot could only hold one cable holding device in one time.
Regarding the existing machines (figure 2) in client’s factory, the platfroms for cable holding device are perfectly fit the size of cable holding device. Due to the fact, our customer requires the machine to be high pricision. Moreover, our machine’s width should not be too wide as to maintain the aisle for workers.
Base on several objective factors, we prefer using the pneumatic products from SMC. On aspect of repairing, the SMC products are commonly have one year warranty, if any part of our machine was damage, we can have assistance from SMC. Moreover, SMC’s products are widely used in automation industry, our client may find the original model or similar model for maintenance easily. On aspect of cost, using pneumatic products is the most economic way to build a multi-axis machine. The price of pneumatic products could be three times lower than the electrical products, bisides, pneumatic cylinders are already one of the tools in our client’s factory. On aspect of manufacturing, uniting the types of material could reduce time consuming on studying new product. If we choose electrical cylinder in one of the axises, the PLC programme would include both solenoid valves and encoders, that would be more complicated in control programme design which is also inconvenient to users.
1.2 Objective
Our design had considered five aspects yet in weighted, 7 presents in appearance, 35 percents in applicability, 28 percents in cost, 14 percents in ease of manufacturing and 16 presents in maintenance. This proportion can extend to our design objective, our product should be practical, efficient, user friendly and economic.
As combined the customer requirements, market situation and existing constraints, several solution has been formed. To attain the requirement of 0.05mm tolerance, we decided to add a stopper at the position of existing machine, in order to the guide the pneumatic cylinder stop at exact position precisely. On the other hand, a pair of transitional machine in x-axis direction was used instead of using only one. This design could improve the efficiency of whole system by allowing two cable holding device working on the same time, which means the working process could overlap, reducing the waiting time of existing machines. Furthermore, after estimating the movement of rotational gripper (0 - 90 degree), we decided to separate it into two parts, rotational cylinder and gripper. Base on the reason of gas pipe would twine with the cable and y-axis cylinder.
As our group is corporate with mainland company, the product should finally separate into small components and deliver to customer’s factory. Although the appearance of our product looks bulky, it could break down into several parts tidily. Therefore, in the design stage, we try to avoid using large components and parts would permanently mate.
1.3 Design Statement
There are few major deliverable of the project:
- The robot arm can hold the workpiece tightly.
- The robot arm can deliver the workpiece to each station for its working.
- The workpiece will not drop when robot arm is passing it to the other arm.
- The robot machine system can finish the whole process in a short time.
- The robot must be safe to the users.
- The price may be under HKD 30,000 (budget)
The first day (19th Jan. 2016) of visiting customer’s factory in Dong Guan was important, as we familiarize the situations of this project. Such as the requirement and expectation of our client in detail, the environment of the factory, the detail dimension of the workpiece and the manufacturing flow of the cables.
In the second visit to the factory on 22nd Mar. 2016, we introduced the preliminary design to our client and confirmed some detail dimensions such as distances between existing machines and their specific dimensions. Our client had some commend to the design and they confirmed to use SMC’s products and some electrical devices from Wah Fai.
On 21st Apr. 2016, the completion in design stage, all materials were chosen and ready to deliver from suppliers.
On 16th May. 2016, most of the materials arrived, the manufacturing stage could start immediately.
Some technical requirements and considerations were raised by Mingji’s engineer:
- The minimum safety factor is 2.
- The tolerance is 0.05mm.
- The PLC may retain some input and output ports for future development
- The bending moment on the supporting frame should be avoid
- The oscillation due to movement of cylinders should be avoid
- The speed of cylinders is 100mm/s
- The compatibility of machine to existing system
This project consist some development constraints. Such as there is a budget that we cannot get over it so that the selection of materials or cylinders should not be too expensive. Also, the timing control is another important issue that the workpiece should be finished the whole process within a short time. Besides, due to the limited place for placing the machine system and the working platform, the positioning should be well planned. In addition, we should also consider the durability of the machine.