Automated Wall Painting Robots Information Technology Essay
Automation is the use of machines, control systems and information technologies to improve productivity in the production of goods and delivery of services. The appropriate reason for applying automation is to boost up productivity and quality beyond that possible with current human labor levels so as to realize economies of scale, and realize predictable quality levels. The inappropriate application of automation, which arises most often, is a tendency to eliminate or replace human labor. Simply because, correct application of automation can net as much as 3 to 4 times original output with no increase in current human labor costs whereas incorrect application of automation can only save a fraction of current labor level costs. In the room of industrialization, automation is a phase beyond mechanization as the latter provides human operators with machinery to help them with the muscular requirements of work whereas automation greatly reduces the need for human sensory and mental requirements and on the same time rising load capacity, speed, and repeatability. Automation is becoming an increasingly important aspect in the world economy and in daily experience. [1]
Automation has had a remarkable impact in a wide range of industries beyond manufacturing. Automated telephone switchboards and answering machines have nowadays substituted once-ubiquitous telephone operators. Medical practices, for instance, primary screening in electrocardiography or radiography and laboratory analysis of human genes, sera, cells, and tissues are processed at much higher speed and accuracy by automated systems. Automated teller machines have decreased the need for people to queue up in banks to obtain cash or carry out transactions. In general, automation has been responsible for the shift in the world economy from industrial jobs to service jobs in the 20th and 21st centuries. [2]
In recent years, the construction industry has experienced the effects of an aging work force, including a chronic shortage of skilled construction workers. This has resulted in a tendency for work efficiency and quality to deteriorate. One method of overcoming this problem that has been urged forcefully upon us has been automation and robotization of construction operation. One of the areas where this has been attempted is in painting work.
Problem Definition
Wall painting, conventionally, has been carried out by human hands on scaffolds or ladders provisionally built around a subject wall. This, however, not only is a kind of work performed on dangerous elevated spots and in unclean environment but also requires extra work to take down the scaffolds, thus often making it difficult to shorten a construction term or to reduce cost. Moreover, painting of wall involves other manual tasks such as carrying, pushing, pulling and lifting of painting equipment. Carrying a spray gun, roller or even paint brush a long time can lead to repetitive stress injuries due to strenuous use of the same part of the body. [2]
Paint rollers and paint brushes are used by putting a cover on a handle and rolling it up and down a wall. The painter has to fill a paint tray with paint and roll the roller or put the brush end into it to get it wet with paint before using it on the wall. The painter has then to lift the roller which is loaded with paint and roll it on the wall or perform to and fro with the paint brush on the wall. These repetitive actions of pushing, pulling or lifting of heavy loads such as rollers, ladders or even paint tray may lead to back ache.
Moreover, when loading the roller or paint brush with paint, the amount of paint absorbed is often difficult to control and thus, the brush or roller is often overloaded. This causes paint to be wasted by either dripping or splattering. Further to that, if much force is not applied on the brush or roller, paint is wasted due to the absorption of paint in the paint brush or roller nap.
Most paint contains chemicals and compounds that are harmful to the environment and potentially harmful to painters. During painting process, painters may inhale those hazardous substances which can cause severe complications if exposed too much.
Automation and robotics have entered various fields of the construction industry, and paint work is no exception. Generally, conventional painting of the walls of buildings which is carried out using scaffolding or ladders has proved to be costly and labour-intensive. It is also unsafe as it involves working at considerable heights. Due to these problems, people are discouraged to opt for painters as job and as a result of that there have been problems involving quality due to the lack of skilled painters, and there is clearly an urgent need to improve the working environment and quality of the work being carried out.
Aims and Objectives
The aims and objectives of the project are to design a system for painting of wall which is:
Autonomous
Efficient
User-friendly
Transportable
Cost-effective
Reduce strenuous and repetitive task
Increase safety
Functional requirement of proposed system
Respond as per user’s input
Display user’s input
Move autonomously along wall
Paint wall at a maximum height of 1.25m and length as per user input
Paint only one color at a time
Make use of sensors to detect obstacles
Provide sonar alarms to indicate user intervention
May be able to determine whether system has reached required height and length.
Literature Review
Existing Automated Wall-Painting System
Warszawsky and Kahane , developed a robot for interior finishing tasks named “TAMIR”, and was used in four interior finishing tasks namely; painting, plastering, tiling and masonry. The robot has 6 DOF (Degrees Of Freedom) with an average reach of 1.7m and end effector payload of 30 kg. It is mounted on 3 wheeled mobile-robot which gives another 3 DOF. The platform moves between workstations and at each one it deploys four stabilizing legs. The robot arm used is the S-700 model made by General Motors, of 500 Kg weight. [3]
A scaled down robot setup for interior wall painting together with a multicolor spraying end tool were implemented by Naticchia and claimed to work in full scale without reduction in performance. The robot named “Pollock#1” had 6 DOF, a nominal reach of 0.4 m and a maximum payload of 4kg. It should be fixed on a 2 DOF hexapod for horizontal movement but was not actually used in experiments. [3]
A full scale mechanism for ceil painting was introduced by Aris . It had 3DOF without considering those of the platform, a working envelope of (84cm by 72 cm by 122 cm). Significant improvement in painting time and cost had been reached where 46 m_ of ceil were painted in 3.5 hours which is 1.5 times faster than manual painting. [3]
Outline of the Dissertation
The outline of the dissertation is classified as follows:
Introduction
Provide preliminary background information (to place your study in context).
Clarify your focus of study.
Specify your overall research aim and individual objectives.
Point out the value of your research.
Conceptual Design
A conceptual engineering study should logically consider the issues, concerns and goals that may be raised by an engineering request evaluate possible technical solutions and clearly report the findings and recommendations. It is intended to provide a comparative basis for decision making regarding further actions, without expenditure of exhaustive engineering efforts. Further preliminary engineering (e.g., equipment layouts, geological studies, testing and inspections) may then be suggested for the recommended conceptual solution prior to full project funding commitment and detailed engineering design.
Mechanical Design
Electrical and Electronic Hardware Design
Control system and Software Design
Implementation and Testing
In engineering, we normally formalize the testing process by referring to three distinct goals:
1. Validation
Simply stated, this test answers the questions: Have I built the right system? Does it satisfy the requirements? It may seem obvious, but you’d be surprised the number of times that the system which is built isn’t what is wanted at all. You should compare the system’s behaviour with the original requirements and system specification. Validation is extremely important and it should be carried out with great attention to detail.
2. Verification
In this case, the questions are: Have I built the system right? Is it computing the right answer? This is what most people understand by testing.
3. Evaluation
Finally, we ask: How good is the system? Again, the hallmark of good engineering: we seek to assess the systems performance and compare it to that of other similar systems. Ideally, you should identify some quantitative metric by which to 11 compare the systems, since numbers are the best and perhaps the only way to objectively describe performance. For example, the mean time between failures (MTBF) or the number of incorrect rejections in a pattern recognition system. Quite often, we use statistical measures as our comparative metric, e.g. the mean and standard deviation of some performance measure when the system is subjected to a large variety of input parameters and conditions. [4]
Conclusion and Recommendations
Conceptual Design
Design Process
The engineering design process is the set of steps that a designer takes to go from first, identifying a problem or need to, at the end, creating and developing a solution that solves the problem or meets the need.
The steps of the engineering design process are to:
Define the Problem
Do Background Research
Specify Requirements
Create Alternative Solutions
Choose the Best Solution
Do Development Work
Build a Prototype
Test and Redesign
During the engineering design process, designers frequently jump back and forth between steps. Going back to earlier steps is common. This way of working is called iteration, and is used to refine the design.
A flow diagram outlining eight steps for the 5-12 engineering design process
Description of desired painting system
The system once on will require the user to choose the mode of painting (Either Mode 1 or Mode 2).
Microcontroller verifies the data input from the user and process it. Error message is displayed if wrong data is input.
If user chooses Mode 1
User has the ability to move the robot using the buttons on the keypad.
A button will be available to the user for the latter to activate the trigger on the paint sprayer. Thus, the user will be able to paint the place he wants.
The user may move the robot horizontally as long as the horizontal motion button is pressed. Although, these buttons are pressed, if the robot detects an obstacle in the direction it is moving, it will stop. The presence of an obstacle will be detected by an ultrasonic sensor.
For the vertical movement, the user has to press the two vertical movement buttons. When the sprayer has reached the maximum height on the square threaded screw A, a limit switch will be activated signaling that the sprayer has reached the maximum position on extension rod A. If the user continues to press the upward button, stepper motor A will stop and that of B will start causing the sprayer to rise due to the extension of rod B. When B reaches a maximum position, another limit switch will be activated indicating that the maximum height achievable by the sprayer has been reached.
Same principle will apply when lowering the sprayer.
If user chooses Mode 2
The user will have to input the length and height of the wall. The user may use the keypad to enter the distance. Moreover, the input required or data input will be displayed on the LCD.
Once, the length and height have been input, the robot will start functioning. The length may be of any value. There is no limitation of the horizontal movement. The robot will stop only the required distance has been moved or an obstacle has been detected. There will be two square-threaded screws which will help for the vertical motion. For height less than 50cm, only square-threaded rod A will be used and for height between 50cm and 125cm, both rods will be used.
The robot will move to and fro on the vertical axis, and then move a predefined distance on the horizontal axis and again upward and downward motion. It will continue like that until the required length and height of the wall is painted.
Once, an obstacle is detected, the robot will stop and the user will have to re-input the height and length but now with reference to the place it has stopped
Flowchart of desired painting system
IS SPRAY BUTTON PRESSED?
PAINTING PROCESS
IS END BUTTON PRESSED?
END
START
SELECT
MODE
MOVE ROBOT MANUALLY USING DIRECTION BUTTONS
DOES ROBOT OR ARM ENCOUNTER ANY OBSTACLE?
OUTPUT BEEP SOUND AS WARNING
2
1
YES
NO
NO
YES
NO
YES
NO
NO
ROBOT MOVE HORIZONTALLY A PREDEFINED DISTANCE
DOES ROBOT ENCOUNTER OBSTECLE?
2
ENTER LENGTH ANF HEIGHT
ARM OF ROBOT MOVE UPWARD FIRST AT A GIVEN HEIGHT
DOES ROBOT ENCOUNTER OBSTECLE?
STOP PAINTING AND RETRACT
YES
ARM OF ROBOT RETRACTS COMPLETELY
HAS THE ROBOT MOVED THE REQUIRED LENGTH?
END
YES
NO
YES
Design of Desired Painting Robot
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Design Overview
The design of the desired painting system will be classified into three main parts:
Mechanical design
Electrical design
Software and control system design
Mechanical design
Vertical Motion
The sprayer must move upward and downward. This can be achieved by converting the rotary motion of the motor into linear motion. Several possibilities are available for this conversion such as power screw, bell crank, cams, gears, pulleys among others.
The painting mechanism should have the following requirements:
Easy to manufacture
Low cost
Robust
Light
Low maintenance
Good resolution
Horizontal motion
For horizontal motion, wheels are considered best for locomotion. The simplest way is to use the direct method in which the wheel’s hub is connected to the motor. There are different types of wheels such as Standard/Fixed wheels, Orientable wheel, Ball wheel, Omni wheels.
Motor
There are mainly two types of motor that can be used:
DC Motor
Stepper Motor
Electrical design
Stepper Motor Driver
Stepper motor driver is used to drive the motor. Pulse is sent from the driver to activate the motion of the motor. DIR on the driver is used to reverse the rotation of the motor.
Microcontroller
Motor Driver
Stepper Motor
Voltage Source
Input keypad
The user will use the input keypad to choose the mode of painting he wants and also to input the length and height of walls
Voltage Source
Input Keypad
Microcontroller
Sensors
Ultrasonic range sensors will be used to detect obstacle in the path the robot is moving. The output from the sensor, being analog, must be fed to the ADC port of the microcontroller for the data to be converted to digital.
Voltage Source
Sensors
Microcontroller
Pending Tasks
Till date, most of the researches concerning the implementation of the proposed painting robot have already been done. The pending tasks are as such:
Construction of square-threaded Screw
Construction of Robot
Installation of lead screw on robot
Refining mechanical works
Stepper Motor Connection
Designing and Implementation of Electrical Circuits
Programming of Microcontroller
Implementation and Testing
Documentation
Ghatt Chart
Week remaining
week 1
week 2
week 3
week 4
week 5
week 6
Week7
week 8
week 9
week 10
week 11
week 12
week 13
week 14
week 15
week 16
week 17
Week18
Construction of square-threaded Screw
Construction of Robot
Installation of lead screw on robot
Refining mechanical works
Stepper Motor Connection
Electrical Circuits
Programming of MIcrocontroller
Implementation and Testing
Documentation