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Final Report on Cut to length controller using P89LPC932

Nov 18, 2014

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a report on Cut to length controller, using uc P89LPC932 for servo drive and servo motor(excluding the source code).this device is a kind of CNC low cost machine and can be used in place of Micro processor for controlling the servos.

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Cut to Length Controller

3. Study Of 1. Introduction . . . . . . Existing System

Scenario and Progress of Industry Automation

Overview of the System

Operation Overview and Problem Definitions

___________________________________________________________________________________________ V.T Patel Department Of Electronics & Communication Engineering 1

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Cut to Length Controller

1.1 SCENARIO & PROGRESS OF INDUSTRIAL AUTOMATION

During the eighties emerged a profuse literature pointing at a number of potential advantages of recent microelectronics-based industrial automation for developing countries. It is claimed that industrial automation is leading to fundamental changes in production organizations , optimal scales of output and economic scope , vertical integration and the relationship between large and small firms that would generally be favorable to any country.

A new phase in the replacement of human effort by machines began to emerge around the early twentieth century with the development of industrial automation. Unlike mechanization industrial automation not only involves the replacement of physical effort by machines but entails the displacement of some of the decision making capabilities of the operator. It is based on the concept of feedback control which consists of a procedure of measuring and inspecting or sensing the evaluation and processing of this information in relation to theory or algorithm of the process, and an output of instructions as a response if required. Feed back control allows for the development of more flexible machines and production processes.

The foundations of the industrial automation need to be traced to the development of quantum mechanics, classical mechanics, electronics and the essential one, process theory, which describes the behavior of output variables as a function of adjustable and non adjustable variables and time. Also the inventions such as the vacuum tube , the transistor, the integrated circuit and the microprocessor, which led to the emergence of the microelectronics, and a wide variety of new sensing devices are essential to the revolution of the industrial automation. Process control theory has provided knowledge on the principles of control, on the ways of implementing these principles, and on the mathematical ___________________________________________________________________________________________ V.T Patel Department Of Electronics & Communication Engineering 2

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Cut to Length Controller

models to represent processes. Microelectronics, i.e. electronic using very small solid state components, provided devices for storing, processing and computing information that are notably smaller and diminishing in size, of an exceedingly high and increasing speed and reliability, and , of very low and decreasing costs.

The introduction of digital computers in the 1960s offered the possibility of breaking away from previous unreliable electromechanical controls and move into faster, reliable and more accurate devices, capable of data storing and processing and of performing a series of complex mathematical operations. But , by and large, early computers were a failure because of constant breakdowns due to their sensitivity to the external environment leading to expensive back-up measures and difficulties in developing models and writing programs that took all intervening variables into account. This situation changed drastically the advent of microelectronics. Since 1975, devices such as programmable logic controllers, micro and process computers have been developed. Together with appropriate software and novel measuring instrumentation, also microelectronics based , the new control devices are simultaneously capable of data gathering, processing and storing, computing ,regulating controlling, interfacing with the operator and communicating with other devices and outside the system with or without human intervention.

Because of the emphasis on advance and high tech equipments with feedback control as the defining factor, industrial automation includes a wide variety of self-regulating equipment which is in almost any industry, It also includes any combination of machines which are jointly controlled from a computer. And, it possibly consists of parts of plants or even whole factories which are completely unmanned and computer controlled, although factories of the future still seem to be a long way away.

The diffusion of industrial automation since the advent of microelectronics has proceeded at a very fast rate. In continuous process industries more powerful ___________________________________________________________________________________________ V.T Patel Department Of Electronics & Communication Engineering 3

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Cut to Length Controller

and sophisticated process control units and sensors were developed ,while in batch industries, particularly in mechanical engineering , new process equipment such as numerically and computer controlled machine tools, computer-aided design and flexible manufacturing systems emerged.

1.2

OVERVIEW OF THE SYSTEM (C2L)Automatic continuous cutting along a straight line required the combined accurate positioning of the tool and work piece along a length. This involves a complex set of movements the commands for which, it is believed at the real time, can be conveyed to the motor of the machines tool through a device or servomechanism which has created digital signals corresponding to numbers. These signals were then compared with signals arising from the actual position of the tool and work piece prompting corrective action if necessary.

Perhaps the best way to start with is the analysis of the system objectives. In as much as automated equipment requires automatic control, data on the use of industrial control and instrumentation, should provide an idea of the real time implementation.

Here first we are going to see the purpose of the system and then we come to know how we have derived the system objectives along with the application background.

1.2.1 Purpose of the system :The purpose of designing such system is to provide a cost effective and precise control over a servo drive for a dedicated application and enhanced functionality of servo drive MP-controller.

___________________________________________________________________________________________ V.T Patel Department Of Electronics & Communication Engineering 4

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Cut to Length Controller

( Here dedicated application is in terms of controlling servo device in such way, that the servo motor connected, rotates for a derived number of pulses and gives the exact desired length of the sheet without any damage. )

1.2.2

Objectives of the system :The system have the following objectives such that it is reliable enough to apply for an industrial application. The objectives are :

1) The system must have the basic functionality of servo drive controlling MP, such that system can completely replace the MP unit. 2) The system must be able to provide pulse train in frequency range of 1 to 70 KHz for the pulse potion mode of the servo drive. 3) The system must be able to sense the mechanical assembly failure such that it will resume the functionality with the previous parameters fed. 4) The mechanical assembly should be controlled such a way that desired length of the sheet can be achieved without any damage and the length must be in mm. 5) The system must be able to communicate human interfaces like LCD or HMI. 6) The system should be very cost effective and highly efficient. 7) The parameters listed below can be easily inserted through any media to the system: 1. Length of the desired sheet in mm. 2. Diameter of the roller 3. Gear ratio 4. cutter on/off duration 5. Calibration

___________________________________________________________________________________________ V.T Patel Department Of Electronics & Communication Engineering 5

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Cut to Length Controller

1.2.3

Application Background :The following diagram shown is the application diagram

Figure 1.1 Application Background Here as shown in the diagram the system has to control the right side belt assembly by controlling the rollers such that rotation of the rollers provide the forward motion of belt and hence the sheet. Here the rotation of the roller is such that it provides the exact desired length of the sheet. Such controlling action of the rollers and hence the entire right sided belt assembly is achieved by a servo motor and servo drive with C2L unit. Here the C2L unit provides the derived pulse train as per the user requirement to the servo drive. Here the servo drive is set to the pulse position mode, such it gives the signal to servo motor in accordance with the number of pulses in pulse train. Here the belt assembly on the right side, moves with the constant speed along with the take up drum.

___________________________________________________________________________________________ V.T Patel Department Of Electronics & Communication Engineering 6

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Cut to Length Controller

1.3

OPERATION OVERVIEW AND PROBLEM DEFINITIONSNow from the application background we come to know the handling of system components. But there are many difficulties associated with the system, which must be considered and also the provision of such difficulty must be provided as a controlling action of system itself.

1.3.1 Operation Overview with possible arrangement :The entire system can be controlled by providing proximity switches as shown in the figure. There can be mainly three proximity switches, one for starting the cutting operation called start proximity, and rest two a