PICK AND PLACE ROBOTS

PICK AND PLACE ROBOTS

• Pick and place robot speeds up the process of picking parts up and placing them in new locations, while also increasing production rates.The consistency, quality and repeatability  of a pick and place robot system is unmatched.These systems are also versatile and can be reprogrammed and tooled to provide multiple applications for consumers.

• An increase in output with a pick and place robot system offer long-term savings to companies with the advancements in technology and affordability of robots, more pick and place robots are being installed for automation applications.

    The basic form of pick and place robot is shown in Fig.

• The robot has three axis about which motion can occur.The following movements are required for the robot.

1. clockwise,anticlockwise,rotation of robot unit on its own axis.
2. Linear movement of arm horizontally. i.e extension or contraction of the arm.
3. Up and down movement of the arm.
4. open and close movement of the gripper.

• The foresaid movements can be obtained by pneumatic cylinder which is operated by solenoid valves with limit switches.Limit switches are used to indicate when a motion is completed. 

• The clockwise rotation of the robot unit on its base can be obtained from a piston and cylinder arrangement during pistons forward movement. Similarly counter clockwise rotation can be obtained during backward movement of the piston in cylinder.

APPLICATIONS:

1. It can be used in Production industry.

2. In mass production.

3. In Automobile Industry.

4.High speed assembly.

5.Packing

ADVANTAGES:

               Quality: 

                Industrial automated mechanical arm have the capacity to dramatically improve product                 quality. Applications are performed with precision and high repeatability every time. This                 level of consistency can be hard to achieve any other way.

               Production:
         With mechanical arm, throughput speeds increase, which directly impacts production.                  Because an automated mechanical arm has the ability to work at a constant speed                      without pausing for breaks, sleep, vacations, it has the potential to produce more than a                human worker.

              Safety:
         mechanical arm increase workplace safety. Workers are moved to supervisory roles                      where they no longer have to perform dangerous applications in hazardous settings.

              Savings: 
         Improved worker safety leads to financial savings.Automated mechanical arm also offer                  untiring performance which saves valuable time. Their movements are always exact,                       minimizing material waste.

DIS-ADVANTAGES:

Expense:
Regular maintenance needs can have a financial toll as well.

ROI: 
Incorporating industrial robots does not guarantee results. Without planning, companies can have difficulty achieving their goals.

Expertise:
Employees will require training program and interact with the new robotic equipment. This normally takes time and financial output.

Safety:
Robots may protect workers from some hazards, but in the meantime, their very presence can create other safety problems. These new dangers must be taken into consideration.

WINDSCREEN WIPER WING STEPPER MOTOR CONTROL

 Windscreen wiper wing stepper motor control:

·        Windscreen wiper is a device which is used to clear the front glass of the cars,buses, train etc., during raining days. It will oscillate an arm back and forth in an arc like a windscreen wiper. A traditional mechanical solution for this problem is shown in fig.

·    It uses a brush-less stepper motor.It uses a principle of four-bar mechanisms.It is using a worm and gear to reduce the speed and to increase the torque up to 50:1. It consists of a crank which rotates about its center and a connecting rod which converts rotary movement to linear movement of the linkage .  An end of a connecting rod is connected to the crank and other with wiper arm. Rotation of crank causes connecting rod to impart an oscillatory motion to wiper arm. We can also have wiper arm in the passenger side, a linkage will connect both the sides.

·     An alternative mechatronics approach for this problem is to use a stepper motor. For operating a stepper motor a microprocessor or a micro controller can be used.The input to the stepper motor is required to cause it to rotate a number of steps in one direction and reversing the same number of steps in other direction while the data is reversed.

  

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Rain Sensor:

·         When the vehicle is started the rain sensor gets the supply power and it will scan for the moisture content in the windshield.The sensor is interfaced with the micro controller. An infrared beam is reflected off the outside surface of the windshield to the infrared sensor array. When moisture strikes the windshield, the system experiences an interruption to its infrared beam. Advanced analog and  digital signal processing determines the intensity of rain or snow. The sensor communicates to the wiper control module to switch on the wiper motor and controls the wipers automatically according to the moisture intensity detected.

• The sensor will send output voltage according to the rain amount. If there is no rain then the voltage will be more than 4V and if it is raining the output will be less than 4V. When rain is detected then the motor will be turned on at lower speed. If the voltage drops less than 2.5V then the motor will be turned ON at higher speed.

TYPES:

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b

MECHATRONICS SYSTEM DESIGN AND APPLICATIONS

TRADITIONAL AND MECHATRONICS DESIGN

    

         In traditional design, the components are designed through mechanical, hydraulic or                            pneumatic components and principles. But in mechatronics approach, mechanical,                              electronics, computer technology and control engineering principles are included to design a                  system.

         For example design of weighing scale might be considered only in terms of the compression of springs and a mechanism used to convert the motion of spring into rotation of shaft and hence movements of a pointer across a scale.  In this design measurement of weight is depended on the position of weight on the scale.

·        In mechatronics design, the spring might be replaced by load cells with strain gauges and output from them used with a microprocessor to provide a digital readout of the weight on an LED display.

  

·        Similarly the traditional design of the temperature control for a central AC system involves a bimetallic thermostat in a closed loop control system.The basic principle behind this system is that the bending of the bimetallic strip changes as the temperature change and is used to operate an ON/OFF switch for the temperature control of the AC system.

·        The same system can be modified by mechatronics approach.  This system uses a microprocessor controlled thermocouple as the sensor. Such a system has many advantages over traditional system.

·       The bimetallic thermostat is less sensitive compared to the thermodiode.  Therefore the temperature is not accurately controlled.   Also it is not suitable for having different temperature at different time of the day because it is very difficult to achieve.

     But the microprocessor controlled thermodiode( Themodiode: application of thermal diode is based on its property to change voltage across it linearly according to temperature. As the temperature increases, diodes forward voltage decreases.)system can overcome fore said difficulties and is giving precision and programmed control. This system is much more flexible.

       Weighing scales:

·        Consider the simple weighing machine which is used to indicate the weight of a person standing on it.The important requirement of this weighing machine is to indicate the weight of the person with reasonable   speed and accuracy and be independent of whereon the platform the person stand.

·         The traditional mechanical system for this problem is to use the weight of the person on the platform to deflect an arrangement of two parallel leaf springs as shown in fig.

·      The deflection of the leaf spring is transferred to the rack and pinion arrangement where the linear movement of rack is converted into rotary motion of the pinion about the horizontal axis.  The rotary motion is transferred to the movement of a pointer across a scale through bevel gears.  With this arrangement the deflection is independent of where on the platform the person stands.

·      The mechatronics solution for this problem involves the use of a microprocessor. The basic principle behind this approach is to use load cells employing electrical resistance strain gauges.