Reach Stacker

A reach stacker is a vehicle used for handling inter-modal cargo containers in small terminals or a medium-sized ports. Reach stacker are able to transport a container short distances very quickly and pile them in various rows depending on its access.





Reach Stacker Functions

The functions to hand the container through Reach Stacker are as following.

Hosting

Moving the container upwards or in other words increasing the hight of container is known as hosting. This hosting system is dependent on hydraulics.

Lowering

The counter action of hosting or moving the container downwards or in other words decreasing the hight of container is known as lowering. This lowering system is dependent on hydraulics.

Telex Out

To achieve more hight or to move the container away form Reach Stacker is know as telex Out.

  

Telex In

The counter action of Telex Out is known as Telex In.

Swing Clock Wise

The angular motion of a spreader, clock wise on XY-plane is known as swing.

The spreader is a part of Reach Stacker which holds the container.

Swing Clock Wise

The angular motion of a spreader, counter clock wise on XY-plane is known as swing.

Side Shit Right

The linear motion of a spreader, towards the right side form the reference of operator, is known as Side Shift  Right.

This movement is use to balance the spreader with load or without load.

Side Shift Left

The linear motion of a spreader, towards the left side form the reference of operator, is known as Side Shift  Left.
This movement is use to balance the spreader with load or without load.

The following above eight function are related to container handling functions of Reach Stacker.

These functions are dependent upon hydraulics.

Hydraulics Speed controller

The speed of hydraulic is controlled by controlling the flow of hydraulic fluid in hydraulics.
The control valve are used to control the fluid.    

Hydraulics Control Valves

Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in response to signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.

Solenoid is use to control the flow of fluid.

The Solenoid used by the Reach Stacker is of 24 volts. As you vary the voltages to the solenoid the flow of fluid varies, this controls the speed of hydraulics.

Smart High side Power Switch ( BTS-432)

This switch is used to control the speed of flow of fluid. May be other switches are available in the market but this switch is used by me.

The 24volts are given to Pin 3 at Vbb.

And a PWM is given to Pin 2 at IN.

The greater the PWM width the higher the voltages you receive at output Pin 5. 

Pin 4 is of status pin which is used to let you know about the shot circuit. By getting hight or low according to the model of the chip.

Formula for voltages at output.

For further details the datasheet is available at

http://www.datasheetcatalog.org/datasheet/infineon/1-bts432f2.pdf

Micro controller

Well any micro controller can be used to control the width of PWM.

I am going to use AT-TINY 13A.

AT-TINY 13A

Its as 8-pin in PDIP package with Six Programmable I/O Lines. 4-channel, 10-bit ADC with Internal Voltage Reference. One 8-bit Timer/Counter with Prescaler and Two PWM Channels.

With the help of Two PWM channels you can control any two of the functions explained above.

8-bit Timer/Counter

Timer/Counter0 is a general purpose 8-bit Timer/Counter module, with two independent Output

Compare Units, and with PWM support. It allows accurate program execution timing (event management) and wave generation.

TCCR0A =

        (1 << COM0A1) |    // set OC0A on compare match, clear at TOP

        (1 << COM0B1) |    // set OC0B on compare match, clear at TOP

        (1 << WGM00);    // PWM phase correction mode

TO generate 150Hz PWM frequency I will be using 4.8MHz internal clock for AT ATINT 13A.

The formula is given in datasheet to generate required frequency set 64 pre-scaler.

TCCR0B = (1 << CS01) |  // prescaler = 64

(1 << CS00);

10-bit ADC

ADC 2 and ADC 3 is used for the input coming from joystick.

ADMUX =

        (1 << ADLAR) |     // left shift result

        (1 << MUX1);       // use ADC2 for input (PB4) (to start)

   ADCSRA =

        (1 << ADEN)  |     // Enable ADC

        (1 << ADATE) |     // auto trigger enable

        (1 << ADIE)  |     // enable ADC interrupt

        (1 << ADPS0) |     // Prescaler 

        (1 << ADPS1) |      //   CLOCK/128

(1 << ADPS2);

For further details the datasheet is available at

http://www.atmel.com/Images/doc2535.pdf

Joystick

The Reach Stacker joystick basic contains potentiometer inside it. When you moving the joystick the resistance varies and the variation is sense by the ADC of AT TINY 13A.

On the basses of ADC data the PWM is generated.

OCR0B/OCR0A = ADCH ;

Movement of joytick

Postive Y-axis = Lowering

Negative Y-axis = hosting

Postive X-axis = Telex In

Negative X-axis = Telex Out

Top Right Button = Swing Clock Wise (SCW)

Top Left Button = Swing Counter Clock Wise (SCCW)

Blow Swing Right Button = Side Shift Right (SSR)

Blow Swing Left Button = Side Shift Left (SSL)