International Journal of Engineering Trends and Technology (IJETT) – Volume 10 Number 3 - Apr 2014
RF Transceiver Based Hand-Motion Crane Control Systems
1
Mercy Lurthu S, 2K.Seetha Lakshmi
1
PG Student, 2Assistant Professor
Department of Electronics and Communication Engineering
DMI College of Engineering, Chennai-600123, India.
Abstract-Human operators have facing many
difficulties while driving cranes accurately,and safely
because the heavy structure of the crane responds slowly
and its payload oscillates.Manipulation difficulty is
increased by non-intuitive control interfaces (such as
buttons,levers,and joysticks).It needs more experience to
master.This paper presents a new model control system
that allows operators to drive a crane by simply moving a
hand,which is given as the input of the sensor.The output
of the sensor will be encrypted and it sends through the
RF transmitter.In RF receiver side the signals will be
decrypted and the crane will be controlled .H
eavy
II.REVOLUTION
SYSTEM
OF
CRANE
CONTROL
Nowadays there are many techniques introduced with the
crane control system.Camera may be attached with the trolley
and payload for finding unnecessary oscillation in the
payload.
Cranes can be used in construction sites,shipyards and to
remove vehicles and heavy weighted materials from one
location to another.
II.SYSTEM ANALYSIS OF THE PROCESS
Keywords- Cranes,3 axis accelerometer, sensor based,wireless
transmission, radio frequency (RF Transceiver).
I. INTRODUCTION
Cranes play a major role in maintaining the major
prominent role of modern-day industries. We can see the
importance of the crane at harbors, construction sites,
warehouses, and in a wide variety of biggest and heavy
material-handling applications. Nowadays the population of
industries gets increased, the number of manufacturing of the
cranes are also gets increased. When the load is applied to
trolley of the crane ,it oscillates like a pendulum or a double
pendulum.
Furthermore, the crane operator has to face many challenges
because of their environmental work conditions such as,it may
be extreme heat or it is as cold.And whenever the crane
rotates,from the vibration of the motor,the drivers of the
cranes will be suffering from numerous health problems.In
this existing system,the crane operator has to stand near to the
crane,and they have to use separate tags for “Left (L)”, and
“Right (R)” side tilts at the correct time and in the correct
sequence. For each angle of movement the operator has to
rotate their body in the desired direction.And also they have to
monitor the crane continuously and it is a risking process
because the operator stands near to the crane and suppose
heavy load may lead to oscillate and unexpected accidents.
ISSN: 2231-5381
Fig 1.Block Diagram of Transmitter Unit
a. 3 Axis Accelerometer : The accelerometer is fed as an
analog input to the microcontroller. It has three wires. Each
wire is connected to ADC channel of ATMEL microcontroller
and the supply and ground pins has been connected .
b. Atmel Microcontroller : The Atmel microcontroller is fed
with the set of input and output pins.
c. Encryption : HT12E is an encoder integrated circuit of 212
series of encoders. They are paired with 212 series of
decoders for use in remote control system applications. It is
mainly used in interfacing RF and infrared circuits. The
chosen pair of encoder/decoder should have same number of
addresses and data format.
d. RF Transmitter : All RF waves have characteristics that
vary to define the wave. Some of these properties can be
modified to modulate information onto the wave.These
properties are wavelength, frequency, amplitude, and phase.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 10 Number 3 - Apr 2014
element and to provide a signal to the external world through
an I2C/SPI serial interface.
ii)Controller IC : The complete measurement chain is
composed by a low-noise capacitive amplifier which converts
into an analog voltage the capacitive unbalancing of the
MEMS sensor and by analog-to-digital converters.The
acceleration data may be accessed through an I2C/SPI
interface thus making the device particularly suitable for
direct interfacing with a microcontroller.
Fig 2. Block Diagram of Receiver unit
a .RF Receiver : The RF Receiver circuit is used to receive
the signals from the transmitter portable unit .
b. Decryption : HT12D is a decoder integrated circuit of
212 series of decoders. They are paired with 212 series of
encoders for use in remote control system applications. It is
mainly used in interfacing RF and infrared circuits. The
chosen pair of encoder/decoder should have same number of
addresses and data format
c. Servo Motor : Depending upon the values obtained from
the accelerometer the SERVO MOTOR locates the exact
position and the angle of the crane system's trolley have been
controlled.The values which are received on the
microcontroller will be sent through PORT D of the
microcontroller and then it will sent through the relays and
also drivers .
d. Dc Motor : Depending upon the values detected from the
acceleromete the DC MOTOR can be used to take the payload
by using the trolley of the crane.
III.FUNCTIONS OF THE COMPONENTS
i).MEMS Sensor : The LIS35DE is an ultra compact lowpower three axis linear accelerometer. It includes a sensing
element and an IC interface able to provide the measured
acceleration to the external world through I2C/SPI serial
interface.
The sensing element, capable of detecting the
acceleration, is manufactured using a dedicated process
developed by ST to produce inertial sensors and actuators in
silicon.The IC interface is manufactured using a CMOS
process that allows to design a dedicated circuit which is
trimmed to better match the sensing element characteristics.
The LIS35DE is a ultracompact, low-power, digital
output 3-axis linear accelerometer packaged in a LGA
package. The complete device includes a sensing element and
an IC interface able to take the information from the sensing
ISSN: 2231-5381
The LIS35DE features a Data-Ready signal (RDY) which
indicates when a new set of measured acceleration data is
available thus simplifying data synchronization in the digital
system that uses the device.The LIS35DE may also be
configured to generate an inertial Wake-Up and Free-Fall
interrupt signal accordingly to a programmed acceleration
event along the enabled axes.Both Free-Fall and Wake-Up can
be available simultaneously on two different pins.
iii).RF Transceiver : Short for Radio Frequency, RF refers to
the frequencies that fall within the electromagnetic spectrum
associated with radio wave propagation. When applied to an
antenna, RF current creates electromagnetic fields that
propagate the applied signal through space. Any RF field has
a wavelength that is inversely proportional to the frequency.
This means that the frequency of an RF signal is inversely
proportional to the wavelength of the field. The Parallax 433
MHz RF Transceiver utilizes a frequency of 433 MHz, this
works out to be a wavelength of approximately 0.69 meters.
iv).HT12E Encoder :
HT12E is an encoder integrated
circuit of 212 series of encoders. They are paired with 212
series of decoders for use in remote control system
applications. It is mainly used in interfacing RF and infrared
circuits. The chosen pair of encoder/decoder should have
same number of addresses and data format. Simply put,
HT12E converts the parallel inputs into serial output. It
encodes the 12 bit parallel data into serial for transmission
through an RF transmitter. These 12 bits are divided into 8
address bits and 4 data bits.
HT12E has a transmission enable pin which is active low.
When a trigger signal is received on TE pin, the programmed
addresses/data are transmitted together with the header bits via
an RF or an infrared transmission medium. HT12E begins a 4word transmission cycle upon receipt of a transmission
enable. This cycle is repeated as long as TE is kept low. As
soon as TE returns to high, the encoder output completes its
final cycle and then stops.
HT12E has a transmission enable pin which is active low.
When a trigger signal is received on TE pin, the programmed
addresses/data are transmitted together with the header bits via
an RF or an infrared transmission medium.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 10 Number 3 - Apr 2014
v)HT12D Decoder : The 212 series of decoders provides
various combinations of addresses and data pins in different
packages so as to pair with the 212 series of encoders.
The decoders receive data that are transmitted by an encoder
and interpret the first N bits of code period as addresses and
the last 12 N bits as data, where N is the address code number.
A signal on the DIN pin activates the oscillator which in turn
decodes the incoming address and data. The decoders will
then check the received address three times continuously.
vi)Servo Motor : The integrated circuit and pot inside a servo
are used to implement a closed-loop position control system.
The input control signal to a servo is known as a pulse-code
modulated (PCM) signal. The figure illustrates the protocol
for moving the servo to a given position.
The servo expects a train of pulses of varying widths. The
pulses are repeated at a given period, typically set at 20
ms(50Hz). The width of the pulse is the code that signifies to
what position the shaft should turn. The center position is
usually attained with 1.3-1.5ms wide pulses, while pulse
widths varying from 0.7-1ms will command positions all the
way to the right (left), and pulse widths of 1.7-2ms all the way
to the left (right).
vii)DC Motor : An electromechanical energy conversion
device is essentially a medium of transfer between an input
side and an output side. Three electrical machines (DC,
induction and synchronous) are used extensively for
electromechanical energy conversion. Electromechanical
energy conversion occurs when there is a change in magnetic
flux linking a coil, associated with mechanical motion.
7. An analysis plot is to be produced as a result.
8. The hardware implementation of this project will be done
using the ATMEL 16 bit controller .
IV.CONTROLLER USED
PD Controller : D mode is used when prediction of the error
can improve control or when it necessary to stabilize the
system. From the frequency characteristic of D element it can
be seen that it has phase lead of 90°.
Often derivative is not taken from the error signal but from
the system output variable. This is done to avoid effects of the
sudden change of the reference input that will cause sudden
change in the value of error signal. Sudden Change in error
signal will cause sudden change in control output. To avoid
that it is suitable to design D mode to be proportional to the
change of the output variable.
PD controller is often used in control of moving objects
such are flying and underwater vehicles, ships, rockets etc.
One of the reason is in stabilizing effect of PD controller on
sudden changes in heading variable y(t). Often a "rate gyro"
for velocity measurement is used as sensor of heading change
of moving object.
VI. ANALYSIS FROM THE SIMULATION
PROTEUS Software is used for simulating the embedded
circuits.
TRANSMITTER :
The input is electrical energy (from the supply source), and
the output is mechanical energy (to the load).
IV. WORK FLOW MODEL OF THE SYSTEM
1. Any tilt change in the hand movements are sensed by the 3
axis accelerometer and the axis values in 3 dimensions is sent
to the microcontroller.
2.The values read by the microcontroller are sent towards the
encrypting .The signals which are encrypted will be
transmitted through the RF transmitter via MAX232.
3. The values that are received from the detecting node are
sent to the system via RF receiver (TX).
Fig 3. Analysis of Transmitter
Explanation : The hand signals are given as input to the 3
4.The values are displayed in the system and are analysed for
the detection of abnormalities using PROTEUS software
modules.
5.With the help of the input shaping and the residual vibration
control the information present in the hand movements will
be given to a crane module.
ISSN: 2231-5381
axis accelerometer.It will convert that analog signals into
3directions .The 3 axis accelerometer is connected to the Adc
input of the micro controller.The digital values which are
generated from the microcontroller will be encrypted and it
will be sent through the RF transmitter .So that these signals
will not be collapsed with the other signals .RF signals are
having the capability to travel through the obstacles also .
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International Journal of Engineering Trends and Technology (IJETT) – Volume 10 Number 3 - Apr 2014
RECEIVER :
We can make higher frequency communication instead of
the RF range. It can be included that another way of detecting
the payloads including the camera along the hoistway also can
be included in this .
REFERENCES
[1] E. Maleki and W. Singhose. “Dynamics Analysis and Nonlinear
Control of an Offshore Boom Crane,” Industrial Electronics, IEEE
Transactions on (vol:61, Issue:1), Jan.2014
[2] O. Sawodny, A. Hildebrandt,, “‘Generic Approach to Stability Under
Time-Varying Delay in tele-operation : Application to the Position-Error
Control of a Gantry Crane’’, Mechatronics, IEEE/ASME (VOL:18,
ISSUE:5), OCT.2013
[3]G.Parker,K.Groom,”Experimental verification of a command shaping
boom crane” IN PROC.AMER.CONTROL.CONF.SAN.DEIGO,CA,1999
Fig 4. Analysis of Receiver
Explanation : The received RF signals will be given to the
microcontroller through the UART.The signals will be
decrypted by using HT12D and these will be given to the
output motor drives .The motor drivers will convert the
signals into pulses .The pulses are given to the servo motor
and dc motor.According to the width of the pulses the motor
‘s speed and angular position of the motor and also the crane
will be controlled .Depend upon the hand motion the width of
the pulses will be varied Relays are use as the controlling
element of that driving motors .
[6]O.Sawodny,A. Hildebrandt, and K. Schneider, “Control design for
therotation of crane loads for boom cranes,” in Proc. IEEE Int. Conf.
Robot.Autom., 2003, vol. 2, pp. 2182–2187.
[7] T. Mahl, O. Sawodny, and K. Schneider, “strategical control strategy
for boom cranes in radial direction,” in Proc. Amer. Control Conf.,New
York, 2007, pp. 25–30
[8] E. Maleki and W. Singhose. (2011). Dynamics and control of a
smallscaleboom crane. J. Comput. Nonlinear Dyn. [Online]. 6(3), p. 031015.
VII. CONCLUSION
A controlled interface and control systems have been
developed that allows operators to drive a crane by moving a
hand. The intuitive hand-motion interface is an improvement
over traditional interfaces such as a push-button pendent
because it removes the cognitive process required to translate
the desired manipulation path into a sequence of button
presses. The P and PD hand-motion controllers experimentally
validated the effectiveness of the new interface.
However, their performances were impeded by signal
noise. An ON–OFF controller was developed that not only
avoids many noise-associated problems, but also greatly
reduces
design
and
implementation
complexities
.Implementation of accelerometer and RF circuit using
microcontroller is presented. However, with the help of z-axis,
upward and downward movement of the system can be
controlled. The presented system can be used for the military
applications and spy operations, where one can control the
movement merely by moving the accelerometer rather than
using a remote control.
Future Enhancement and points
The crane model in this study was simulated using a
PROTEUS software. To eliminate realistic sea disturbance
induced payload swing on shipboard cranes, a more realistic
sea model is required.
ISSN: 2231-5381
[4]K.Kuchler,”Active control of the offshore crane using the Prediction
control of the vessel’s motion”,ATMR.CONF.IEEE TRANSACTIONS
MECH NOV.12
[5]J.Nupert.T.Mahl,” A Nonlinear control strategy for boom cranes in
radial direction.”IN PROC. AMER.CONTROL.CONF., NEW YORK2007.
[9] S. Kuchler, T. Mahl, J. Neupert, K. Schneider, and O. Sawodny, “Active
control for an offshore crane using prediction of the vessel’s
motion,”IEEE/ASME Trans. Mechatronics, vol. 16, no. 2, pp. 297–309,Apr.
2011.
[10] J. Lew and S.-M. Moon, “A simple active damping control for
compliant base manipulators,” IEEE/ASME Trans. Mechatronics, vol. 6,
no. 3,
pp. 305–310, Sep. 2001.
[11] G. P. Starr, “Swing-free transport of suspended objects with a
athcontrolled robot manipulator,” J. Dyn. Syst., Meas. Control, vol. 107,
pp. 97–100, 1985.
[12] D. Strip, “Swing-free transport of suspended objects:Ageneral
treatment,”IEEE Trans. Robot. Autom., vol. 5, no. 2, pp. 234–236, Apr.
1989.
[13] N. C. Singer and W. P. Seering, “Preshaping command inputs to
reduce system vibration,” J. Dyn. Syst., Meas., Control, vol. 112, pp. 76–82,
1990.
[14] B. K. Kim, S. Park,W. K. Chung, and Y. Youm, “Robust controller
design for PTP motion of vertical xy positioning systems with a flexible
beam,” IEEE/ASME Trans. Mechatronics, vol. 8, no. 1, pp. 99–110,Mar.
2003.
[15] K. Sorensen, W. Singhose, and S. Dickerson, “A controller enabling
precise positioning and sway reduction in bridge and gantry cranes,”
Control Eng. Practice, vol. 15, no. 7, pp. 825–837, 2007.
[16] Q. H. Ngo and K.-S. Hong, “Sliding-mode antisway control of an
offshore container crane,” IEEE/ASME Trans. Mechatronics, vol. 17, no.
2,pp. 201–209, Apr. 2012.
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