University of Central Lancashire: Crane LMI System Detailed Report

This report provides a comprehensive analysis of a Crane LMI (Load Moment Indicator) system, focusing on its various components and their functionalities. The report begins with an overview of LMI systems in cranes, emphasizing their importance in measuring loads and preventing structural failures. It then delves into the specific sensor systems within the LMI, including the angle sensor, angle and length transmitter, wind speed sensor, load plate system, and anti-two-block sensor. The report further explores the LMI system's front panel and a measurement system block diagram. A significant portion of the report is dedicated to experimental critical analysis, particularly focusing on the anti-two-block sensor and wind speed sensor, utilizing NI DAQ and NI LabVIEW software for analysis. The analysis compares the results obtained from both software to highlight the differences in settings. The report also covers the next phases of development and concludes with a summary of the findings and a list of references. The assignment was part of the Sensors, Instrumentation & Control module (MP4706) at the University of Central Lancashire.

CRANE LMI SYSTEM FOR GLOBAL TECHNOLOGIES
Student Name
Professor’s Name
Date

Table of Contents
LMI SYSTEM OVERVIEW........................................................................................................................3
LMI systems in Cranes.................................................................................................................................4
Angle sensor system.................................................................................................................................4
Angle and length transmitter system........................................................................................................4
Wind speed sensor....................................................................................................................................5
Load plate system.....................................................................................................................................5
Anti-two Block sensor system..................................................................................................................5
LMI SYSTEM FRONT PANEL..................................................................................................................6
A MEASUREMENT SYSTEM BLOCK DIAGRAM................................................................................7
EXPERIMENTAL CRITICAL ANALYSIS................................................................................................7
The Anti-Two-Block Sensor System........................................................................................................7
Wind Speed Sensor..................................................................................................................................8
SIGNAL CONDITIONING ELEMENTS EVALUATION.........................................................................9
NEXT PHASES OF DEVELOPMENT.......................................................................................................9
CONCLUSION..........................................................................................................................................11
References.............................................................................................................................................11

LMI SYSTEM OVERVIEW
The hydraulic cranes are the cranes which makes use of the Loan Moment Indicator. In cranes,
the Loan Moment Indicator is employed in reading the measurement value of the loads by the use
of the transducers. The transducers use pressure in its operation. They also read the pressure of
the cylinder of the lift in cranes (Anon n.d). The Loan Moment Indicator is very much important
in cranes; it is used in order to know the way the load is lifted in cranes. By the use of this
particular mechanism, it is possible for the operator of the load to have knowledge of how much
load is being lifted by the crane as well as being able to know if the loads which are lifted by the
crane has been exceeded. In basic knowledge, the LMI is used in measurement of the moment
and bearing force in the arms of the cranes when the crane is in operation. When the lifting
capacity exceeds the maximum set, then the arm of the crane is designed in such a way that ir can
fail in several different stages; this includes mechanical failure as well as the structural failure
among others (Cao and Zheng, 2013). The functioning and the indication of the LMI is supposed
to be closely checked and tracked by the crane operator, as it signals the operator especially when
the limit of the load has been exceeded or is approaching in order to prevent the arm of the crane
from failing.
In the calculation of the overall load of the crane, the boom weight is also included as part of the
calculation. The LMI system therefore is main functioned at calculating the elements effects
which alters the overall weight of the load which includes the wind, as well as the ice which is
added in the capacity of the lifting that is available (Kaitl, 2020).

LMI systems in Cranes
In cranes the LMI is made up of the Angle and length transmitter system, The load plate system,
wind speed sensor system, Angle sensor system and the Anti-two block sensor system. The above
systems are described in details in the below section;
Angle sensor system
The angle sensor system is among the most crucial and important systems in the crane Load
Moment Indicator system. With the angle sensor system, it makes it possible to measure the
position and the angle of the steering wheel being used by the operator of the crane. It is also
used in rating the angle at which the steering when can turn. The angle sensor is made with a
scanning tool that is employed to provide information about the angle at which the steering when
has turned and its general position in degrees. The sensor is situated at the sensor cluster that is
placed in the steering column (Anon n.d). In order to reduce redundancy of data as well as
confirmation of information, the crane is always made up of at least two angle sensor systems.
This two systems are independent and each of them is used to provide different data. this helps
the operator of the crane to be in a position to confirm the information displayed by every sensor
system in order to be sure of the operation. The ESC system which is in the angle sensor system
is made to receive at least two signals in order to make confirmation as well as affirmation of the
exact location and angle position of the steering wheel (Patel and Patel, 2015).
Angle and length transmitter system
The angle and length transmitter system is a LMI system part of the crane which is used to
measure the angle of the cylinder and the telescoping cylinder as compared to the gravitational
force. Majorly all cranes employ the use of the angle and length transmitter system (Salánki and
Sarvajcz, 2019). By the use of this system, the cranes boom length as well as the boom angle are
measured by the system. Though the sensor system is not resistant to some other environments, in
the places where the conditions are very harsh, especially to mobile cranes which are carried to
work at different parts of in a country, the sensor system is removed. An approximation of 32 feet
cable reel is contained in the angle and length transmitter sensor system that is employed in
measuring the overall length. It also has the length of the resolution which is about 30 mm. the
accuracy of the length which is about 30 mm, the degree of resolution that is 0.2 degrees, and the
accuracy of the angle which is 0.2 degrees (Anon n.d).

Wind speed sensor
Normally, all types of cranes are designed, and manufactured in a way that it is impossible for
them to work harsh conditions like in a place of very high speed wind. This is done for the safety
of the cranes itself as well as the operator of the crane. The wind sensor therefore is fitted in the
cranes which is utilized in measuring and making determination on the safety of the place before
and during operation. When the wind speed is very high, the crane wind sensor will notify the
operator in the dashboard over the same for the operator to take necessary precautions, (Anon
n.d). The wind sensor has got a limit of the speed wind and it shall make its determination of the
condition of the place as far as wind speed is concerned. the intensity of the wind is measured,
when it goes beyond the maximum limit, the operator is able to see as the elements of the wind
speed sensor is always placed in the display dashboard for the operator of the crane to be able to
see make determination on whether to continue the operation or shalt the operation.
Load plate system
For the cranes which are utilized in loading and offloading very heavy goods and loads, the load
plate system is used. Such cranes include those used for loading and offloading steel mills, coils,
steel plates, tracks, vessels of the ocean and many other loads which are very heavy. The term
load plate refers to the loading space where the load is placed before the load is shifted to another
plate vessel. For the load plate, it is made up of the following elements (Anon n.d);
The load plate has the capability of developing a very strong force which is able to accommodate
the extended plate that is employed for loading very wide ships and loads.
The system has the capability to control very wide leg that is used for offloading and unloading
without the process slewing to happen in every cycle.
Anti-two Block sensor system
The Anti-two-block system A2B, is majorly used for warning or preventing the operator of two
block condition which is found in the crane. The two-blocking condition in cranes is a very
critical condition which involves the lower hook block of the crane is uplifted very high to an
extend of getting in contact with the parts of the boom hardware in the crane. The term A2B is
originated form the block and tackle engineering physics terminology which explains when the

pulley upper part and lower part comes into contact with one another. The two blocking condition
occurs mainly while winching up the crane, when the boom is being telescoped out, and also
when the crane is booming down (Anon n.d). With any of the above condition in action, the
lower hook of the crane therefore will draw over the upper sheave. The sensor system prevents
the crane hook block to crash against the boom head more especially when the load is lifted. In
order to keep the contact switch closed, the counterweight is normally applied. Employing the
use of the anti-two block sensor, as the hook block is raised to the upper point almost to the boom
weight, the hook will instead hit the counterweight in order to prevent it from hitting the boom
weight. The counter weight in this case will rise hence opening up the contact again. Just because
of the above very crucial functioned that is done by the sensor, the switch is supposed to be very
reliable in such a way that its need to be resistant to almost all types of weather as it exposed to
external weather conditions (Yang, Chen and Liu, 2014).
LMI SYSTEM FRONT PANEL

A MEASUREMENT SYSTEM BLOCK DIAGRAM
EXPERIMENTAL CRITICAL ANALYSIS
As the research demands that two sensor system be critically analyzed using the DAQ as well as
the NI LabVIEW software, the anti-two block sensor system and the wind speed sensor were
analyzed critically as shown below.
The Anti-Two-Block Sensor System
As discussed earlier, the Anti-two-block system A2B, is majorly used for warning or preventing
the operator of two block condition which is found in the crane. The two-blocking condition in
cranes is a very critical condition which involves the lower hook block of the crane is uplifted
very high to an extend of getting in contact with the parts of the boom hardware in the crane. The
term A2B is originated form the block and tackle engineering physics terminology which
explains when the pulley upper part and lower part comes into contact with one another
(Komnaska, 2013). The two blocking condition occurs mainly while winching up the crane, when

the boom is being telescoped out, and also when the crane is booming down. With any of the
above condition in action, the lower hook of the crane therefore will draw over the upper sheave.
The anti-two block sensor system is critically analyzed by the use of NI DAQ as well as NI
LabVIEW software. When the NI DAQ was used for the analysis, is it evident that the distance
under which the boom weight and the hook block is being monitored was set to be at around 15
inches as per the analysis. This is different from the critical analysis of the NI LabVIEW software
where the limit distance between the boom weight and the hook block of the crane was set sat 5
inches only (Komnaska, 2013). The distance which was set as seen from the NI LabVIEW
software is very close, therefore dangerous since in any case there is any slight mistake done or
maybe mechanical error or failure of the crane system, then the hook block will most likely have
to crush the boom weight at the upper side of the system. This is possible as the load that is being
offloaded or loaded by the crane can be swayed off using the wind which might close the gap
distance therefore resulting to the effect.
Wind Speed Sensor
As discussed, under normal conditions, all types of cranes are designed, and manufactured in a
way that it is impossible for them to work harsh conditions like in a place of very high speed
wind. This is done for the safety of the cranes itself as well as the operator of the crane. The wind
sensor therefore is fitted in the cranes which is utilized in measuring and making determination
on the safety of the place before and during operation. When the wind speed is very high, the
crane wind sensor will notify the operator in the dashboard over the same for the operator to take
necessary precautions (Lee, 2013).
When the NI DAQ was used for critical analysis, it is evident that the sensor is set to measure the
speed of the wind with respect to its intensity as detected from the load. When the speed of the
wind is beyond 45km/h, the sensor will detect high speed wind hence recommending the crane
operations to be halted. The NI DAQ analysis shows that the set limit of the wind is static and
unchangeable regardless of the temperature which affects the later intensity of the wind. When
the analysis was done using the NI LabVIEW software, it shows that the speed of the wind is
affected by the temperature of and atmospheric humidity. This resulted to variation of the speed

of wind limit from 45 km/h to between 43km/h to 48 km/h. This hence make the analysis on the
wind speed sensor using the NI DAQ be more accurate and sustainable for cranes operation.
SIGNAL CONDITIONING ELEMENTS EVALUATION
The conditioning of the signals is very important for the study of the LMI as they help in
understanding the measurement system being used in crane LMI system. Understanding the
signal conditioning of each and every type of measurement is very much important. Therefore,
the below table shows the signal conditioning;
Amplification Attenuation CJC Filtering Excitation Isolation
Accelerometer Yes No No Yes Yes Yes
Strain Gauge Yes No No Yes Yes Yes
RTD Yes No No Yes Yes Yes
Thermistor Yes No No Yes Yes Yes
Load and
pressure
Yes No No Yes Yes Yes
Thermocouple Yes Yes No Yes Yes Yes
NEXT PHASES OF DEVELOPMENT
A. Redesigning and development of a low cost sensor system and controllers.
The current cost of designing and development of the LMI system is very high. This
makes the total cost of the crane to be very high. Designing and developing of the most
modern controllers and sensors will be very vital and important as it will make the overall
system to be affordable to everyone (Tumari et al. 2012).
B. Employment of Wireless and wired transmission instead of the current mechanical
method.

The cranes systems are currently using mechanical methods of transmitting information to
the LMI dashboard system from the operation to be in apposition to view. This method is
very slow as compared to the technologies which are currently in use. Using either wired
or wireless more of data and signal transmission is supposed to be the next level of
designing he LMI sensor system which will in turn be very fast and low cost.
C. Proposal for the next phases of development to include the use of the Internet of Things
Internet of things is the current technology which is moving the world to the next phase of
technology which others refers to it as the ultimate of technology. This same technology
can also be employed in the cranes where the crane dashboard will be stored in the clouds
and accessed remotes at any point or location.

CONCLUSION
To conclude, the NI DAQ analysis is seen to be more accurate as compared to the NI LabView
software analysis. It is therefore recommended that NI DAQ analysis be employed in preview
and during the process of designing and development of the crane LMI system. The next
generation technology also be used in order to modernize the system more and also making it
cheaper to acquire the Sensor system.
References
Anon, (n.d.). Crane System Types - LMI - RCI - Scale and Control Inc.. [online] Available at:
https://www.scaleandcontrol.com/crane-lmi-rci.html [Accessed 2019].
Anon, (n.d.). Cranesmart Systems - Crane Safety. Made Simple.. [online] Available at:
http://cranesmart.com/ [Accessed 2019].
Anon, (n.d.). How to run a crane computer lmi - YouTube. [online] Available at:
https://www.youtube.com/watch?v=uygeCH6_dw8 [Accessed 2019].
Anon, (n.d.). The Cranesmart LMI System - Cranesmart Systems - Crane .... [online] Available
at: http://cranesmart.com/wp-content/uploads/2017/01/900-Cranesmart-LMI-Rev-11-FEB-4.-
2015.pdf [Accessed 2019].
Cao, L. and Zheng, M., (2013). Lifting Capacity Detection System of Tower Crane Based on
LabVIEW. Applied Mechanics and Materials, 380-384, pp.860-865.
Kaitl, K., (2020). The Development of Image Capturing System Applied in Shooting Simulator
using LabVIEW. WSEAS TRANSACTIONS ON SIGNAL PROCESSING, 16.
Komnaska, M. (2013). Crane control system design via lmi-approach. Electronics and Control
Systems, 3(37).
Lee, M. (2013). Design of a Robust Track-Following System Using Genetic Algorithm and LMI
Approach. Korea Institute of Information Technology Review, 11(8).

Patel, H. and Patel, J., (2015). LabVIEW based ‘nonlintool’ for analysis and design of nonlinear
control system. Computer Applications in Engineering Education, 24(2), pp.195-201.
Salánki, D. and Sarvajcz, K., (2019). Development of a Gait Recognition System in NI
LabVIEW Programming Language. Műszaki Tudományos Közlemények, 11(1), pp.167-170.
Tumari, M., Saealal, M., Wahab, Y. and Ghazali, M. (2012). H-Infinity Controller with LMI
Region Schemes for a Lab-Scale Rotary Pendulum Crane System. International Journal of
Signal System Control and Engineering Application, 5(1), pp.14-20.
Yang, Y., Chen, X. and Liu, Q., (2014). Development of GIS PD Location System Based on
LabVIEW. Advanced Materials Research, 1044-1045, pp.1469-1472.