<p>This is a final thesis done at BT, considering one of their forklift truck models called Reflex. The first part of this report is about a preliminary investigation investigating what kind of diagnostic systems BTwants to use, and also which demands there are to meet all expectations on such system. Secondly a diagnostic system, which will show if the drive wheel is worn out, will be presented. </p><p>In the preliminary investigation, two kinds of diagnostic systems were mentioned. These were Model based diagnosis and Predictive analysis. Model based diagnosis is based on measurements made by sensors at the truck, while predictive analysis is based more on statistics and retrieved data about the lifetime of a truck in specific environments. </p><p>The diagnosis system for the drive wheel is based on a model made in Matlab's Simulink. Due to poor documentation, rough simplifications in the model have been made. However, one can still see the differences of principle. </p><p>The main thought was detecting a difference in the lowest torque level from the engine, varying the diameter of the drive wheel. By measurements made directly at the truck, different torques could be observed with varying diameter of the drive wheel, varying load on the truck and varying friction in the gearbox. Using hypothesis tests, it is possible to say whether the drive wheel is worn out or not. </p><p>Results show that if the drive wheel diameter is reduced by 25 mm, torque is reduced by 7% and if the drive wheel diameter is reduced as much as 50 mm, a torque reduction of 11% would be achieved.</p>

<p>The graduation essay has been carried out in co-operation with Kalmar Industries in Lidhult, Sweden. The purpose of our essay was to develop a complete construction solution on a hoist that could lift a laying wheel, lift it up and then turn it 90 degrees. After that the wheel shall be placed in a special holder.</p><p>The background of the essay is a record of reports of damage wheels when they been incorrect lifted with a forklift. The hoist shall be used together with the same forklifts that manage the wheels today. </p><p>Together with our instructor at Kalmar Industries we developed a requirement specification and from that we got free hands.</p><p>However this was not the main task from the beginning, then a simular hoist should be develop but used directly in the assembly workshop without using a forklift.</p><p>We started to find principle solutions that later was evaluated against the requirement specification. The best proposals were analyzed by hand and in Catia V5: s FEM-module.</p><p>After a couple of bettering proposal it resulted in a tenable solution. </p><p>Drawings, component specification and a risk analyze was made to finally have a complete solution.</p><p>Kalmar Industries decided to order material and manufacture the construction. The benefits with our construction compared to the daily solution are decreased risk of person injury, equipment-, and wheel damage. Our essay resulted in a complete construction ready to use.</p>

Long-haul truck drivers are absent from their families for prolonged periods of time. This paper examines the methods trucking families use to remain connected given such absences. Interviews with ten women married to long-haul truck drivers underwent qualitative analysis. Initially, personal profiles were developed to illustrate life experiences of the women. While the trucking industry set the context, the families decided how to cope with the lifestyle. Patterns of coping strategies developed by the families were described by the women. Coping strategies did not result from the efforts of one individual. All family members contributed to it in a dynamic process. One instrumental source of support was the driver's trucking company. Support systems instrumental in helping families utilize coping mechanisms were identified. Women used ambivalent thought to resolve negative emotions. In addition, an environmental analysis that compared the homes of the women and the homes of non-truckers was conducted to determine whether trucking women's homes reflected their lifestyle and attitudes toward their husband's absence. The trucking family engages in an atypical lifestyle, yet their issues are similar to those experienced by families whose husbands and fathers are home every night. Trucking families continually seek to find methods that allow them to think of themselves as normative. / Graduation date: 1999

Professional truck drivers are highly exposed to fatigue and work related injuries. Truck drivers are common victims of musculoskeletal disorders, frequently suffering from pain symptoms particularly in the neck, shoulder and lower back. This situation is believed to be a contributor to the high absenteeism in this job category. A high percentage of this problem is due to the adoption of an unhealthy driving posture resulting from inappropriate seat design. This incorrect and poor design is owing to the insufficient and obsolete anthropometrical data which has been used for decades for arranging and positioning components in the driver environment. The main objective of the present study was to create and construct a mathematical model which clarifies and predicts the drivers’ comfortable sitting posture and position. It was hypothesized that the length and height characteristics of some body segments as well as the body weight and waist circumference of the driver have a great impact on the selection of a specific sitting posture. The steering wheel positions as well as the pedal/floor locations were hypothesized to be highly correlated to the driver’s selected posture and the corresponding comfort. The effect of the seat position on posture selection and related comfort assessments constituted the other hypothesis of the study which received extra attention. A laboratory experiment on a Scania truck cab mock-up was conducted. The seat track travel along a vertical as well as horizontal forward-backward path was obtained by mounting the seat on the motorized rigid frame which allowed unrestricted vertical and fore-aft travel. The seat cushion angle and backrest angle were adjusted by pivoting the entire seat and backrest around a lateral axis and independently. The pedal components were mounted on a motorized platform, thus allowing unrestricted fore-aft and height travel without any changes in the pedal angles. The steering wheel was mounted on the instrument panel by two independent pneumatic axes which allowed a wide range of adjustments including tilting and moving along the sagittal plane for adjusting the height and distance. The test plan called for 55 international highly experienced heavy truck drivers. The drivers were recruited to span a large range of body weight and stature, in particular to ensure adequate representation of both the extreme as well as the normal group of drivers. The drivers filled in a general information questionnaire before undergoing the anthropometrical measurements and thereafter the test trials. The experiment contained a subset of test conditions with five different trials using random selection sampling procedure. Drivers were asked to adjust the components in a wide range of trajectory according to a written protocol. A sparse set of threedimensional body landmark locations and the corresponding comfort assessments were recorded. As the main part of the result, the mathematical models using multiple regression analyses on selected body landmarks as well as anthropometrical measures were developed which proposed a linear correlation between parameters. The differences between the observed data and the corresponding predicted data using the model were found to be minimal and almost dispensable. Additionally, the drivers preferred to sit in the rearmost position and at a rather high level relative to the rest of the available and adjustable area. Considering the normal adjustable seat area of the cab, only a very small part of the observed Hpoint data lies within this area while a large remaining amount of data lies outside of it. Moreover, the difference between the observation (plotted H-point data) and the neutral H-point was found to be significant. Furthermore, and since some of the data lies almost on the border of the adjustable area, it may indicate a reasonable tendency for even more seat adjustment in the backward direction. A conceptual model consisting of four different parameters was developed and presented in the end. These parameters of the model suggest being as key factors which play a central role on process of decision making regarding the selection of a desirable sitting posture. Any eventual modifications and adjustments for elimination or minimizing discrepancies, biases or obscured factors affecting the quality of the mathematical model would be a case for future study. The investigation of a complete assessment of comfort should be supplemented with an analysis of how many truck drivers are satisfied with the comfort in the end. / QC 20100824

The purpose of this thesis is to, on Volvo Truck’s account, look at a new concept for the construction ingress used on construction vehicles which have a higher ground clearance than ordinary trucks. The high ground clearance makes it hard for the driver to reach the first instep and therefore a construction ingress is assembled below the stationary insteps. It is designed in a way that avoids damage if colliding with objects. The present construction ingress used is too expensive, too complex and a bit unsteady to climb on. There is also a new construction vehicle being developed and the old ingress might not fit the new truck. The concept generation is carried out using systematic concept development. There are many demands and requests for the ingress and these are summarized in a design criterion list. All wished-for properties can not be fulfilled for the simplest ingress designs since they conflict with each other, for example flexibility and stability. The concepts that are generated are evaluated and selected through different matrices until one concept is found to be the most promising. Different designs of this concept are discussed and one is chosen as the most suitable. The chosen concept design is already used by at least two competitors and that confirms its suitability. The detailed design presented is only a suggestion for a new construction ingress. Before manufacturing the design needs to be analysed more accurately and the strength, material and cost need to be optimized. The analyses made in the project only show that the design is realistic and that it is worth further work. The final design is promising since it is stable to use, consists of only a few simple parts and will be cheap to manufacture.

This master thesisinvestigates the possibilities to implement a digital filter for wire guidancein a truck. The analog circuits in the truck, today, are analyzed to understandtheir signal processing. The component MAX261 is especially interesting and itis analyzed in a special Section to make sure that all needed details, todevelop a digital filter, are available. When all theoretical calculation wasfinished, all the circuits were simulated to make sure that the calculationsare correct.   The digital filter is based onan analog filter which is expensive and not so easy to purchase. A requirementspecification was developed by analysis of the properties of the analog filterand how it is currently used. The analog filter is a part of a chain of analogsignal processing which mostly can be performed digitally instead.   The special type of the analogfilter makes the requirements, on the digital filter, very tough and anextensive analysis of digital filter structures was performed in order to finda suitable filter. The digital filter is of WDF (Wave Digital Filter)-type andit is very special, because it has two variable coefficients, one for thesteepness and one for the center frequency. The digital filter consists of anumber of first order filters, because a higher order filter with desiredproperties has coefficient values that are large which makes the stabilityproperties worse.   The best type ofimplementation of this filter and the signal processing are also analyzed.Finally, a prototype was developed on a development board where the maincomponent is a DSP (Digital Signal Processor). The program for the prototype iswritten in C-code and the performance of the system was verified by differenttests and measurements.

Livsmedelsdistributören Dagab håller på att lägga om sin leveransstruktur för sina olika lager i Sverige. Omläggningen leder till att en annan typ av varor kommer att hanteras och förmodligen kommer de nya varorna kräva större yta då de ställs upp inför leverans. Dagab har bett oss att undersöka om det går att effektivisera flödet av pallarna på lagret i Jordbro. Då vi ansåg att simulering skulle vara ett bra verktyg för att undersöka detta bestämde vi oss för att i rikta in examensarbetet mot att bygga en simuleringsmodell. Genom att införa förändringar i en modell istället för i ett verkligt system kan konsekvenser och tendenser undersökas i modellen istället för i ett riktigt system. Att göra förändringar i ett riktigt system kan vara både kostsamt och riskabelt om det inte i förväg går att veta att förändringarna leder till besparingar eller effektivisering. Vid simulering måste verkligheten representeras av en modell, för att det ska vara möjligt att genomföra ett sådant arbete måste en del antaganden införas. Målet är att förenklingarna inte på något sätt ska försämra modellens möjlighet att representera verkligheten. Då modellen var klar implementerades de olika förändringarna och resultaten granskades och utvärderades. Simuleringen visar att om enkla åtgärder vidtas kan Dagab öka sitt inflöde med närmare 50 procent alternativt minska antalet lastbilar för utleveranser. Våra föreslagna förändringar innebär att staplingsprocessen ska förbättras. Redan innan arbetet började kände vi intuitivt att en effektivare stapling skulle leda till kraftiga förbättringar på lagret. När arbetet nu slutförts har detta styrkts och relevanta siffror, vilka beskriver förbättringarna, har tagits fram. Med de här siffrorna kan ekonomiska beräkningar enklare göras och det skulle bli lättare för beslutsfattarna på Dagab att fatta beslut angående förslagen vi lämnat.

This is a final thesis done at BT, considering one of their forklift truck models called Reflex. The first part of this report is about a preliminary investigation investigating what kind of diagnostic systems BTwants to use, and also which demands there are to meet all expectations on such system. Secondly a diagnostic system, which will show if the drive wheel is worn out, will be presented. In the preliminary investigation, two kinds of diagnostic systems were mentioned. These were Model based diagnosis and Predictive analysis. Model based diagnosis is based on measurements made by sensors at the truck, while predictive analysis is based more on statistics and retrieved data about the lifetime of a truck in specific environments. The diagnosis system for the drive wheel is based on a model made in Matlab's Simulink. Due to poor documentation, rough simplifications in the model have been made. However, one can still see the differences of principle. The main thought was detecting a difference in the lowest torque level from the engine, varying the diameter of the drive wheel. By measurements made directly at the truck, different torques could be observed with varying diameter of the drive wheel, varying load on the truck and varying friction in the gearbox. Using hypothesis tests, it is possible to say whether the drive wheel is worn out or not. Results show that if the drive wheel diameter is reduced by 25 mm, torque is reduced by 7% and if the drive wheel diameter is reduced as much as 50 mm, a torque reduction of 11% would be achieved.

The graduation essay has been carried out in co-operation with Kalmar Industries in Lidhult, Sweden. The purpose of our essay was to develop a complete construction solution on a hoist that could lift a laying wheel, lift it up and then turn it 90 degrees. After that the wheel shall be placed in a special holder. The background of the essay is a record of reports of damage wheels when they been incorrect lifted with a forklift. The hoist shall be used together with the same forklifts that manage the wheels today. Together with our instructor at Kalmar Industries we developed a requirement specification and from that we got free hands. However this was not the main task from the beginning, then a simular hoist should be develop but used directly in the assembly workshop without using a forklift. We started to find principle solutions that later was evaluated against the requirement specification. The best proposals were analyzed by hand and in Catia V5: s FEM-module. After a couple of bettering proposal it resulted in a tenable solution. Drawings, component specification and a risk analyze was made to finally have a complete solution. Kalmar Industries decided to order material and manufacture the construction. The benefits with our construction compared to the daily solution are decreased risk of person injury, equipment-, and wheel damage. Our essay resulted in a complete construction ready to use.

The currently low requirements on sound emissions for industrial trucks are expected to be raised in the near future. The company Kalmar Industries AB, which develop, produce and market industrial trucks, want to improve their truck silencers as a precaution to the future harder restrictions and also to improve their competitiveness. The sound emission produced by a vehicle depends on type and range of application it is designed for but the dominant part of the sound is usually produced by the engine and silencer. A new measuring method is developed for studying sound emanating through the silencer system. The analysis of the measurement data establishes that the silencers are not working well. The simulations made with SIDLAB, which is a computer programme for calculating the propagation of sound in ducts, confirms that the silencers are inefficient and that they are simply too small. A simulation which implements a parallel resonator in the main silencer shows that it is possible to make great improvements in reducing the noise from the truck as well as meeting requirements on space. Mathematical modelling based on linearity and one-dimensional interaction between the silencer elementsis advantageous and gives very good results when understanding, analysing and simulating the silencer. The simulation tool SIDLAB works well and saves a lot of time by its fast modelling and easy interface.