On-Board Electronic Control Systems of Future Automated Heavy Machinery

The level of automation and wireless communication has increased in heavy machinery recently. This requires utilizing new devices and communication solutions in heavy machinery applications which involve demanding operating conditions and challenging life-cycle management. Therefore, the applied devices have to be robust and hardware architectures flexible, consisting of generic modules. In research and development projects devices that have various communication interfaces and insufficient mechanical and electrical robustness need to be applied. Although this thesis has its main focus on machines utilized as research platforms, many of the challenges are similar with commercial machines.The applicability of typical solutions for data transfer is discussed. Controller area network with a standardized higher level protocol is proposed to be applied where data signalling rates above 1 Mb/s are not required. The main benefits are the availability of robust, generic devices and well-established software tools for configuration management. Ethernet can be utilized to network equipment with high data rates, typically used for perception. Although deterministic industrial Ethernet protocols would fulfil most requirements, the conventional internet protocol suite is likely to be applied due to device availability.Sometimes sensors and other devices without a suitable communication interface need to be applied. In addition, device-related real-time processing or accurate synchronization of hardware signals may be required. A small circuit board with a microcontroller can be utilized as a generic embedded module for building robust, small and cost-efficient prototype devices that have a controller area network interface. Although various microcontroller boards are commercially available, designing one for heavy machinery applications, in particular, has benefits in robustness, size, interfaces, and flexible software development. The design of such a generic embedded module is presented.The device-specific challenges of building an automated machine are discussed. Unexpected switch-off of embedded computers has to be prevented by the control system to avoid file system errors. Moreover, the control system has to protect the batteries against deep discharge when the engine is not running. With many devices, protective enclosures with heating or cooling are required.The electronic control systems of two automated machines utilized as research platforms are presented and discussed as examples. The hardware architectures of the control systems are presented, following the proposed communication solutions as far as is feasible. Several applications of the generic embedded module within the control systems are described. Several research topics have been covered utilizing the automated machines. In this thesis, a cost-efficient operator-assisting functionality of an excavator is presented and discussed in detail.The results of this thesis give not only research institutes but also machine manufacturers and their subcontractors an opportunity to streamline the prototyping of automated heavy machinery

Development and Implementation of the Control System for an Autonomous Choke Valve for Downhole Flow and Pressure Control

Drilling operations in the oil and gas industry calls for tight control of well pressure. A drilling fluid is used to control the pressure in the well, remove cuttings, and lubricate and cool the drill bit. If the well pressure becomes either too low or too high, it can cause cave ins or fracturing of the well. When drilling operations are executed from a floating drilling rig, the drill string may move in and out of the well with the ocean waves. This will cause pressure fluctuations in the well. As of today, the downhole pressure is controlled from topside equipment, but due to the length of the drill string, significant delay makes pressure control difficult. A proposed solution to remedy this problem is to install a choke valve downhole, right above the drill bit. This choke valve and its control system has been named HeaveLock. The aim of this thesis is to make the HeaveLock autonomous, and capable of controlling the downhole pressure in a lab at NTNU. The hardware and software that makes up the HeaveLock has been carefully selected and developed with autonomous operations in mind. The software that controls the HeaveLock is designed as a concurrent real-time program. It estimates the velocity of the HeaveLock based on acceleration, and uses the estimated velocity to control flow through the choke valve. By controlling the flow, pressure attenuation can be obtained. Both the velocity estimation and flow control algorithms are based on previous work, and has been discretized and adjusted to fit the purpose of the HeaveLock. A graphical user interface for a computer has been developed to enable effortless configuration and live data acquisition. Every aspect of the HeaveLock has been tested both individually and collectively. The HeaveLock estimates velocity with good precision, and operates as intended. Unfortunately, due to the lab being occupied with other experiments, it was not possible to perform the final test in the lab within the deadline of this thesis. However, a suggestion for how such a test should be performed has been attached to this thesis. With the exception of the pressure attenuation test of the HeaveLock in the lab, all objectives of this thesis have been met. The system is ready for the final test before being used in experiments

Design and implementation of double H’-gantry manipulator for TUT microfactory concept

This Master of Science thesis depicts the mechanical design and physical implementa-tion of double H’-gantry manipulator called DOHMAN. The H’-gantry mechanism is belt driven, two dimensional positioning device in which the belt is arranged in capital “H” form, and enables one linear and one rotary movement. The Ball-Screw Spline, in addition, is mechanism that consists of Ball Screw Nut, Ball Spline Nut, and Lead Screw with screw and spline grooves that fit both nuts. This mechanism enables linear and rotary displacement along the same axis. The DOHMAN robot is made of two par-allel kinematic H’-gantry structures linked with a miniature Ball Screw-Spline mecha-nism. The resulting structure is capable of performing four degrees-of-freedom (DOF) displacements along the three Cartesian axes X, Y and Z as well as a rotation W around the Z axis. The size and the other geometries of the DOHMAN robot aim to fit into the microfactory concept (TUT-μF) developed at Tampere University of Technology. For position control and visual servoing of the robot, an additional module was de-signed and implemented. Custom design of mechanical parts along with the selection of off-the-shelf components was done for building the robot prototype. The chapters and the appendix of this thesis thoroughly explain the design decisions and the implementa-tion. During the design development a new innovative homing strategy for linear Z and angular W axes was suggested and later implemented. This innovative homing provides efficient use of space for mounting the limit switches, avoiding huge loss in the overall Z-axis movement, and significantly reduces the cabling issues in the moving structure. Besides the innovative homing, other advantages of DOHMAN are distributed actuation and homogeneous workspace. The distributed actuation decreases the overall mass of the moving structure and also reduces the cabling within the overall mechanical system. The consistency in the workspace eases the control of the robot because there are no regions to avoid while moving the end effector

Volume 1 – Symposium: Tuesday, March 8

Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Components:Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Component

Liikkuvien työkoneiden värähtelyn vaimennus painetakaisinkytkennällä

In this thesis a hydraulically driven wheel loader, which has a flexible crane mounted in front of the machine, has been under research. Flexible boom was excited with a operator given commands, which caused the system vibrate due to different sources of flexibility. The goal was to test cylinder load pressure as a estimate of boom vibrations and use it as a feedback signal to suppress the system oscillations. Therefore, a simulation of wheel loader was created, which replicates real four wheel loader located at the facilities of Laboratory of Automation and Hydraulics. The first simulator represents a traditional hydraulical system, which has proportional directional valves and variable displacement pump with load sensing functions. A simple controller with pressure feedback vibration damping was designed and tested with different scenarios. After promising results, another simulator was created, which emulates the existing wheel loader better. This experimental wheel loader, called as IHA-machine, has different directional valves and pump operating principal. For working hydraulics, a digital flow control unit was installed. As a power source, IHA-machine has a variable displacement pump-motor, which has a possibility to collect energy from hydraulic system. Updated simulation version was tested with a controller, which was able to control flow and supply pressure. Vibration damping was added to the flow controller and tested in simulator. After this, the same controller was also tested in real IHA-machine. The results showed, that load pressure as an estimate of system vibrations is a promising way to damping the oscillations that exist in the application. However, the simulation results couldn't be repeated at the same level in the real machine. The control of boom with flow in digital valve environment appeared to be a difficult task when vibration damping was implemented. Regardless, some oscillation canceling was still achieved

Modeling and experimental characterization of belt drive systems in micro-hybrid vehicles

Belt Drive Systems (BDS) constitute the traditional automotive mechanism used to power the main internal accessories (such as the alternator, water pump and air conditioning pump) taking power from the engine's crankshaft rotational motion. BDS usually work in the severe ambient conditions of the engine compartment and are subject to highly dynamic excitations coming from the crankshaft harmonics. The substitution of the traditional alternator with an electric machine, namely Belt Starter Generator (BSG), is the most promising micro-hybrid technology towards a quick and effective satisfaction of the current regulations of fuel consumption and pollutant emissions reduction. The use of a BSG leads to increased stresses in the already complex front end accessory drive. As a matter of fact, a BSG is an electrical machine able to work both as motor and as generator and defines two distinct functioning modes of the drive, namely motor and alternator modes. The relative alternation of tight and slack spans profoundly changes the functionality of the overall drive and affects its transmissions capability and efficiency, furthermore resulting in NVH (noise vibration harshness) effects that need to be carefully addressed. Traditional automatic tensioners acting on the slack span of the alternator mode application are not capable of facing the irregular stresses of a BSG-based BDS which requires the use of a tensioning device capable of keeping the belt tension inside a safe range and of preventing slippage during all the operating conditions of the drive. With this goal many solutions are currently being investigated, such as the cooperation of two tensioners one for each span, active tensioners, double arm tensioners or hydraulic tensioners. The critical issues due to the involvement of BSG in BDS require a deep study focused on the tension conditions of the belt and its influence on the overall efficiency of the system. The aim of the research described in this thesis is to obtain a defined modelling approach of belt drive systems for micro-hybrid vehicles and to validate it through extensive experimental analysis. To obtain a reliable testing environment, a dedicated full-electric test rig was designed and realized. The test rig presented in this work is capable of assuring the repeatability and accuracy of the measurements leaving aside the uncertainties deriving from the irregularities of the ICE behaviour that usually affect the experimental activities conducted on front engine accessory drives. After providing both the modelling and testing environment as assets for the analysis, several experimental activities are carried out with the goal of assessing the dynamic behaviour of belt drive systems and their efficiency, comparing the performances of different tensioning solutions, understanding the behaviour in static and dynamic conditions of a traditional automatic tensioner and one example of an omega twin arm tensioner, which is the tensioning solution most explored by the manufacturers at present. The ultimate goal of gaining a complete understanding of belt drive systems in the special case of micro-hybrid vehicles is eventually fulfilled by an experimental validation of the static and dynamic models proposed

Motion control of 3D Cartesian robots for different mechanical applications using the CoDeSys SoftMotion in PLC

LAUREA MAGISTRALEThis work involves the motion control of the Cartesian Robots for the applications like Gasketing using SoftMotion technique in PLC. The “SoftMotion” is a part of Controlled Development System (CoDeSys) and the functionality is used for realizing movements from a simple single axis CAMs to complex motions in several dimensions of the development environment. Those applications where sequence and process control or auxiliary functions play a key role alongside the motion functions are ideal for use with SoftMotion (as opposed to those that are exclusively concerned with motion functions). With the implementation of the SoftMotion technique, this work shows the economic efficiency of the system for performing the same task as the NC machine with the same level of precision, just by using the PC of a user, a drive controller and a dedicated HMI