research stations

Fig. 1. A test rig for experimental identification of dynamic properties of pneumatic springs.

It is primarily a didactic test rig. It consists of two platforms that can move along common vertical guides. The lower platform simulates the unsprung mass of the vehicle and the upper sprung mass of the vehicle. Between the upper and lower platforms, there is an air spring which can be connected to an additional rigid air reservoir. It is possible to smoothly regulate the throttling of the gas flow between the spring and the additional tank. The air spring models the suspension of the vehicle. The movement of the lower platform of the station is forced by a hydraulic cylinder powered by a pump through two proportional valves. The work of proportional valves is directly supervised by a microcontroller. The experimenter can use the digital control panel to set the desired amplitude and frequency of the hydraulic actuator movement. The movement of the hydraulic cylinder simulates the forces from the ground acting directly on the unsprung mass of the vehicle. The weight of the upper platform of the stand can be varied from 25 kg to 200 kg. During the tests on the rig, it is possible to record temporary: vertical deformation of the air spring, gas pressure in the air spring, force transmitted by the air spring, and the position of the actuator forcing the movement of the lower platform of the test stand.

The rig was also adapted for the experimental identification of friction in hydraulic cylinders. The adaptation consisted mainly in the addition of two sensors for measuring oil pressure in the chambers of the hydraulic cylinder and the development of the control software. In this regard, the presented position is used for scientific and research work.

The test rig was created as a result of the cooperation of the Department (prof. dr hab. eng. Piotr Dudziński) with the Intertractor company. It has been designed as a single, full-size chassis with an elastomer track and is equipped with a hydrostatic drive system and a tensioning system with adjustable tensioning force. The rig has a unique – to global scale – hybrid drive, enabling both frictional and contouring power transmission between the drive wheel and the track.

The control system enables programming of basic operating parameters and device operations – both in automatic and semi-automatic mode. The implemented measuring system allows the measurement of the most important operating parameters (driving torque, tensioning force, and rotational speed of the driving and tensioning wheels). 

The rig enables to study the drive transmission process between the drive wheel and the elastomer track with the use of various friction linings of the drive wheel, with a wide range of operational loads (drive torque up to 30 kNm, tension force up to 200 kN, driving speed up to 10 m/s).

The innovative demonstrator with elastomer tracks for energy consumption testing of traffic includes the IHIMER CARRY 107 transporter equipped with an adaptive chassis. The research facility is used to study the movement resistance of tracked vehicles depending on the design and operational parameters, with particular emphasis on the most energy-consuming spot and pivot turning maneuver.

The design of the tracked undercarriage enables the change of the protrusion of individual road rollers and, consequently, the distribution of normal pressure under the tracked string. An additional advantage of the vehicle is the ability to control the tension of the tracks and their offset.

Tracked undercarriage measuring systems enable continuous measurement and recording of lateral and normal forces on each of the support rollers; track tension forces; torque on the drive wheels and their rotational speed. The simultaneous recording of signals from 22 measuring transducers is possible thanks to the QuantumX HBM charge amplifiers.

The test rig has been developed mainly for the purpose of the experimental tests on the motion resistance of road wheels for tracked vehicles. It can be adapted to test the vast majority of the state-of-the-art road wheels whose overall width does not exceed 550 mm. The investigated wheels might be subjected to a vertical load of 0 to 4 kN and they can be tested in various load conditions, including the pure rolling case with uniform and non-uniform pressure distribution in the interface between the road wheel and the track surface as well as the conditions where the guide flanges of the wheel slide against the guide lugs of the track. The test rig features a special measurement plate with integrated load cells, so that three reaction force components acting on the investigated wheel are determined during every experiment. Namely, the vertical load, the lateral reaction force and the rolling resistance are simultaneously measured. The measurement signals are usually recorded by means of a laboratory grade data acquisition system QuantumX by Hottinger Baldwin Messtechnik GmbH. The rig can be also adapted to carry out quasi-static loading tests where the stiffness and damping characteristics of a road wheel coupled with a rubber track can be determined.

The rig has been developed for the purpose of determining of the resistance arising from bending of reinforced rubber belts, including rubber tracks and conveyor belts. The experiments are carried out using 120 – 130 mm wide samples of rubber belts. During the tests the samples are being wrapped around a pulley with a constant diameter. The rig is currently fitted with three ready-to-use interchangeable pulleys with a 630 mm, 800 mm and 1000 mm diameter, however, it might generally adopt a pulley with any other diameter smaller than 1400 mm. The tests are carried out at strictly controlled sample tension and linear velocity which can be adjusted between 0 – 75 kN/m and 0 – 50 mm/s, respectively (please note that the tension is expressed as a unit force per sample width). Apart from the tension and linear velocity of the sample, the angular position of the pulley is measured during the experiments. Consequently, bending resistance for virtually any cross section of the sample belt can be determined. Thus, the rig can be used to investigate the bending resistance of the belts with variable thickness or non-homogeneous internal structure.

Mechatronic tracked vehicle for rope service and transport - 1.

The vehicle, designed as part of the N R10 0011 10 development project can act as a carrier for equipment for diagnostics and maintenance of steel ropes – e.g., guy ropes of building structures (bridges, radiotelegraph masts, high chimneys), power lines, etc. 

In addition, it can be used for cable transport in hard-to-reach places, e.g., in the mountains, above the surface of water reservoirs, in fjords. Among other solutions of this type, it is distinguished by exceptionally high mobility. It can move on inclined at any angle, even vertically oriented ropes covered with a layer of preservative lubricant. High mobility is ensured by the construction of elastomer tracks, made of a material with a high coefficient of coupling with the rope. The vehicle weight of approximately 30 kg can be increased by the weight of one or more diagnostic devices (cameras, magnetic heads) or rope maintenance devices (removing and applying grease) without affecting mobility.

The vehicle may be adapted to run on ropes with a diameter in the range of 16 … 60 mm. The maximum speed is 1 m/s. The vehicle registered as an invention was awarded a gold medal at the 61st International Fairs for Invention, Scientific Research in New Techniques BRUSSELS INNOVA 2012 in Brussels and the award of the Lower Silesian Master of Technology for 2012.

Mechatroniczny pojazd linowy o adaptacyjnej mobilności do serwisowania cięgien linowych i transportu specjalnego - 1.

The process of frictional coupling of elastomers, e.g., rubber, significantly differs from the classical friction process of rigid bodies, e.g., metals, wood, etc. The unique test rig enables the experimental identification of the coupling process of elastomeric elements with any substrate. For example, thanks to the synergy of the knowledge of the creators – Piotr Dudziński and Adam Konieczny, and above all, experimental research on this device, an innovative mechatronic rope vehicle with adaptive mobility was developed. This vehicle achieves such a high coupling of the tracks with the rope, in particular covered with preservative grease, that the vehicle with a standard load can run on any inclined steel rope – even vertical, which at present is not offered by well-known manufacturers of rope vehicles in the world.

The rig is designed to test tire wheels with outer diameters smaller than 72 cm. 

It allows to determine the value of such physical quantities as: 

  • the quasi-static radial stiffness of the tire and the associated relative damping,
  • the quasi-static tire circumferential stiffness and the associated relative damping,
  • the quasi-static tire lateral stiffness and the associated relative damping,
  • the radial stiffness of the rotating tire,
  • tire skid. 

During the tests, the deformations of the tire were measured using transformer inductive transducers.

Additionally, the normal lateral and tangential forces acting on the tire are measured by means of strain gauges placed under the plate on which the tested tire is pressed. The measurement data were recorded using the QuantumX measuring amplifier from Hottinger Baldwin Messtechnik GmbH.

The mobile platform based on the Ł220 bucket loader is used for research on the dynamics and analysis of innovative control, safety, and diagnostic systems for industrial vehicles as well as for testing new design solutions in drive systems and minimizing vibrations.

It is a unique stand in the world scale for testing different undercarriage systems, in terms of numerous operational indicators of mobile working machines, such as tipping, stability, galloping and snaking, turning resistance, maneuverability, traction properties, etc. 

A well-thought-out design makes it possible to change the type of suspension, steering system, drive train, geometry, and mass parameters of the test vehicle. As a result, one vehicle is able to resemble its chassis layout to virtually any 4-wheel industrial solution.

The possibility of remote control, programming and measurement of loads acting on important elements of the chassis system makes this fully electric stand suitable for both statics and dynamics research as well as the implementation and testing of mechatronic solutions. The facility is also the basis for research on unmanned autonomous vehicles.

The design of the vehicle was created as part of the “Diamond Grant” research grant, financed from the budget for science in 2013-2018.

The stand for testing and determining the tipping stability of mobile working machines in all directions.

The special structure of the platform enables its inclination and – by rotation – any orientation in relation to the inclination. 

The whole is complemented by measuring scales with a unique design that measure not only the reactions in the normal direction (wheel pressure on the ground) but also in tangential directions.

The original research demonstrator of a wheeled vehicle for locomotion on a ferromagnetic ground was developed and built as part of Mr. Krzysztof Szczurek’s diploma thesis on the initiative and under the supervision of prof. dr hab. eng. Piotr Dudziński.

A fully functional, remotely controlled vehicle with wheels made of neodymium magnets has the ability to move on ferromagnetic substrates of various configurations, including access to vertical walls. This vehicle has a very wide range of application possibilities as an autonomous or remotely controlled robot, for example, for the inspection of steel pipelines.

The rig consists of a manipulator of a real single-bucket mini-excavator attached to a platform simulating the excavator’s body. The platform is rotatably attached to the base. The manipulator actuators and the platform rotation hydraulic motor are controlled manually with the use of adjustment levers (13), joysticks (11), or automatically with the use of a real-time computer (14).

A soil canal is attached to the turret of the station, which allows for studying the process of interaction of the tool with the soil. To enable digging at great depths, the turret of the station was equipped with extendable legs enabling the excavator simulator to be raised up.

The position and configuration of the manipulator can be determined by: 

  • measuring the relative movements of the members by magnetostrictive position transducers (3)
  • measuring the angular positions, velocity, and acceleration of the platform by optical encoders (7) and gyroscopes (9)
  • determining the angular positions of the members by inclinometers (2), (12)

To identify the loads acting directly on the excavator’s working tool, a six-axis load transducer (1) with a temperature compensation system was installed in the place of attachment of the tool to the excavator’s arm. Oil pressure (4) and its temperature (16) are measured at selected points in the hydraulic system. The load measurement of the boom cylinder piston rod is possible thanks to the strain gauge transducer (5). Measurement of dynamic loads acting on the base (excavator’s chassis) because of movements of the manipulator and the platform (excavator’s body) is possible thanks to four force-pin transducers (8).

A stereo camera (6) has been installed in the station, which enables capturing and analyzing image frames from the working process. The operator panel (10) enables to test the interfaces of various types of excavator operator support systems. 

Purpose of the position: 

  • development of automatic weighing systems for the output transported in the bucket of a single-bucket excavator, 
  • developing systems for monitoring the tipping stability of single-bucket excavators, 
  • development of load monitoring systems acting on the tools of single-bucket excavators, 
  • development of tool positioning systems for single-bucket excavators, 
  • development of systems automating the work of single-bucket excavators, 
  • studies of the interaction processes of single-bucket excavator tools on the ground.

The rig consists mainly of a measuring device for determining the strength properties of soils for determining dynamic indicators of the interaction of mobile working machines with the ground.

The device, thanks to the appropriate geometry which eliminates the so-called scale effect, kinematics copying the studied phenomenon, and above all, thanks to the possibility of carrying out the process at high speeds, enables the experimental identification of soil strength parameters in a way that best imitates the processes taking place under the running components of vehicles.

The device has the following features: 

  • large shear area (approx. 500 cm2),
  • shear rates corresponding to those occurring between the running elements or working tools and the soil (measuring speed ranges from a few mm/s to several hundred cm/s),
  • linear motion kinematics,
  • constant force generating unit pressure for shear strength measurements,
  • avoiding pushing resistance (bulldozer effect),
  • can be used for laboratory and field tests,
  • possibility of testing in a wide range of normal loads.

The device also enables the study of the processes taking place in the ground shear zone of the glass wall of the soil reservoir, as well as the study of the influence of the shape of the caterpillar spurs on the generated traction forces.

The rig includes Avant 218 loader, four scales measuring tangential and normal forces (for each of the loader wheels), a measurement interface for loads acting on the tool, and a pile of selected rock material with the maximum dimensions of 2.5 m wide, 1.5 m long and 1.2 m high. In addition, the loader is equipped with a system for measuring the orientation of the working system.

The rig enables continuous identification of loads and ground reactions during the working process of filling the bucket, in relation to the trajectory, position and orientation of the tool in relation to the material pile and the geometry of the tool used (loader bucket). The loads acting on the working tool are broken down into three components of the force and three component moments. Measurement data were recorded using Hottinger Baldwin Messtechnik GmbH QuantumX MX840 measuring amplifier and a PC. 

Currently, the bucket loader, which is part of the station, is being modernized to enable it to work in an automatic cycle.

It is a research and teaching station designed to study the influence of the geometry of the cutting blade and selected cutting parameters on the grinding process of hard rocks. One of the ready-made knives shown in the photo or a blade made specially for a given experiment can be mounted in the holder of the rig. The station allows you to set the following parameters of the cutting process: depth of cut, type of cut (e.g., open, half-open, opening, deepening), cutting speed (7.5 ÷ 53 mm/s), the angle of deflection of the blade in relation to the axis of the cutting surface, angle of the blade (0° ÷ 39°) and the blade tilt angle.

A single experiment on the bench is carried out with a cutting path of 900 mm. For mining, an artificially manufactured material is used, which has a homogeneous internal structure, which ensures the repeatability of the measurement results. During the measurements, three components of the force and three component moments are recorded, loading the tested knife. This allows for the subsequent determination of such indicators characterizing the cutting process as: cutting resistance, energy consumption of the process, or coefficients of knife load stability.

The experimental modal analysis is carried out in order to determine the natural frequency, damping and the form of natural vibrations of the tested object. Information on the frequency of natural vibrations can be used to prevent the occurrence of resonance states already at the construction stage, or in the case of an already operated object, to introduce structural changes in the tested object or vibration isolation.

Determining the form of vibrations for a given frequency allows the selection of a method, e.g. change of stiffness, introduction of damping and the place where it should be applied to minimize vibrations. Determining the damping for an object or structure allows to obtain parameters necessary to describe the dynamics of a given system.

Depending on the nature of the tested object and its scale, different excitation methods are used. Figure 1a shows the modal hammer used in the measurements. Fig.1b shows an electrodynamic exciter that allows to generate various types of excitation signals, ie: sinusoidal, random, noise, sweep sine signals and pulse signals. The signal generator and the measurement data acquisition system are located on the measuring computer (Fig. 2). An example of a measuring system for modal analysis of the hydraulic power pack is shown in Fig. 3. Fig. 4 shows an example of the result of the conducted modal analysis – the impulse response of the system (FRF – Frequency Response Function).

The scheme of the test rig is shown in Figure 1. Pressure (11) and pressure pulsation (5) are measured at the outlet of the pump motor assembly (1, 2). The flow rate is measured with a flow meter (8). The proportional relief valve (7) is used to change the operating pressure of the pump. The safety valve (6) limits the maximum pressure in the system. Electric motor speed control allows the system flow rate to be controlled. The filter (9) and cooler (10) are on the discharge side. Figure 21 shows the view of the test rig. Experimental data was collected and analyzed in LabView. The stand is equipped with a torque meter and a sensor for measuring the rotational speed. It is possible to determine volumetric, hydraulic-mechanical and total efficiency of pumps.

The rig is used to study the influence of the elastic bond in the drive system on the operation of this system, as well as to test the engine start-up. It consists of: 

  • Ring induction motor, which is the object of research. 
  • A set of loads in the form of inertia elements, brakes, and springs. The stand is also equipped with a second induction motor, which can act as an additional load in the system.
  • Measuring elements such as a strain gauge mounted between the motor shaft and one of the springs – it allows the load of the tested motor to be measured.
  • A system of slip rings and brushes to receive signals from the rotating system.
  • An amplifier and measuring computer for the acquisition and analysis of experimental data. 

The station can be configured in various ways, connecting its successive parts through couplings or with the use of elastic bonds. Therig is powered from the control cabinet via an inverter. Moreover, a starter is attached to the motor under test, which enables the addition of additional resistance to the rotor circuit.

The demonstrator of a crane and transport machine on a rail chassis (gantry crane) is an experimental object with the following parameters:

  • lifting capacity Q = 3,2 t; 
  • range L = 5,17 m;
  • lifting speed Vp = 0,8-5,0 m/min;
  • hoist travel speed Vjw = 2,2-22,0 m/min;
  • traveling speed of the crane Vjs = 6,0-60,0 m/min.

The overhead crane is equipped with inverter drives of working movement mechanism. Control is carried out manually (by radio) or in an automated manner (by a properly programmed PLC). The installed multichannel real-time acquisition system of analog and digital measurement signals simultaneously from 7 measurement points enables the recording of loads and deformations (stresses) of the crane’s load-bearing structure or its driving mechanisms.

The experimental crane allows, above all, to: 

  • testing of reloading processes and crane cycles in terms of their efficiency and energy consumption with various control methods (manual or automatic) in logistics material flow systems;
  • test of various methods of controlling the working movements of cranes in simulated conditions of their operation, characteristic for the use of cranes with work intensity groups up to A5 according to PN-ISO4301;
  • software testing of inverter hoist drives, also in any simulated operating conditions;
  • identification of loads of load-carrying structures and crane mechanisms in simulated operating conditions.

The teaching post was created as a result of cooperation between the Department and the HAK company in Wroclaw. It has been equipped with, among others, in the inverter rotation drive and the boom trolley, allowing for the determination of its temporary operating parameters.

The extensive control system of the pillar crane allows you to control the working movements using: a standard control pendant, a separate operator panel, PLC controller, and a microprocessor control unit (designed and made in the Department), which enable to work in the learning mode and repeat the previously set cycle and its optimization (by speeding up or slowing down the working movements).

The station has position sensors for individual components and strain gauge systems, allowing it to determine the stresses at key points of the superstructure. Capacity 500 kg, working area with a radius of 3.5 meters. It is possible to increase the working arm.

An experimental laboratory stand based on a jib crane for drive, control system and support structure tests