Design of innovative solutions
Load-bearing structure of cranes
Currently designed handling equipment (UTB) must meet the requirements of the Machinery Directive and applicable standards (e.g., EUROCODE 3). Meeting these requirements is all more necessary as a large part of these devices is subject to supervision (UDT).
The Department offers services in the field of designing load-bearing structures of cranes and their additional equipment (traverses, special hangers), taking into account the requirements of the above-mentioned legal acts. We adapt the proposed solutions to the specific working conditions and the resulting limitations as well as the unusual needs of users, e.g., traverses with increased stiffness.
Wheeled and tracked undercarriages for off-road vehicles
The Department of Off-Road Machine and Vehicle Engineering (DORMVE) has a great experience in designing undercarriage systems for off-road vehicles, including the earthmoving and agricultural mobile machines. The most impressive projects developed by DORMVE in this field are as follows:
- The new generation rubber track system with a hybrid, positive/friction drive transmission, active road-wheels’ suspension and adaptive track tensioning systems (the project developed in cooperation with German companies IAMT, IBAF and Intertractor AG),
- An innovative rubber-tracked undercarriage of a mobile drill rig for operation in arctic extreme conditions (the project developed in cooperation with Canadian Cubex company),
- A heavy-duty WKPL 35/50 dump truck with a hydrostatic, four-wheel drive system (the project developed in cooperation with LEGMET, CUPRUM and REXROTH companies).
We are ready for the new challenges. We are especially looking forward to designing innovative undercarriage systems suited to the most extraordinary requirements. We thoroughly consider every aspect of our undercarriage designs to provide the vehicles with the highest performance possible. The best performance of the undercarriages designed by DORMVE is guaranteed by the knowledge based on a comprehensive literature review, including the most up-to-date technical standards and scientific papers, as well as the experience arising from the experimental tests conducted for many years using our advanced laboratory facilities. On the basis of the required load capacity and the maximum permissible pressure under the vehicle, we adopt the general concept of the vehicle, choosing between a wheeled or tracked option. Afterwards, the general concept is refined to provide a vehicle with:
- the highest roll-over stability possible,
- the smallest possible susceptibility to the snaking phenomenon,
- the highest possible energy efficiency of the undercarriage mechanisms,
- minimized energy consumption arising from the interaction between the wheels or tracks and the soft ground, including the smallest possible turning resistance,
- the smallest possible compaction and shearing damage of the ground,
- the most effective operator’s protection against the vibrations induced by the working gear or due to operation on bumpy terrain.
Apart from the holistic projects, we are open for cooperating with industrial companies and research institutes on research and development projects on selected aspects in the field of the tracked and wheeled undercarriage engineering. We are proud to constantly provide the leading Polish manufacturers of working machines, including KGHM ZANAM, with backup on optimizing the design of off-road vehicle undercarriages in terms of maximizing roll-over stability and other properties.
Solutions for off-road machine manipulators
Solutions for off-road machine manipulators using hybrid drives, aimed at recovering the kinetic energy of movement or reducing the proportion of energy that is lost due to inefficient operation of the drive source, make it possible to significantly increase the efficiency of the system. Solutions are proposed to recover some of the energy from the return movement (due to gravitational forces) so as to reduce fuel consumption in the next load (lifting) cycle. The optimisation of the boom’s performance is carried out by testing the actual loads (or computer simulation – in the case of a prototype), proposing a modification to the system (usually hydraulic), simulating and optimising the proposed system.
Hydraulic drive and control systems
As a research team, we offer our services in the field of design of hydraulic drives and control of pressure systems. Our experience in this area allows us to approach each problem individually and solve it effectively. The process of designing hydraulic drives and controls is complex and requires a conscious determination of the parameters of the designed system taking into account technical needs and expectations as well as performing a precise analysis of movements and loads. Therefore, it requires extensive practical knowledge and access to specialized computer programs.
In working machines containing hydraulic systems, it is possible to determine the dynamics of their operation using simulation calculations, e.g. in the AMESim system. Based on the scheme of hydraulic system (Fig. 1a), a simulation model is created (Fig. 1b). It is necessary to determine the parameters of the model, which often have to be determined experimentally. On the basis of the calculations, for example, the pressure courses in the cylinder as well as the displacement, velocity and acceleration of the piston are obtained, which are shown in Fig. 3. In the next stage, it is possible to study the influence of individual parameters of the hydraulic system on its dynamics. In this way, overloads occurring during the operation of hydraulic drive systems can be limited.
Control, safety and diagnostic systems for off-road machines and vehicles
Over the past years, the Department has been repeatedly and successfully engaged in work aimed at developing various types of control, monitoring and safety systems for off-road vehicles and machines.
Among others, the following fully functional technology demonstrators were developed in the Department:
- A system to automate the process of scooping granular materials by a bucket loader,
- A system to assist the loader’s bucket scooping process by vibrating the cutting edge of its bucket,
- An on-board system for monitoring the rollover stability of a wheeled articulated bucket loader,
- An on-board system for monitoring the rollover stability of a tracked vehicle equipped with a manipulator,
- A system to support the tool positioning process of a single-arm excavator,
- An automatic system to minimize the snaking phenomenon of a wheeled articulated vehicle,
- A system to minimize the beveling of the crane on the track.
Many of the developed solutions have been submitted for legal protection and obtained patents. Despite the fact that the Department belongs to the Faculty of Mechanical Engineering of Wroclaw University of Technology, it also employs scientists who graduated from faculties significantly related to automation and robotics. Our employees have extensive knowledge of off-road machines and vehicles and have extensive experience in designing various types of control and monitoring systems.
Control systems based on the industrial grade Danfoss PLUS+1® controllers
The research and commercial services offered by the Department of Off-Road Machine and Vehicle Engineering focus on developing control systems for hydrostatic drives and working gear implemented in earthmoving, agricultural and other off-road mobile machinery. We have a great experience in designing advanced control algorithms, user-friendly Human-Machine-Interfaces and developing reliable software compatible with a wide variety of hardware platforms, including the industrial grade Danfoss PLUS+1® controllers which have been successfully implemented in a number of systems developed by us. Apart from the above-mentioned experience, we have a laboratory fitted with a bunch of ready-to-use professional hardware, i.e. a number of sensors, the SC024, MC088, DP250 and DP600 Danfoss PLUS+1® controllers, universal development boards and software development environment. Consequently, we can quickly develop working prototypes of various control systems.
Each of the above-mentioned controllers is compliant with the standard industrial signals, e.g. the 4 … 20 mA current loop and the 0 … 10 VDC voltage, can communicate via CAN bus and features high-current analog outputs which might be used to directly control the hydraulic proportional directional valves. Furthermore, they are rated with IP67 protection class. The above-mentioned characteristics make them perfectly suited to be used in the remote networks where a number of nodes are joined together to control or monitor hydraulic drives of mobile work machines.
The videos below show examples of how the controllers have been used in applications created by the Department’s employees.
Unconventional load and displacement transducers
The Department’s employees have extensive, many years of experience in designing and manufacturing force and torque transducers (mainly based on resistance strain gauges) for applications where it is not possible to use typical sensors available on the market. This often requires minimizing the interference with the existing device as well as the implementation of a sensor that allows the measurement of multiple load components, taking into account their interactions.
The department offers its services both in the field of design and execution, as well as assembly and commissioning at the recipient’s place of force and moment transducers (up to 6 components) with the necessary accessories.
