ISSN / EISSN : 0957-4158 / 1873-4006
Published by: Elsevier BV (10.1016)
Total articles ≅ 2,740
Latest articles in this journal
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102668
The RMP-100 is an underactuated robot known in the literature as two wheeled inverted pendulum (TWIP). This mechanism has two independent wheels that allow to perform two tasks simultaneously: keep the inverted pendulum in its upright position (balancing) and move the robot to a specific location on the workspace terrain. This paper proposes (as an extension of the work of Gutiérrez Frías, 2013) a nonlinear Lyapunov-based controller with the purpose to stabilize the pose (position and orientation) of the robot while balancing the pendulum. Moreover, asymptotic stability is proven using LaSalle’s invariance principle. Furthermore, the development of a new software for implementing real-time controllers on the RMP-100 is briefly explained; and finally, in order to validate the performance of the proposed controller, experimental results are included.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102647
Active thermal control is crucial in achieving the required accuracy and throughput in many industrial applications, e.g., in the medical, high-power lighting, and semiconductor industry. Thermoelectric Modules (TEMs) can be used to both heat and cool, alleviating some of the challenges associated with traditional electric heater based control. However, the dynamic behavior of these modules is non-affine in their inputs and state, complicating their implementation. To facilitate advanced control approaches a high fidelity model is required. In this paper an approach is presented that increases the modeling accuracy by incorporating temperature-dependent parameters. Using an experimental identification procedure, the parameters are estimated under different operating conditions. The resulting model is used in a feedback linearization approach to linearize the system, facilitating the use of advanced linear control techniques. Moreover, it presents an observer based approach to reconstruct state information in cases where sensor placement is limited. The resulting framework forms a complete approach to temperature-dependent modeling and control of thermoelectric elements.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102660
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102661
Shaking table is a device to simulate the vibration environment, which is used to test the reliability and seismic resistance of many products. However, the control performance of the shaking table is restricted by the serious output coupling caused by eccentric load. In order to solve the coupling problem, a new control strategy, modal space three-state feedback and feedforward control, is proposed. For a 2-DOF electro-hydraulic servo shaking table, its kinematics model and dynamics model with eccentric load are built. And then, the dynamic coupling is analyzed, which makes it impossible for each channel to be controlled independently. To avoid the effect by coupling, a modal space control framework is established based on the vibration theory and the decoupling characteristics of the modal space are researched. In modal space, although a controller of each channel can be designed dependently, the ultimate requirements are decoupling for channels in the degree of freedom space, so it is necessary to discuss the mapping relation between traditional physical space and the presented modal space. The effect of modal channel consistency on the decoupling for physical space is revealed. Furthermore, the correlation of the frequency responses between the two spaces is also analyzed. To meet the obtained conclusions of modal space, a modal space three-state feedback and feedforward controller is designed for improving the dynamic performance and the consistency of modal channels. The experimental results show the correctness of the theoretical analysis, and validate that modal space three-state feedback and feedforward control method is effective, which can significantly reduce the output coupling for the 2-DOF electro-hydraulic servo shaking table with eccentric load.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102657
Robotic multi-pass welding for thick and shape-varying weld geometry is a challenging problem. To achieve good weld quality, desired welding profile for the whole welding bevel is necessary, which requires the welding inputs to be changed appropriately in real-time. In this paper, a welding profile control with data-driven fast input allocation (PC-FIA) algorithm is proposed for robotic multi-pass welding on a shape-varying weld geometry, namely, TYK pipe-to-pipe joint. Firstly, the control algorithm is used for the welding profile control in order to suppress the error propagation during the multi-pass welding. Secondly, the welding input parameters including torch traveling speed and weaving parameters are allocated using a optimization based on the identified weld input constraint from a data-driven approach. Experimental results show that the weld profile using the proposed method achieves 60% decrease of root-mean-square error with respect to the planned reference, as compared to the case of without using the proposed PC-FIA method. In addition, the allocated weaving parameters ensure that the welding inputs are always maintained within the polyhedral constraint and the whole welding quality is acceptable by industry standard.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102659
Permanent magnet synchronous motors are widely used in elevator applications. This is due to their high efficiency and reliability, whereby motors are directly connected to the elevator ropes without the need of having a gearbox. This efficient system comes with some new challenges regarding the control of the motor. Since no gearbox is added to the system, the motor speed oscillations are directly transferred to the elevator cabin. This urges the need of having a smooth control algorithm to suppress the measurement noises generated by the absolute encoder especially at low speed. On the other hand, whenever the mechanical brakes are released, the speed controller needs to react quickly to prevent the cabin from rolling back. In order to overcome these challenges, this paper presents an improved speed control algorithm that reacts quickly in transient state to reduce the rollback of the cabin and slowly at steady state to ensure smooth ride. The proposed controller is based on the combination of a Model Predictive Controller (MPC) along with a torque observer. It also benefits from being computationally less demanding unlike other MPC techniques. The proposed controller is experimentally tested on an elevator and then compared to classic controllers. Finally, conclusions are drawn.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102658
Amongst all these resistive forces in a modern passenger car, depending on the driving conditions and tire specifications, about 20–30% of total fuel consumption is related to rolling resistance. The rolling resistance of the vehicle is still rather unknown and research should be conducted to be able to estimate it reliably and accurately. This accuracy is particularly necessary at the scale of a single vehicle to reduce the fuel consumption, considering that the rolling resistance coefficient is a dimensionless quantity with an order of magnitude of 1 to 2%. The purpose of this paper is to develop an unknown input adaptive gain estimation algorithm for the accurate estimation of the rolling resistance of a vehicle. This is motivated by the fact that the adaptive solution is the most suitable for the rolling resistance estimation because of variable dynamics and continuous change in a situation during the real driving situation. Their robustness to modelling error, parameter uncertainty and input noise used to detect the variation in the input. The developed approach is validated experimentally with a relative mean error of less than 10%. The experiments were done on University Gustave Eiffel test tracks.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102648
A suspended Cable-Driven Parallel Robot (CDPR) composed of eight cables and a moving platform (MP) is used in a pick-and-place application of metal plates with different shapes, sizes and masses. In order to ensure robust control despite mass variation, several combinations of control schemes and control laws have been experimented on a prototype at IRT Jules Verne, France. The main objective of this paper is to provide recommendations on the selection of a control strategy depending on the available information on the carried mass, and the presence or absence of force sensors. Three scenarios are considered representing a degradation of the information on the carried mass to observe the impact on the performance of applicable control strategies. In a first case, force sensors are assumed available to measure cable tension, allowing the real-time estimation of the carried mass. In a second case, the mass of the MP is known, but not the mass of the carried metal plate whereas the third case considers no information at all on both the MP and the carried metal plate. The tested control laws include a standard proportional–derivative controller (PD), and a recently developed nonlinear controller balancing between sliding mode and linear algorithms (SML). The performances of each control strategy are analyzed along a test trajectory for several payloads, and a decision tree is proposed.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102649
This study implemented a micro-Electrical Discharge Machining (micro-EDM) system based on Electrical Spark Discharge Method (ESDM) with real-time monitoring system to fabricate TiO2 nanocolloid. This system is relatively small size and low cost compared with industrial EDM machine. The real-time monitoring and control function of this system was achieved with VisSim software, an RT-DAC4/PCI card, and a designed servo circuit. Among the colloid prepared by micro-EDM system with two PID parameters, the colloid prepared using the PID parameters to get absorbance, average particle size, and suspensibility. The experimental results indicated that the colloid had absorbance of 0.187, ζ potential of -27.4 mV, average particle size of 223.9 nm, and percentage of colloidal particles smaller than 91.28 nm of 78.7% when the micro-EDM system Ton–Toff pulse period was set to 30–30 µs, the colloid production time was set to 20 min, and the PID controller parameter were set to Kp = 0.88, Ki = 0.045, and Kd = 0.035. TiO2 nanocolloid preparation in this study was completed in DW. The preparation process did not cause dust dissipation and was thus a green preparation method with low energy consumption.
Mechatronics, Volume 79; https://doi.org/10.1016/j.mechatronics.2021.102640
In this paper, a driving system of the soft massage robot was presented, capable of switching between curved and vertical states to complete palm kneading and palm pressing. The bending and the vertical state were achieved by filling unequal-pressure and isobaric gas into 3 actuators respectively. On that basis, first, the theoretical model between F and L, D, D1, D2, h1, Pjin at the vertical state was built by complying with the force balance equation and the moment balance equation. Second, the actuator was simplified as an equivalent spring, and then the kinematics model at the bending state was established. Lastly, the output force model at the bending state was set in accordance with the force balance equation again. To verify the accuracy of the workspace and the output force, a set of experimental equipment was built, consisting of a pneumatic module prototype, a pneumatic control system, as well as an experimental testing device. Furthermore, the stability of the pneumatic module performance was determined by performing the repeated experiments, and the consistency between the theoretical model and the experimental results was verified.