8 research outputs found
Distributed chance-constrained model predictive control for condition-based maintenance planning for railway infrastructures
No full textWe develop a Model Predictive Control (MPC) approach for condition-based maintenance planning under uncertainty for railway infrastructure systems composed of multiple components. Piecewise-affine models with uncertain parameters are used to capture both the nonlinearity and uncertainties in the deterioration process. To keep a balance between robustness and optimality, we formulate the MPC optimization problem as a chance-constrained problem, which ensures that the constraints, e.g., bounds on the degradation level, are satisfied with a given probabilistic guarantee. Two distributed algorithms, one based on Dantzig-Wolfe decomposition and the other derived from a constraint-tightening technique, are proposed to improve the scalability of the MPC approach. Computational experiments show that the distributed method based on Dantzig-Wolfe decomposition performs the best in terms of computational time and convergence to global optimality. By comparing the chance-constrained MPC approaches with deterministic approach, and traditional time-based maintenance approach, we show that despite their high computational requirements, chance-constrained MPC approaches are cost-efficient and robust in the presence of uncertainties.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Bart De SchutterRailway EngineeringDelft Center for Systems and Contro
Characterisation of the Dynamics of an Automotive Suspension System for On-line Condition Monitoring
No full textAs the most critical system that determines the driving performance, passenger comfort and road safety of a vehicle, the suspension system has not been found to have adequate monitoring systems available to provide early warnings of possible faults online. To fill this gap, this study has focused on the investigation of the dynamic behaviour of the suspensions upon which a new on-line condition suspension monitoring approach was proposed and verified under different conditions. Specifically, the approach quantifies the modal shapes which are obtained based on an improved modal identification applying to acceleration responses at the four corners of the vehicle. To achieve this, the research was carried out by the means of dynamic modelling, numerical simulations, optimal measurement optimisations and subspace identification improvements based on a representative vehicle system, cost-effective measurement techniques and road standards.
Firstly, a mathematical model with a seven degree-of-freedom (7-DOF) was developed in account of variable stiffness and damping coefficients, being applicable for computer simulation of the dynamic interaction between a vehicle and a road profile. To validate the proposed model during real operation, this study investigates a set of on-road experiments, to measure the acceleration of the vehicle body. Comparisons between the experimental and simulation paths demonstrated that, simulation results and measured on road results were found to be almost have similar trend.
In the simulations the modal parameters (obtained theoretically) of a vehicle are: natural frequency, damping ratio and modal shapes and their characteristics are characterised under the influence of different suspension faults and operating conditions (loads and speed). It has found that the modal shapes are more independent of operating conditions and thereby reliable as indicators of faulty suspensions, compared with modal frequency and damping which are influenced more by operating conditions. Furthermore, the modal shape difference between left and right side responses are developed as the fault severity indicator.
To obtain the modal shapes online reliably, an improved stochastic subspace identification (SSI) is developed based on an average correlation SSI. Particularly the implementation of optimal reference channels is achieved by comparing the average correlation signals which can be more efficient due to much smaller data sizes, compared with that raw data based spectrum analysis method used in original development.
On road verification based on a commercial vehicle operating in normal road conditions shows that common suspension faults including inadequate damping faults and under-inflation of the tyre, induced one of the four shock absorbers, can be detected and diagnosed with acceptable accuracy. Therefore, it can be deduced that the SSI modal shape based detection techniques are effective and therefore promising to be used to diagnose and monitor the suspension system
online
Vehicle suspension performance analysis based on full vehicle model for condition monitoring development
No full textThe objective of this research is to develop a mathematical model using a seven degree-of-freedom full car. The simulation analyses were conducted to predict the response of the vehicle when driven across speed bumps of different shapes and at range of speeds. Three bump sizes were considered in this study including bump 1 (500 mm × 50 mm), bump 2 (500 mm × 70 mm), and bump 3 (500 mm × 100 mm). These were run through the model at speeds of 8, 16, 24 and 32 km/hr. The model was validated using experimental data, which was collected by driving the vehicle across the bump 1 at a speed of 8 km/h. The performance of the suspension in terms of ride comfort, road handling and stability of the vehicle were analysed and presented. The vibration analysis for different speed levels of 8, 16, 24 and 32 km/hr indicated that, the effect of vehicle speeds on the vibration of the vehicle body increases at lower speeds up to a maximum value after which it began to decrease from the optimum point with increasing vehicle speeds. The model has been used for fault detection of under-inflation of vehicle tyre by 35%, and also to predict possible future suspension faults.</p
Pembuatan Mobil Robot Pemantau Dengankamera Pan-Tilt Berbasis Microcontroller
Get PDFIn the era of technological developments that are increasingly advanced, one of which is robot technology which is a tool that can be used as a substitute for human tasks which has several advantages. One of these advantages is that it can be used in dangerous places or places that are at high risk for humans if they run it. In this case the author is interested in making a prototype in the form of a robot car with wireless control using completeness in the form of a mobile robot for the military and industrial fields with remote control (wireless) equipped with a pantilt camera. At this time the ESP32-Cam is given a current voltage of 5 Volts and the Motor Driver L298N 12 Volts. After the ESP32-Cam is active, the robot is in a standby state.While in this condition, the smart phone or computer that will be used must first be connected to the network that has been programmed on the ESP32Cam. In the connected condition, the user then enters the appropriate IP
address into the web server application. If it has been entered, the user gets full control access rights to the monitoring robot. Users only need to press the buttons available on the available applications. The WiFi network on
the ESP32-CAM module can be connected to the robot control system with a maximum range of 45 M. If it exceeds the maximum distance, the robot will lose control and not be connected to the control system
Vehicle Suspension Performance Analysis Based on Full Vehicle Model for Condition Monitoring Development
No full textThe objective of this research is to develop a mathematical model using a seven degree-of-freedom full car. The simulation analyses were conducted to predict the response of the vehicle when driven across speed bumps of different shapes and at range of speeds. Three bump sizes were considered in this study including bump 1 (500 mm x 50 mm), bump 2 (500 mm x 70 mm), and bump 3 (500 mm x 100 mm). These were run through the model at speeds of 8 km/hr, 16 km/hr, 24 km/hr and 32 km/hr. The model was validated using experimental data, which was collected by driving the vehicle across the bump 1 at a speed of 8km/h.
The performance of the suspension in terms of ride comfort, road handling and stability of the vehicle were analysed and presented. The vibration analysis for different speed levels of 8 km/hr, 16 km/hr, 24 km/hr and 32 km/hr indicated that, the effect of vehicle speeds on the vibration of the vehicle body increases at lower speeds up to a maximum value after which it began to decrease from the optimum point with increasing vehicle speeds. The model has been used for fault detection of under-inflation of vehicle Tyre by 35%, and also to predict possible future suspension faults
A study of the Suspension System for the Diagnosis of Dynamic Characteristics
No full textSome of the common faults associated with
suspension components are damaged or leaking shock
absorbers, spring weakness, wearing down of the pivot and
bushing and damage to the main support member assembly.
To investigate these problems, a seven degree-of-freedom (7-
DOF) model has been developed, for a full vehicle, using
MATLAB. In the simulation, the suspension faults have
been considered via the damage caused to the shock
absorbers (dampers) and the faults were seeded by reducing
the damper coefficient by 25%, 50% and 80%. This has
formed the basis for the characterisation of the ride
comfort, road handling and stability of the car.
The parameters able to offer a comfortable ride for the
passengers were found to be in conflict with the parameters
ensuring the stability of the vehicle and the corresponding
wheel travel. For a high level of ride comfort, the suspension
requires a shock absorber with a low damping coefficient.
However, for optimum stability and a minimum level of
wheel motion, the suspension requires a shock absorber
with a high damping coefficient
Proceedings of First Conference for Engineering Sciences and Technology: Vol. 2
Get PDFThis volume contains contributed articles of Track 4, Track 5 & Track 6, presented in the conference CEST-2018, organized by Faculty of Engineering Garaboulli, and Faculty of Engineering, Al-khoms, Elmergib University (Libya) on 25-27 September 2018.
Track 4: Industrial, Structural Technologies and Science Material
Track 5: Engineering Systems and Sustainable Development
Track 6: Engineering Management
Other articles of Track 1, 2 & 3 have been published in volume 1 of the proceedings at this lin
