Everyone is invited to a seminar this Friday by Elhamosadat Alavi Foumani. Elham will be giving a talk on crack detection in bladed disks. The seminar abstract is below.
Date: Friday 1st February.
Location: SITE G0103
I hope to see you all there.
Bladed Disk Crack Detection Through Advanced Analysis of Blade Passage Signals
BY: Elhamosadat Alavi Foumani
Abstract: Health condition monitoring and fault diagnostics of turbo fan engines play significant roles in overall cost reduction and reliability enhancement of the aircraft system. Among various types of potential faults in a turbo fan engine, crack initiation and propagation in the bladed disks of engines caused by high-cycle fatigue under cyclic loads are typical ones that could result in the breakdown of the engines if not detected at an early stage. Although a number of approaches have been reported in literature, it still remains very challenging to develop a reliable technique to accurately estimate the health condition of bladed disks of engines. As such, this work presents a new technique for engine bladed disk crack detection through advanced analysis of blade tip clearance and time-of-arrival signals. Two stages of signal processing are involved in this technique: 1) signal pre-processing for removing the noise caused by rotor imbalance; and 2) signal post-processing for identifying the initiation and location of the crack. The effectiveness of the developed technique is validated experimentally in a spin rig test.
Jaime Murillos presented this thesis seminar this past Friday, talking about how he developed a new Pneumatic Artificial Muscle for his master’s project.
Photo of Jaime with supervisor Dr. Marc Doumit is below – click on the photo for a larger version.
Dr. Marc Doumit with MASc student Jaime Murillo
- Dr. Marc Doumit with MASc student Jaime Murillo
Everybody is cordially invited to attend Jaime Murillo’s MASc thesis seminar this Friday. The title of the talk is ” Design of a Pneumatic Artificial Muscle for Powered Lower Limb Prostheses”. The talk abstract is below.
Date: Friday 25th January
Room: SITE G0103
I hope to see you all there!
DESIGN OF A PNEUMATIC ARTIFICIAL MUSCLE FOR POWERED LOWER LIMB PROSTHESES
By Jaime Murillo
Ideal prostheses are defined as artificial limbs that would permit physically impaired individuals freedom of movement and independence rather than a life of disability and dependence. Current lower limb prostheses range from a single mechanical revolute joint to advanced microprocessor controlled mechanisms. Despite the advancement in technology and medicine, current lower limb prostheses are still lacking an actuation element that prohibit patients from regaining their original mobility and improve their quality of life.
This thesis aims to design and test a Pneumatic Artificial Muscle that would actuate lower limb prostheses which would offer patients the ability to ascend and descend stairs as well as standing up from a sitting position. A comprehensive study of knee biomechanics is first accomplished to characterize the actuation requirement, and subsequently a Pneumatic Artificial Muscle design is proposed. A novel design of muscle end fixtures is presented which would allow the muscle to operate at a gage pressure surpassing 2.76 MPa (i.e. 400 psi) and yield to a muscle force that is at least 3 times greater than any existing Pneumatic Artificial Muscle force. Finally, the proposed Pneumatic Artificial Muscle is tested and validated to verify that it meets the size, weight, kinetics as well as kinematics requirements of a human knee articulation.
Dr. Hallett recently gave a presentation on writing an engineering report or thesis: Writing Engineering Theses and Reports
Want more details? Consult his short article on the same topic, which you can read here.
This Friday, we have a special seminar to be given by Dr. Hallett on Writing Theses and Reports in Engineering. I think that we can all benefit from attending this seminar to pick up some writing tips from Dr. Hallett. Although the seminar is being presented as part of our graduate seminar series, everyone is welcome (in particular 4th year undergrads).
Writing Theses and Reports in Engineering
Abstract: This seminar will cover the basics of writing research theses and reports in engineering, including format, style, presentation of data, graphs, and references.
Date: Friday 18th January
Room: SITE G0103
Elisha Pruner and Mostafa Mohammed, both under the supervision of Dr. Dan Necsulescu presented their MASc research last Friday. Lots of questions were asked and for the first time, we almost ran out of our allotted seminar time! For those who missed it, you can still check out Elisha’s seminar slides.
Photos of the students with their supervisor are below, click on the photo for a larger version.
Elisha Pruner with supervisor Dr. Dan Necsulescu
Mostafa Mohammed with supervisor Dr. Necsulescu
To kick things off for our seminar series, we are starting with a graduate student double header this Friday. Elisha Pruner will give a talk on “Formation control of multi-robot teams using geometric and self-organizing approaches” and Mostafa Mohammed will talk about “Application of Mechatronics in Individual Drive Electric Motors for Unmanned Off-road Wheeled Vehicles”.
The seminar abstracts are below
Date: Friday 11th January
Room: SITE G0103
Hope to see you all there!
Formation control of multi-robot teams using geometric and self-organizing approaches
In certain applications, such as search and rescue, reconnaissance, and surveillance, many small inexpensive vehicles working as a team can achieve more than one sophisticated vehicle working on its own. Currently, there is a strong motivation to implement multi-vehicle teams since they can perform tasks with greater efficiency, less cost, and they present a more robust solution. However, the disadvantage of multi-vehicle systems is that they require a high level of organization and coordination in order to successfully complete a task. Formation control is a field of engineering that addresses this issue, and provides coordination schemes to successfully implement multi-vehicle systems. In this research two types of formation controllers were developed: geometric and self-organizing. Firstly, a geometric formation controller was created using a leader-follower setup and a PD controller, generating military style formations for the robot teams such as platoon and V-formation. Furthermore, a self-organizing controller was developed using a velocity-potential approach to create swarming movements for the robot team with no pre-defined shape. Both geometric and self-organizing formation controllers were first prototyped in MATLAB simulation; they were then programmed onto three differential drive mobile robot platforms for experimental testing. The results confirmed the validity of both formation control approaches.
Application of Mechatronics in Individual Drive Electric Motors for Unmanned Off-road Wheeled Vehicles
Under the supervision of Dr. Dan S. Necsulescu
Energy consumption optimization is applied to a mobile robot to benefit from the kinetic energy gained along downhill slopes, in the off-road environment, to overcome the uphill slopes. Predictive control is used, assuming that the robot knows the environment map ahead of time before reaching a ditch. The energy consumed as well as the motors’ speed profiles during the operation are investigated. The simulation results obtained are compared to those of a PID speed controller and to those of an open-loop control of the DC motors. The results obtained with predictive controller showed a noticeable reduction in the energy consumption over the PID controller and the open-loop control which failed to overcome the ditch. An experimental work was conducted using wood made ramps to represent the ditch in a laboratory environment. A mobile robot is required to attempt crossing the ditch. The experimental results showed good agreement with the simulation results for open-loop, PID and predictive controllers. Predictive controller proved the most efficient solution.