Design of an Innovative Test Rig for Industrial Bearing Monitoring with Self-Balancing Layout

The remote prognosis and diagnosis of bearings can prevent industrial system failures, but the availability of realistic experimental data, being as close as possible to those detected in industrial applications, is essential to validate the monitoring algorithms. In this paper, an innovative bearing test rig architecture is presented, based on the novel concept of “self-contained box”. The monitoring activity is applicable to a set of four middle-sized bearings simultaneously, while undergoing the independent application of radial and axial loads in order to simulate the behavior of the real industrial machinery. The impact of actions on the platform and supports is mitigated by the so-called “self-contained box” layout, leading to self-balancing of actions within the rotor system. Moreover, the high modularity of this innovative layout allows installing various sized bearings, just changing mechanical adapters. This leads to a reduction of cost as well as of system down-time required to change bearings. The test rig is equipped with suitable instrumentation to develop effective procedures and tools for in- and out-monitoring of the system. An initial characterization of the healthy system is presented.

Novel Insole Material for Weight-Bearing Monitoring Medical Device to Be Used in Fractured Bone Clinic

Partial Weight-Bearing (PWB) regime is a part of a recreation process for patients with lower limb fractures/strains/sprains. In order to avoid a frequent foot overloading and achieve better patient compliance with requirement of PWB, the application of Weight-Bearing Monitoring System (WBMS) is highly attractive. However, it is challenging to find an affordable material for protective insole cover that is also a good shock-absorber. In this regard, a new formulation for protective covering material that preserves and isolates the sensors of WBMS device is suggested in this thesis. Twenty one samples of renewably sourced Polyurethane Foam (PUF) composed of poly (trimethylene ether) glycol (PO3G) and unmodified castor oil (CO) were synthesized and evaluated according to predetermined criteria. Response surface methodology of Box – Behnken design was applied to study the effect of the following parameters (polyols ratio, isocyanate index (II), and blowing agent ratio) on the properties (hardness, density) of PUFs. Results showed that CO/PO3G/TDI PUFs with hardness Shore A 17-22 and density of 0.19-0.25 g/cm3 demonstrate the required characteristics and can potentially be used as a durable and functional insole material. Phase separation studies have found the presence of well-segregated structure in PUFs having polyols ratio CO:PO3G 1:3 and low II, which further explains their extraordinary elastic properties (400% elongation). Analysis of cushioning performance of PUF signified that 5 samples have Cushioning Energy (CE) higher than 70 N·mm and Cushioning Factor (CF) in the range of 4-8, hence are recommended for application in WBMS due to superior weight-bearing and pressure-distributing properties. Moreover, the developed formulation undergoes anaerobic soil bacterial degradation and can be categorized as “green” bio-based material.

Novel Insole Material for Weight-Bearing Monitoring Medical Device to Be Used in Fractured Bone Clinic

Partial Weight-Bearing (PWB) regime is a part of a recreation process for patients with lower limb fractures/strains/sprains. In order to avoid a frequent foot overloading and achieve better patient compliance with requirement of PWB, the application of Weight-Bearing Monitoring System (WBMS) is highly attractive. However, it is challenging to find an affordable material for protective insole cover that is also a good shock-absorber. In this regard, a new formulation for protective covering material that preserves and isolates the sensors of WBMS device is suggested in this thesis. Twenty one samples of renewably sourced Polyurethane Foam (PUF) composed of poly (trimethylene ether) glycol (PO3G) and unmodified castor oil (CO) were synthesized and evaluated according to predetermined criteria. Response surface methodology of Box – Behnken design was applied to study the effect of the following parameters (polyols ratio, isocyanate index (II), and blowing agent ratio) on the properties (hardness, density) of PUFs. Results showed that CO/PO3G/TDI PUFs with hardness Shore A 17-22 and density of 0.19-0.25 g/cm3 demonstrate the required characteristics and can potentially be used as a durable and functional insole material. Phase separation studies have found the presence of well-segregated structure in PUFs having polyols ratio CO:PO3G 1:3 and low II, which further explains their extraordinary elastic properties (400% elongation). Analysis of cushioning performance of PUF signified that 5 samples have Cushioning Energy (CE) higher than 70 N·mm and Cushioning Factor (CF) in the range of 4-8, hence are recommended for application in WBMS due to superior weight-bearing and pressure-distributing properties. Moreover, the developed formulation undergoes anaerobic soil bacterial degradation and can be categorized as “green” bio-based material.

Degradation state prediction of rolling bearings using ARX-Laguerre model and genetic algorithms

This study is motivated by the need for a new advanced vibration-based bearing monitoring approach. The ARX-Laguerre model (autoregressive with exogenous) and genetic algorithms (GAs) use collected vibration data to estimate a bearing’s remaining useful life (RUL). The concept is based on the actual running conditions of the bearing combined with a new linear ARX-Laguerre representation. The proposed model exploits the vibration and force measurements to reconstruct the Laguerre filter outputs; the dimensionality reduction of the model is subject to an optimal choice of Laguerre poles which is performed using GAs. The paper explains the test rig, data collection, approach, and results. So far and compared to classic methods, the proposed model is effective in tracking the evolution of the bearing’s health state and accurately estimates the bearing’s RUL. As long as the collected data are relevant to the real health state of the bearing, it is possible to estimate the bearing’s lifetime under different operating conditions.