Feed rate control in robotic bone drilling process

2020 ◽  
pp. 095441192097589
Author(s):  
Tony Boiadjiev ◽  
George Boiadjiev ◽  
Kamen Delchev ◽  
Ivan Chavdarov ◽  
Roumen Kastelov
Keyword(s):  
Rate Control ◽  
Feed Rate ◽  
Control Algorithm ◽  
Force Sensor ◽  
Sensor Data ◽  
Drilling Process ◽  
Drill Bit ◽  
Bone Drilling ◽  
Hole Quality ◽  
Rate Control Algorithm

The bone drilling process is characterised by various parameters, the most important of which are the feed rate (mm/s) and the drill speed (rpm). They highly reflect the final effects and results of the drilling process, such as mechanical and thermal damages of bone tissue and hole quality. During manual drilling, these parameters are controlled by the surgeon based on his practical skills. But automatic drilling can assure an optimal result of the manipulation where such parameters are under control. During bicortical automatic bone drilling such a process consists of several stages: searching the contact with the first cortex, cortex drilling and automatic stop; searching the contact with the second cortex, cortex drilling and automatic stop; drill bit extraction. This work presents a way to control the feed rate during different stages of the bone drilling process (an original feed rate control algorithm) using the orthopaedic drilling robot (ODRO). The feed rate control is based on a proposed algorithm created and realised by specific software. During bicortical bone drilling process the feed rate takes various values in any stage in the range 0.5–6 mm/s. These values depend on drill bit position and real time force sensor data. The novelty of this work is the synthesis of an original feed rate control algorithm to solve the main problems of bone drilling in orthopaedic surgery – minimisation the drilling time (the heat generation); eliminating of the drill bit slip at the first (near) cortex and the drill bit bending at the second (far) cortex; minimising the risk of micro cracks which causes Traumatic Osteonecrosis; improving hole quality of the drilled holes; eliminating of the drill bit slip and the drill bit bending at the second cortex; minimising the value of the second cortex drill bit penetration by bicortical bone drilling.

HBsAg Production in Methanol Controlled P. pastoris GS115 MutS Bioreactor Process

2021 ◽  
Vol 903 ◽  
pp. 40-45
Author(s):  
Oskars Grigs ◽  
Emīls Bolmanis ◽  
Andris Kazaks
Keyword(s):  
Pichia Pastoris ◽  
Rate Control ◽  
Feed Rate ◽  
Control Algorithm ◽  
Methanol Concentration ◽  
Size Exclusion ◽  
Stirred Tank Bioreactor ◽  
Purification Method ◽  
Methanol Sensor ◽  
Rate Control Algorithm

When producing recombinant proteins with Pichia pastoris, cultivation parameters, such as induction temperature, dissolved oxygen level and residual methanol concentration play a crucial role in product biosynthesis and subsequent purification, therefore to maximize protein yields, the optimization of these parameters is imperative. Two different Pichia pastoris cultivation strategies for HBsAg VLP production in a 5 L stirred-tank bioreactor and the influence of different cultivation parameters on product yield were investigated. Residual methanol concentrations were controlled at low (>0.01 g/L), medium (1.5-2.0 g/L) and high (5.0-6.0 g/L) levels using a PI-based feed rate control algorithm based on the online methanol sensor signal. Product was purified using a novel and rapid purification method including steps of ammonium sulfate precipitation, size-exclusion chromatography and hydrophobic interaction chromatography. Employing an in-situ methanol sensor probe, the PI-based methanol feed rate control algorithm provided residual methanol concentration control with an average deviation of ±0.4 g/L from set-point value. Employing a cultivation protocol with an increased methanol concentration controlled at 6.0 g/L and a reduced DO level below 10 %, resulting in a final dry cell biomass concentration of 140 g/L and purified HBsAg VLPs yield of 186 mg/L. Developed purification method proved advantageous to other described methods, as it did not include time consuming extraction and centrifugation steps.

Investigation, sensitivity analysis, and multi-objective optimization of effective parameters on temperature and force in robotic drilling cortical bone

2017 ◽  
Vol 231 (11) ◽  
pp. 1012-1024 ◽  
Author(s):  
Vahid Tahmasbi ◽  
Majid Ghoreishi ◽  
Mojtaba Zolfaghari
Keyword(s):  
Sensitivity Analysis ◽  
Feed Rate ◽  
Process Temperature ◽  
Drilling Process ◽  
Drilling Speed ◽  
Multi Objective Optimization ◽  
Bone Drilling ◽  
Multi Objective ◽  
Tool Diameter ◽  
First Time

The bone drilling process is very prominent in orthopedic surgeries and in the repair of bone fractures. It is also very common in dentistry and bone sampling operations. Due to the complexity of bone and the sensitivity of the process, bone drilling is one of the most important and sensitive processes in biomedical engineering. Orthopedic surgeries can be improved using robotic systems and mechatronic tools. The most crucial problem during drilling is an unwanted increase in process temperature (higher than 47 °C), which causes thermal osteonecrosis or cell death and local burning of the bone tissue. Moreover, imposing higher forces to the bone may lead to breaking or cracking and consequently cause serious damage. In this study, a mathematical second-order linear regression model as a function of tool drilling speed, feed rate, tool diameter, and their effective interactions is introduced to predict temperature and force during the bone drilling process. This model can determine the maximum speed of surgery that remains within an acceptable temperature range. Moreover, for the first time, using designed experiments, the bone drilling process was modeled, and the drilling speed, feed rate, and tool diameter were optimized. Then, using response surface methodology and applying a multi-objective optimization, drilling force was minimized to sustain an acceptable temperature range without damaging the bone or the surrounding tissue. In addition, for the first time, Sobol statistical sensitivity analysis is used to ascertain the effect of process input parameters on process temperature and force. The results show that among all effective input parameters, tool rotational speed, feed rate, and tool diameter have the highest influence on process temperature and force, respectively. The behavior of each output parameters with variation in each input parameter is further investigated. Finally, a multi-objective optimization has been performed considering all the aforementioned parameters. This optimization yielded a set of data that can considerably improve orthopedic osteosynthesis outcomes.

scholarly journals Optimization of Drilling Process Parameters Via Taguchi, TOPSIS and RSA Techniques

2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Research Work ◽  
Cutting Speed ◽  
High Strength ◽  
Drilling Process ◽  
Drill Bit ◽  
Influence Of Process Parameters ◽  
Light Trucks ◽  
Cfrp Composite

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.

scholarly journals Comparative study on the redundancy of mobile single- and dual-arm robots

2016 ◽  
Vol 13 (6) ◽  
pp. 172988141666678
Author(s):  
Hongxing Wang ◽  
Ruifeng Li ◽  
Yunfeng Gao ◽  
Chuqing Cao ◽  
Lianzheng Ge
Keyword(s):  
Rate Control ◽  
Control Algorithm ◽  
Redundant Robot ◽  
Motion Models ◽  
Redundant Robots ◽  
Operational Space ◽  
Rate Control Algorithm ◽  
Simulation Results ◽  
Dual Arm Robot ◽  
Dual Arm

A whole resolved motion rate control algorithm designed for mobile dual-arm redundant robots is presented in this article. Based on this algorithm, the end-effector movements of the dual arms of the mobile dual-arm redundant robot can be decomposed into the movements of the two driving wheels of the differential driving platform and the movements of the dual-arm each joint of this robot harmoniously. The influence of the redundancies of the single- and dual-arm robots on the operation based on the fixed- and differential-driving platforms, which are then based on the whole resolved motion rate control algorithm, is studied after building their motion models. Some comparisons are made to show the advantages of this algorithm on the entire modeling of the complicated robotic system and the influences of the redundancy. First, the comparison of the simulation results between the fixed single-arm robot and the mobile single-arm robot is presented. Second, a comparison of the simulation results between the mobile single-arm robot and the mobile dual-arm robots is shown. Compared with the mobile single-arm robot and the fixed dual-arm robot based on this algorithm, the mobile dual-arm robot has more redundancy and can simultaneously track and operate different objects. Moreover, the mobile dual-arm redundant robot has better smoothness, more flexibility, larger operational space, and more harmonious cooperation between the two arms and the differential driving platform during the entire mobile operational process.

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