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Process Control Issues • The Process: Material Diagram • The Machine Control Diagram. In all cases, the processes involve plastic deformation of the workpiece, and the resulting strong forces required to create plastic stresses. The major difference is that the latter involves a complex three-dimensional flow of the material, while the former tends to be dominated by plane strain conditions,...
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Mating of part features is the main function of the assembly process. Type II assemblies are those where some or all of the assembly features and/or their relative locations are defined during assembly. Monitoring of an assembly process can be accomplished by either directly monitoring the quality characteristics of the assembled products (i.e., key product characteristics or KPCs), or monitoring...
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This chapter provides an overview of modeling, measurement, and control strategies in polymer pro- cessing, and discusses some of the difficulties posed by their complex and distributed nature.. Most plastic parts are fabricated by thermoforming, extrusion, or injection molding. The resulting part typically exhibits thickness distributions from 10 to 90% of the initial sheet thickness, with mold cycle times varying...
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Typically, the term random implies that the causes of the errors are not understood and cannot be eradicated. Figure 10.1 presents some of the factors affecting workpiece accuracy. Accuracy : A quantitative measure of the degree of conformance to recognized national or international standards of measurement.. Repeatability : A measure of the ability of a machine to sequentially position a...
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11.1 Introduction 11.2 Active Struts. 11.3 Active Tendon Control. 11.4 Active Damping Generic Interface 11.5 Microvibrations. 11.6 Conclusions. 11.1 Introduction. 11.2 Active Struts. 11.2.1 Open-Loop Dynamics of an Active Truss. (11.1) where d 33 is the piezoelectric coefficient, n is the number of piezoelectric ceramic elements in the actuator. This equation neglects the hysteresis of the piezoelectric expansion.. As for...
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12.1 Introduction. 12.2 Semi-Active Suspensions Design. 12.3 Adjustable Suspension Elements. 12.4 Automotive Semi-Active Suspensions. 12.5 Application of Control Techniques to Semi-Active Suspensions. 12.6 Practical Considerations and Related Topics. 12.1.1 Vibration Isolation vs. Unlike the isolator, a vibration absorber consists of a secondary system (usually mass–spring–damper trio) added to the primary device to protect it from vibrating (see Figure 12.1c). 12.1.2...
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Semi-Active Suspension Systems II. 13.1 Concepts of Semi-Active Suspension Systems. 13.2 Control Design Methodology. 13.3 Properties of Semi-Active Suspensions:. 13.4 Examples of Practical Applications. 13.1.1 Karnopp’s Original Concept. FIGURE 13.1 Variable damper and the working principle.. FIGURE 13.2 Variable force transfer and the working principle.. FIGURE 13.3 Variable spring stiffness and the working principle.. Using these semi-active devices the properties...
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14.1 Introduction. 14.2 Delayed Resonator Dynamic Absorbers. Stability of the active system.. 14.2.1 The Delayed Resonator Dynamic Absorber with Acceleration Feedback. (14.5) By this selection of the feedback gain and delay, i.e., g = g c and τ = τ c , the DR can be tuned to the desired frequency ω c in real time. (14.8) where:. (14.9) With...
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15.1 Introduction. 15.3 Active-Passive Hybrid Piezoelectric Network Treatments for General Modal Damping and Control. 15.4 Active-Passive Hybrid Piezoelectric Network Treatments for Narrowband Vibration Suppression. 15.5 Nonlinear Issues Related to Active-Passive Hybrid Piezoelectric Networks. 15.6 Summary and Conclusions. Some of the advantages of piezo- electric actuators include high bandwidth, high precision, compactness, and easy integration with existing host structures to form...
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16.1 Introduction 16.2 Cantilevered Beam. 16.3 Axially Moving Web. 16.4 Flexible Link Robot Arm. 16.5 Summary. 16.1 Introduction. In contrast to distributed sensing/actuation control techniques, boundary controllers are applied at the boundaries of the flexible system, and as a result, require fewer sensors/actuators.. (16.1) along with the boundary conditions. (16.2) where denotes the independent position variable, denotes the independent time...
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17.1 Introduction. 17.5 Concluding Remarks. 17.1.1.1 Tension Stabilizes. 17.1.3 The Analyzed Structures. FIGURE 17.3 Tensegrity structures.. 17.1.4.2.3 Summary. 17.1.5 Mass vs. (17.15). (17.19). (17.21). (17.24). (17.31). 17.2.3.1 Bucklings Load. (17.36). (17.37) where. p 2 = F/EI, (17.38). and B = e (17.40). From (17.41),. (17.42). (17.43). (17.44). (17.45) A e pL. (17.46). (17.48). (17.49). (17.50). (17.51). η ≥ F (17.52)....
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18.1 Introduction. 18.2 Tensegrity Definitions. Coordinate Transformations 18.5 Tendon Forces. 18.6 Conclusion. Appendix 18.A Proof of Theorem 18.1. (i, 1) Appendix 18.D Example Case (n,m. (3,1) Appendix 18.E Nodal Forces. FIGURE 18.2 Buckytubes.. 18.2.1 A Typical Element. FIGURE 18.6 A typical ij element.. FIGURE 18.7 Class 1 shell: (n,m. (18.10). t 7n(j–1) (18.11). (18.12). (18.13) and for j = m...
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19.1 Introduction. 19.2 Description of Orientation. 19.3 Direct Kinematics. 19.4 Inverse Kinematics. 19.5 Differential Kinematics. 19.6 Differential Kinematics Inversion. 19.7 Inverse Kinematics Algorithms. 19.8 Further Reading. 19.2.1 Rotation Matrix. (19.7) By using the following relations:. Equation (19.8) can be cast in the more compact form. (19.9) where I is the (3 × 3) identity matrix and S. (19.10). (19.11). (19.12)....
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20.1 Fundamentals of Robot Dynamic Modeling. 20.2 Recursive Formulation of Robot Dynamics. 20.3 Complete Model of Robot Dynamics. 20.4 Some Applications of Computer-Aided Dynamics. 20.1.1 Basic Ideas. FIGURE 20.1 Robot as a simple and open chain.. Figure 20.2 shows one link of the robot chain, the j -th one. (20.2) The tilde. FIGURE 20.2 Geometry of a link.. that (20.7)...
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21.1 Robot Driving Systems. 21.2 Computer-Aided Design. Section 21.2 gives the principles of advanced design. 1,2 Such a model of the complete dynamics is derived in Sections 21.3.1 and 21.3.2.. 21.1.1 Present State and Prospects. 21.1.2 DC Motors: Principles and Mathematics. Figure 21.1 shows two rotor shapes, cylindrical and disc. FIGURE 21.1 Different rotor shapes enable different overall shape of...
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22.3 Control of a Single Joint of the Robot. To accomplish various tasks, the hand of the robot (or the payload, or the tool) has to be placed in the desired locations at the workplace and take the desired orientation (and, sometimes, to produce certain desired forces upon the other objects in the workspace). In this case, the operator of...
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23.1 Introduction 23.2 Contact Tasks. 23.3 Classification of Robotized Concepts for Constrained Motion Control. 23.6 Active Compliant Motion Control Methods. 23.7 Contact Stability and Transition. 23.9 Conclusion. 23.1 Introduction. 23.2 Contact Tasks. FIGURE 23.1 Basic classification of robot compliance.. FIGURE 23.2 Passive compliance classification.. 23.4 Model of Robot Performing Contact Tasks. (23.2) where is the output angle of the motor...
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is not very crucial to the effectiveness of the network. One of the earliest sensory connectionist methods capable of serving as an alternative to the well-known backpropagation algorithm is the CMAC (cerebellar model arithmetic computer) 20 (Figure 24.2). CMAC is an associative neural network using the feature that only a small part of the network influences any instantaneous output. In...
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25.1 Introduction 25.2 Hand Controllers. 25.1 Introduction. Thus, teleoperators or the activities of teleoperation extend the manipulative capabilities of the human arm and hand to remote, physically hostile, or dangerous environments. In these very successful systems, the slave arm at the remote site is mechanically or electrically coupled to the geometrically identical or similar master arm handled by the operator...
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26.1 Introduction 26.2 Fundamental Issues. 26.3 Dynamics of Mobile Robots 26.4 Control of Mobile Robots. 26.1 Introduction. In Section 26.2 of this chapter, fundamental issues are explained regarding nonholonomic systems and how they differ from holonomic ones. Section 26.3 covers dynamics of mobile robots. 26.2 Fundamental Issues. 26.2.1 Definition of a Mobile Robot. where φ defines the orientation of the...