Lecture 03: Design Methodology for Mechatronics system (VDI 2206) PDF

MCT 317: Design of Mechatronics Systems (1) Lecture 03: Design Methodology for Mechatronics system (VDI 2206) Mohammed Ibrahim Dr. Eng. Mohamed Nabil Assistant Professor- Mechatronics Department 7/1...

MCT 317: Design of Mechatronics Systems (1) Lecture 03: Design Methodology for Mechatronics system (VDI 2206) Mohammed Ibrahim Dr. Eng. Mohamed Nabil Assistant Professor- Mechatronics Department 7/16/2018 [email protected] 1 From the mechanical brake to the mechatronic brake in twelve decades  Objective  The objective of this guideline is to:  provide methodological support for the cross-domain development of mechatronic systems.  The main aspects here are intended to be the procedures, methods and tools for the early phase of development, concentrating on system design. The result of system design is the assured concept of a mechatronic system.  This is understood as meaning the solution established in principle and checked by verification and validation. Introduction to the Development of Mechatronic Systems Structure of Mechatronic Systems Example of structuring of mechatronic systems Development Methodology of Mechatronics Design Procedures  Main procedures:  Requirements.  System design.  Domain specific design.  Modeling and model analysis.  System integration.  Assurance of properties.  Problem-solving cycle as a micro- cycle  Problem-solving cycle as a micro-cycle: The structuring of the procedure in the development process takes place in this case on the basis of a general problem-solving cycle, such as that known for example from systems engineering. By arranging procedural cycles in series and one within the other, process planning can be flexibly adapted to the peculiarities of any development task.  The micro-cycle of the handling organization presented here originates from systems engineering and has also been adopted in modified forms in other disciplines, such as for example business management or software engineering. Its validity in principle for the planning and implementation of effective problem-solving behavior has in this way been confirmed over and again, including from a psychological aspect. It comprises the following steps: Problem-solving cycle as a micro- cycle  Problem-solving cycle as a micro- cycle  Situation analysis or adoption of a goal: at the beginning of an elementary handling cycle there is either the situation analysis or the adoption of a goal.  The acting group or individual can adopt an externally prescribed goal, which is followed by a situation analysis (procedure governed by the desired state), or, following the analysis of an initially unclear situation, itself formulate the goal (procedure governed by the actual situation).  Analysis and synthesis: The search for solutions to the given problem takes place against the background of situation analysis and objective.  This process takes the form in practice of a permanent alternation between synthesis steps and analysis steps which the product developers carry out partly consciously, partly also subconsciously.  The aim of this substep is to work out alternative solution variants. V Model  The V model describes the generic procedure for designing Mechatronics systems, which is to be given a more distinct form from case to case  System integration Integration of distributed Modular integration Spatial integration components Components The overall All components such as sensors system is made are spatially and power up of modules of integrated and actuators are defined form a complex connected to one functionality and functional unit, for another via signal standardized example and energy flows dimensions. The integration of all with the aid of coupling takes elements of a communication place via unified drive system systems, that of interfaces such (controller, power the energy flows as for DIN plug actuator, motor, via coupling and and socket transfer element, plug-in connection , operating connectors. standardized element) into a integral. housing. System integration  Assurance of Properties Verification Validation Verification means Validation means testing checking whether the whether the product is way in which something suitable for its intended is realized and whether it purpose or achieves the coincides with the desired value. specification. Validation is the answer Verification is the to the question : Is a answer to the question : right product being Is a correct product developed? being developed? For example, does a software program coincide with the deception of algorithms. 2 Design of an active spring/tilting module Problem Definition:  This example shows the design of an active chassis in railroad technology.  There follows a description of the hierarchical structure and the control.  Improving riding comfort and safety are important requirements for modern rail transportation technology. Conventional rail vehicles are equipped with a passive spring-damper combination and also have poor riding comfort in comparison with today’s vehicle technology.  Faults in the level of the track bed lead to car body oscillations, which impair the riding comfort of the passenger and put safety at risk.  These chassis properties can be improved with the aid of active suspension technology.  High-speed travel over track bends is also to be achieved by the use of an active tilting device. Design of an active spring/tilting module The procedure in the phases of modeling to system analysis when designing an active spring/tilting module  Design of an active spring/tilting module The basic construction of the spring/tilting system Design of an active spring/tilting module Basic construction  By contrast with conventional chassis, it is intended to dispense with all the passive dampers of the secondary suspension of conventional rail chassis.  The car body is connected to the chassis only by means of the pneumatic springs. While the pneumatic spring isolates the vibrations in the upper frequency range, the desired damping in the lower frequency range is realized by adjusting the base point of the pneumatic spring above the upper member.  The disturbances introduced as a result of faults in the level of the track bed can hardly be transferred any longer to the car body and very good riding comfort is achieved.  The information required for controlling the base point adjustment is provided by suitable sensors and processed in a hierarchically constructed multivariable control.  The active tilting device, which permits tilting of the car body into the inside of the curve, can be realized with the same adjusting system. Design of an active spring/tilting module Basic construction  The core structure of the adjusting system comprises the mechanical components of the upper and lower members or the pneumatic spring, the hydraulic actors and the sensors.  While four actors A1, A2, B1, B2 are responsible for lifting and tilting, the other two actors C and D primarily take care of the lateral movement. In this case, the local pitching of the chassis plane is prevented by the actors A1, A2 and B1, B2 and the longitudinal and yawing movements are blocked by lemniscate levers.  As a result, each spring/tilting module actively ensures three directions of movement of vertical, lateral and tilting movements.  The vehicle (comprising two modules) permits all controlled rotational and translatory movements in the lateral and vertical directions. The translatory movement in the longitudinal direction is realized by means of the linear drive. Design of an active spring/tilting module Modeling  In order to investigate the behavior of a dynamic system and subsequently design a multivariable control, first of all the physical substitute model and the mathematical substitute model are formed.  The model is intended to represent the kinematic, static and dynamic behavior of the system to be investigated.  Kinematic functions  The kinematic behavior of the system is determined by the degrees of freedom and the geometry of the spring-tilting module.  Dynamic functions Design of an active spring/tilting module Coordinate systems of the kinematic function  Design of an active spring/tilting module Spatial model for investigating the spring/tilting technique Design of an active spring/tilting module  Mechanical supporting structures  The car body and upper member of the spring/tilting module are modeled as rigid bodies with six degrees of freedom in each case. The elastic properties of the car body are not taken into consideration in this investigation, since the natural frequencies of the first three bending and torsion modes of the car body lie in another frequency range.  Dynamics of the adjusting system  Hydraulic actor systems are used here. The adjusting system principally comprises six differential hydraulic cylinders with five servo valves. The cylinder chambers of the cylinders A1 and A2 are connected in parallel and activated by a valve, while the cylinders B1, B2, C and D are respectively activated separately by a valve. Design of an active spring/tilting module Schematic setup of the hydraulic actor systems Design of an active spring/tilting module  Dynamics of the sensor technology and the digital signal processing  When designing the controller, the dynamic behavior of the sensors used and the dead times occurring with the digital realization of the controller must be taken into consideration in the overall dynamics.  Inductive displacement transducers are selected here as position sensors for sensing the cylinder displacement.  The measurement of the position of each valve slide takes place by means of a position sensor integrated in the servo valve.  Linear potentiometers are used for the measurements of the spring excursions.  The sensors reduce the bandwidth of the system. This effect is modeled by a low-pass filter element. Design of an active spring/tilting module  Dynamics of the complete module  After the aforementioned investigations, the dynamics of the complete module are modeled with a development environment, with the models of all the sub-systems being brought together topologically in the computer with suitable interfaces.  The supporting structure is extended by adding the actors, sensors and digital effects, taking the kinematic interrelation- ships into consideration.  Once the dynamic behavior of the system has been investigated, control structures must be designed, in order that the mechatronic functions of the system achieve the desired system behavior. Design of an active spring/tilting module  Hierarchical system structure  The functional structure of the described system can be used to  ”mechatronic function derive a hierarchy modules“ which is also (MFM), suitable for and the design a of the system of coupled basic modules, the so-called control system. ”autonomous When applied mechatronic to this example, this results system“ (AMS).in a structure comprising mechatronic basic modules, the so-called  The MFM comprise a supporting structure, sensors, actors and local, controlling information processing.  The AMS is constructed from MFM coupled in terms of IT and mechanically. The AMS, which likewise has information processing, undertakes superordinate control tasks, such as for example influencing the structure dynamics of the car body in the sense of a cascade control, and generates  Design of an active spring/tilting module Example of structuring of mechatronic systems  Design of an active spring/tilting module Hierarchization of the overall spring/tilting module and car body system Design of an active spring/tilting module  Hierarchical system structure  the overall system, comprising the spring-tilting module and the car body, can be divided into two hierarchies:  On the AMS level, essentially the position of the construction is monitored,  while on the MFM level the behavior of the individual actors is considered.  The subordinate level can be divided once again into two further levels.  MFM1 contains the position and speed control of the hydraulic actors.  The activation of a valve takes place via a subordinate MFM (MFM2), which controls the position of the valve slide. Design of an active spring/tilting module Hierarchical controller structure Analysis of the controlled system Step response of the overall system Analysis of the controlled system Amplitude spectrum of the lateral acceleration Laboratory trials Concept of the test stand module on a scale of 1 : 5 Design of integrated multicoordinate drives Structures Two-coordinate drive with serial kinematics (Page 99 in VDI standard)  Thank You! 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