ºÝºÝߣ

ºÝºÝߣShare a Scribd company logo

Mechatronics 05.1

?Download as PPT, PDF?
?
S
Sachin Khedkar

The document discusses several key aspects of mechatronic system design including the design process, types of design, mechanisms, load conditions, flexibility, man-machine interfaces, safety, and distributed control systems (DCS). The design process involves multiple stages including need identification, feasibility analysis, specification, conceptual design, analysis and modeling, embodiment and optimization, detail design. Mechanisms experience various load conditions that must be considered in their design. Both mechanisms and structures require analysis of flexibility and vibration.

1 of 13
Download to read offline
Mechatronics ELS 5304 Ref: Mechatronics : Bradley, Dawson, Burd, Loader
The design process can be split into several stages, each separated by a review and a continue/rework/abort point. a. Need b. Feasibility c. Specification d. Conceptual Design e. Analysis and Modelling f. Embodiment and Optimisation g. Detail Design Ref: Mechatronics : Bradley, Dawson, Burd, Loader Design Process
Types of Design ? Design for function ? Design for strength or stiffness ? Design for reliability ? Design for maintainability ? Design for manufacture Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Mechanisms ? Mechatronic systems require mechanisms for various functions like ¨C Change of speed ¨C Action at a distance ¨C Force amplification ¨C Sequencing ¨C synchronising Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Mechanisms ¨C Load conditions ? A mechanism experiences variety of load conditions at both input and output. ? It has its own inertia due to its motion ? The mechanism driver must be able to provide sufficient force as well as torque to cover the entire operational envelope Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Structures ¨C Load Conditions ? The loading on a structure must be carefully analysed before designing adequate structure. ? The stresses may be difficult to analyse. ? Analysis by computer modelling is helpful. TYPES : * static loading * dynamic and cyclic loading * impulse and shock loading Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Mechanisms ¨C Load conditions Load Conditions decide ? actuator requirements ? attaining partial static balance ? articulation requirements ? speed and accuracy ? minimization of kinetic energy ? power transmission over a distance ? effect of assembly play and friction ? inertia Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Mechanism - Flexibility ? Resilience ¨C each member of mechanism experiences tension, bending and torsion. Allowed loading can be determined by mathematical modelling ? Backlash ¨C flexibility in mechanism causes backlash in gears or play in joints ? Vibration ¨C flexibility in mechanism leads to vibrations in dynamic loading. Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Flexibility of Structures ? Using microprocessors, local flexibility in structures can be taken care of, if we use closed loop control with feedback sensor close to point of action ? If sensors are located far away from the point of action then errors can result due to flexibility of structure. So the structure will have to be designed to be very stiff. (making it heavy, increasing energy requirements of robot) Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Flexibility of Structures ? Vibration Effects - Flexible structures are prone to vibrations, particularly if excited at natural frequencies. ? Materials ¨C suitable choice of material and manufactured form can greatly affect the flexibility and life of structure. Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Man-Machine Interface ? Facility by which bidirectional transfer of information required for system operation takes place ? It is concerned with ergonomic aspects of the design and covers areas such as display of information, operator systems, environmental factors and safety. Ref: Mechatronics : Bradley, Dawson, Burd, Loader
Safety ? Operator Safety Trapping, Entanglement, Contact, Impact, Ejection Environment ? System Safety Shock, Vibration, Corrosion, Fire, Misuse Redundancy Ref: Mechatronics : Bradley, Dawson, Burd, Loader
DCS ? Level 0 contains the field devices such as flow and temperature sensors, and final control elements, such as control valves ? Level 1 contains the industrialised Input/Output (I/O) modules, and their associated distributed electronic processors. ? Level 2 contains the supervisory computers, which collect information from processor nodes on the system, and provide the operator control screens. ? Level 3 is the production control level, which does not directly control the process, but is concerned with monitoring production and monitoring targets ? Level 4 is the production scheduling level. ? Levels 1 and 2 are the functional levels of a traditional DCS, in which all equipment are part of an integrated system from a single manufacturer. ? Levels 3 and 4 are not strictly process control in the traditional sense, but where production control and scheduling takes place. 12/11/17 Ref: Mechatronics : Bradley, Dawson, Burd,

More Related Content

Mechatronics 05.1

  • 1. Mechatronics ELS 5304 Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 2. The design process can be split into several stages, each separated by a review and a continue/rework/abort point. a. Need b. Feasibility c. Specification d. Conceptual Design e. Analysis and Modelling f. Embodiment and Optimisation g. Detail Design Ref: Mechatronics : Bradley, Dawson, Burd, Loader Design Process
  • 3. Types of Design ? Design for function ? Design for strength or stiffness ? Design for reliability ? Design for maintainability ? Design for manufacture Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 4. Mechanisms ? Mechatronic systems require mechanisms for various functions like ¨C Change of speed ¨C Action at a distance ¨C Force amplification ¨C Sequencing ¨C synchronising Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 5. Mechanisms ¨C Load conditions ? A mechanism experiences variety of load conditions at both input and output. ? It has its own inertia due to its motion ? The mechanism driver must be able to provide sufficient force as well as torque to cover the entire operational envelope Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 6. Structures ¨C Load Conditions ? The loading on a structure must be carefully analysed before designing adequate structure. ? The stresses may be difficult to analyse. ? Analysis by computer modelling is helpful. TYPES : * static loading * dynamic and cyclic loading * impulse and shock loading Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 7. Mechanisms ¨C Load conditions Load Conditions decide ? actuator requirements ? attaining partial static balance ? articulation requirements ? speed and accuracy ? minimization of kinetic energy ? power transmission over a distance ? effect of assembly play and friction ? inertia Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 8. Mechanism - Flexibility ? Resilience ¨C each member of mechanism experiences tension, bending and torsion. Allowed loading can be determined by mathematical modelling ? Backlash ¨C flexibility in mechanism causes backlash in gears or play in joints ? Vibration ¨C flexibility in mechanism leads to vibrations in dynamic loading. Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 9. Flexibility of Structures ? Using microprocessors, local flexibility in structures can be taken care of, if we use closed loop control with feedback sensor close to point of action ? If sensors are located far away from the point of action then errors can result due to flexibility of structure. So the structure will have to be designed to be very stiff. (making it heavy, increasing energy requirements of robot) Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 10. Flexibility of Structures ? Vibration Effects - Flexible structures are prone to vibrations, particularly if excited at natural frequencies. ? Materials ¨C suitable choice of material and manufactured form can greatly affect the flexibility and life of structure. Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 11. Man-Machine Interface ? Facility by which bidirectional transfer of information required for system operation takes place ? It is concerned with ergonomic aspects of the design and covers areas such as display of information, operator systems, environmental factors and safety. Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 12. Safety ? Operator Safety Trapping, Entanglement, Contact, Impact, Ejection Environment ? System Safety Shock, Vibration, Corrosion, Fire, Misuse Redundancy Ref: Mechatronics : Bradley, Dawson, Burd, Loader
  • 13. DCS ? Level 0 contains the field devices such as flow and temperature sensors, and final control elements, such as control valves ? Level 1 contains the industrialised Input/Output (I/O) modules, and their associated distributed electronic processors. ? Level 2 contains the supervisory computers, which collect information from processor nodes on the system, and provide the operator control screens. ? Level 3 is the production control level, which does not directly control the process, but is concerned with monitoring production and monitoring targets ? Level 4 is the production scheduling level. ? Levels 1 and 2 are the functional levels of a traditional DCS, in which all equipment are part of an integrated system from a single manufacturer. ? Levels 3 and 4 are not strictly process control in the traditional sense, but where production control and scheduling takes place. 12/11/17 Ref: Mechatronics : Bradley, Dawson, Burd,