NX 10 mechatronics concept design

NX 10 mechatronics concept design.........................................................................................................................................................................................................................................................

Mechatronics Concept Designer

What is it?

Mechatronics Concept Designer is an application that you use to simulate the complex motion of mechanical systems interactively It is designed to support the early machine design phase that provides the basic machine concept including the mechanical, electrical, fluid, and software aspects It is a solution that transforms the machine creation process into

an efficient mechatronics design approach

This application is built on the following principles:

Functional machine design

One of the main instruments in this is the functional model, which forms the foundation to provide an interdisciplinary view of the mechatronics system machine It lets you lay the foundation for collaboration in detailed design by supporting the early design phase with a functional design approach

The functional model provides the link between the data management of the different disciplines and the requirements This enables the traceability of the customer demand data down to the design departments Further, the functional model provides a supporting

structure to come up with initial design concepts and has the features to perform an

evaluation of design alternatives

Early system validation

Mechatronics Concept Designer introduces a verification technology that is built on a new simulation engine It helps validate concept designs at a very early stage of the

development process

Multidisciplinary support

Mechatronics Concept Designer facilitates interdisciplinary concept design up front The following disciplines can jointly work on a project:

 Mechanical engineer creates the design based on 3D shapes and kinematics

 Electrical engineer help select and position sensors and actuators

 Automation programmer designs the basic logical behavior of the machine He starts with time based behavior and then defines the event based control

Modularity and reuse

Mechatronics Concept Designer provides the ability to capture knowledge in components and store them in a library to enable the reuse of this knowledge in other projects Since the

library components are based on already proven concepts, it improves the design quality and speeds up development

Mechatronics Concept Designer supports the definition of functional units such as those in the VDW Standard Funktionsbeschreibung

Where do I find it?

Application Mechatronics Concept Designer

Mechatronics Concept Design workflow

The following represents a typical machine design workflow using Mechatronics Concept Designer:

1 Define and manage design requirements

o Gather and structure requirements

o Add derived requirements

o Link requirements to each other

o Add more details to requirements using embedded tools like Microsoft Word

2 Create a functional model

o Define basic functions of the system

o Create a hierarchy based on a functional decomposition

o Create and maintain alternatives for the functional design

o Reuse functional units

3 Create a logical model

o Define the basic logical model of the system

o Create a hierarchy based on the logical decomposition of the system

4 Create tracelinks between the functional model and the logical model

5 Define the mechanical concept

o Define a rough 3D outline of the basic solution concept

o Assign mechanical implementation objects to functional and logical tree

o Add kinematics and dynamics

6 Add basic physics and signals

o Add basic physics and speed constraint and position constraint actuators

o Add signal adaptors

o Assign signal adaptor object to function and logical tree

7 Define time based operations

o Define how the actuators are controlled by operations

o Arrange the sequence of operation with a time based notion

o Assign operations to the corresponding functions in the function tree

o Assign operations to the corresponding logics in the logical tree

8 Add sensors

o Add sensors that are triggered by collisions of system elements with sensor objects, or sensors that are defined by a signal adapter

9 Define event based operations

o Define operations that are triggered by events that are generated by sensors

or other objects in the mechatronics systems, such as the position of an actuator

o Assign operations to the corresponding functions in the function tree

10 Replace concept model with detailed model and transfer physics objects from the rough geometries to the detailed ones

11 Align sensors and actuators with ECAD

12 Export sequence of operation in PLCOpen XML format to a PLC engineering tool like STEP 7

13 Test PLC program via OPC connection

Identify mechatronics tool bars and navigators

You will use multiple tool bars, navigators, groups and commands in this course Use this topic to identify them properly and navigate through course instructions

Main tool bar

The main tool bar refers to the tabs along the top of the NX window Tabs include:

In this course, you will be directed to main tool bar functions with the following direction:

 Choose File→All Applications→Machine Tool Builder

Mechatronics tool bar

The Mechatronics tool bar is used to divide commands into groups based on their function Mechatronics groups include:

 Systems Engineering Use this group to apply requirements, functions, logical models, and dependencies

 Mechanical Concept Use this group to add or change model features

 Simulate Use this group to start and control simulations in mechatronics

 Mechanical Use this group to apply physics features to models

 Electrical Use this group to apply electrical features that are active during

In this course, you will be directed through groups with the following direction:

 Choose Home tab→Design Collaboration group→Replace Component

Resource bar

The Resource bar is the set of tabs located along the edge of the NX window The tabs displayed on the bar vary depending on your specific configuration and active application The resource bar is divided into four main categories:

1 Navigators

2 HD3D Tools

3 Integrated Browser Window (Windows only)

4 Palettes

Tabs commonly used in mechatronics include:

 System Navigator Use the System Navigator tab to view the requirements, functional and logical models of a product You can use the System Navigator to attach dependent objects that help navigate across the requirements, functional, logical models and the physical representations such as mechanical components, electrical devices, operations or physics objects Expanded functionality is available when using NX in Teamcenter Integration mode

 Physics Navigator Use the Physics Navigator tab to display the physical and logical properties of mechanical elements

 Runtime Expression Use the Runtime Expression tab to view expressions that you created to apply equations, ratios and relationships between physics

of operations, similar to sequential function logic

On the Resource Bar, choose Sequence Navigator

Activity: Run a simulation and monitor values

Estimated time to complete: 5-10 minutes

In this activity, you will use simulations to apply physics properties and motion to

mechatronics models You can monitor motion and values that are introduced using actuators, mechatronics signals, and external signals You will use runtime simulation and runtime inspector to run simulations and monitor values You will apply basic simulation commands including:

 Play

 Pause

 Stop

 Restart

Run a simulation

You will use simulation commands to simulate a robotic cell in Mechatronics Concept Designer

1 Open mcd01_training_plant_e

2 Choose File tab→All Applications→Mechatronics Concept Designer

3 Choose Home tab→Simulate group→Play

When the simulation is active, physics and motion characteristics that have been assigned become active If the simulation is active, many Mechatronics Concept Designer commands are unavailable

4 Choose Home tab→Simulate group→Stop

Notice that when the simulation is stopped the geometry returns to the positioning established in the model

5 Play the simulation and while it is running, in the Simulate group, select Restart

The simulation returns to the positioning established in the model and immediately begins moving again

6 In the Simulate group, select Pause

If the simulation is paused, it is still considered to be running Stop the simulation to access all of the mechatronics commands

7 Stop the simulation

Monitor simulation values

Use the runtime inspector to monitor the values of physics objects

1 Choose Home tab→Simulate group→Play

2 In the Simulate group, click Runtime Inspector

3 In the Physics Navigator, in the Sensors and Actuators group, select arm motor The runtime inspector dialog box lists the characteristics of the selected object

4 Verify the motor speed in the Runtime Inspector dialog box

5 To pause the simulation and view the current values, in the Simulate group, click Pause

6 Click Stop

Set simulation preferences

Use the runtime inspector to monitor the values of physics objects

1 Choose File tab→All Preferences→Mechatronics Concept Designer

2 Click the Physics Engine tab

3 In the Runtime Parameters group, set the following:

o Collision Precision = 3

o Step Time = 0.1

4 Click OK

5 Run the simulation to see the results and then stop the simulation

Adjusting the preference values for the simulation can have either positive or negative results In this activity, the adjustments are detrimental Use these

parameters to optimize a simulation that does not run smoothly The step time is a refresh rate for updating the model The collision precision value adjusts the accuracy of the collision shapes

6 Return the values to the default values:

o Collision Precision = 0.0039 inches

o Step Time = 0.001

7 Run the simulation to see the results and then stop the simulation

8 Close the file without saving

You completed the activity

Use joints to direct motion

Use joints to create motion restrictions between pieces of geometry You can create joints with force and torque limitations You can use the following joints:

Hinge joint

Use the Hinge Joint command to create a joint between two bodies that allows one

rotational degree of freedom along an axis A hinge joint does not allow translational movement in any direction between the two bodies

Sliding joint

Use the Sliding Joint command to create a joint that allows one translational degree of freedom between two bodies along a vector A sliding joint does not allow the bodies to rotate with respect to each other

Cylindrical joint

Use the Cylindrical Joint command to create a joint between two bodies that allows two degrees of freedom: one translational and one rotational With a cylindrical joint, the two bodies are free to rotate and translate relative to each other about and along a vector

Ball joint

Use the Ball Joint command to create a joint between two bodies that allows three

rotational degrees of freedom Ball joints are also known as spherical joints

Fixed joint

Use fixed joints to attach geometry to the coordinate system or to another piece of geometry Use fixed joints when you do not want motion between objects such as weld joints

Activity: Apply gravity and motion restrictions

Estimated time to complete: 15-23 minutes

In this activity, you will apply gravity to objects in a model You will use joints to restrict the motion of geometry You will use the following:

 Choose File tab→All Applications→Mechatronics Concept Designer

 On the Resource bar, select the Physics Navigator

Note This will display the features you are about to add

 Choose Home tab→Simulate group→Play

Note Several commands become unavailable when you play the simulation Currently, there are no physics properties applied to this model so no motion is displayed

 Choose Home tab→Simulate group→Stop

 Choose Home tab→Mechanical group→Rigid Body

 In the graphics window, select Solid body in MCD01_PLANT FLOOR

When you hover the mouse over a group of features in the graphics window, the icon

changes to If you left-click with this icon, a list of nearby features appears for you to choose from The list is referred to as QuickPick

 In the Mass and Inertia group, verify that Mass Properties are set to Automatic

 In the Name group, type plant floor

 Click OK

 Play the simulation

Notice that by applying the rigid body to the plant floor geometry is now affected by gravity

 Stop the simulation

The plant floor has returned to the original coordinate system

 Repeat steps 6 through 10 and use the table and image to name the geometry as follows:

Note  Do not assign a rigid body to item 8

 Click Apply to create an object without closing a dialog box

 Run the simulation to see the results and then stop the simulation

Notice all of the assigned geometry is now affected by gravity

Prevent floors and surfaces from falling

To prevent a rigid body from falling you need to create a fixed joint Fixed joints can be used to:

 Fix geometry in the coordinate system

 Attach two pieces of geometry and not allow movement

1 Choose Home tab→Mechanical group→Fixed Joint

2 In the Rigid Bodies group, highlight Select Attachment

3 In the graphics window, select Rigid Body: plant floor

Note Do not select a base for this example

4

5 In the Name group, type floor bolts

6 Click OK

7 Run the simulation to see the results and then stop the simulation

The plant floor is now fixed in the coordinate system and will not fall due to gravity The falling objects will pass through the floor until the collision body command is used later

8 Repeat steps 1 through 4 and name the fixed joints as follows:

9

10 Run the simulation to see the results and then stop the simulation

The conveyors and floor remain in place All other components are affected by gravity and pass through the fixed objects

Fix model components together

Use the fixed joint command to connect geometry In the fixed joint dialog box, assign both

an attachment and a base object to link the pieces together

1 Choose Home tab→Mechanical group→Fixed Joint

2 In the Rigid Bodies group, highlight Select Attachment

3 In the graphics window, select Rigid Body: robot base

4 In the Rigid Bodies group, highlight Select Base

5 In the graphics window, select Rigid Body: plant floor

6 In the Name group, type robot bolts

7 Run the simulation to see the results and then stop the simulation

The rigid bodies robot base and plant floor are now physically linked together

Create rotational motion joints

Use a hinge joint to create rotating joints The motion of the joint is restricted to rotating around a single axis that you select You will create hinge joints for the robot arms in the model

1 Choose Home tab→Mechanical group→Hinge Joint

2 In the Rigid Bodies group, highlight Select Attachment

3 In the graphics window, select Rigid Body: long arm

4 In the Rigid Bodies group, highlight Select Base

5 In the graphics window, select Rigid Body: robot base

6 In the Axis and Angle group, use the Specify Axis Vector drop-down to select XC

7 In the Axis and Angle group, highlight Specify Anchor Point

8 In the graphics window, select the center point of the hole in long arm

9 In the Name group, type base joint

10 Click OK

11 Run the simulation to see the results and then stop the simulation

The motion of the long arm is now restricted to revolving around the joint axis

12 Repeat steps 1 through 10 to create a second hinge joint Use the following:

o In the Rigid Bodies group, set short arm as the attachment and long arm as the base

o In the Axis and Angle group, set the Axis Vector to XC and set the Anchor Point to the center point of the hole in long arm

o Name the joint arm joint

13 Run the simulation to see the results and then stop the simulation

Both robot joints are limited to rotational motion Gravity will still cause the joints

to collapse until you add actuators in the next lesson

Create linear motion joints

Use a sliding joint to create a joint that is restricted to linear motion along one axis

1 Choose Home tab→Mechanical group→Sliding Joint

2 In the Rigid Bodies group, highlight Select Attachment

3 In the graphics window, select Rigid Body: bin

4 In the Rigid Bodies group, highlight Select Base

5 In the graphics window, select Rigid Body: plant floor

6 In the Axis and Offset group, highlight Specify Axis Vector, use the Specify Axis Vector drop-down to select XC

7 In the Name group, type bin track

8 Click OK

9 Run the simulation

10 Drag and drop the bin to verify its motion is restricted to motion in the X direction

11 Stop the simulation

12 Close the part without saving

You completed the activity

Understanding collision bodies

Use a collision body to define how a piece of geometry will collide with other elements that also have a collision body Objects without a collision body pass through other objects

Collision Shapes

Mechatronics Concept Designer provides calculations of collisions using simplified

collision shapes The greater the geometric accuracy of the collision shape also results in the body being more prone to penetration failures In order to reduce the risk of instability (passing through, stickiness, jittering) and maximize the runtime performance it is

recommended to use the simplest collision shape possible You can use the Convex Factor slider in the Collision Body dialog box to further enhance the detail of the collision body The following collision shapes are available:

Activity: Make objects collide during simulations

Estimated time to complete: 10-15 minutes

In this activity, you will assign collision bodies to geometry that should interact You will change collision shapes to adjust how the collision body is physically represented when simulations are running

Make geometry collide

1 Open mcd01_training_plant_b

2 Choose Home tab→Mechanical group→Collision Body

3 In the graphics window, select Solid Body in MCD01_PLANT FLOOR from the QuickPick options

4 Set the following

o Shape group

 Collision Shape = Box

o Collision Material group

 Material = Default Material

o Category group

 Category = 0

o Highlight on Collision group

 Highlight on Collision = Note When you open a dialog box it will be displayed however it was last closed

If you do not see all of the groups, click More to fully expand a dialog box

5 In the Name group, type plant floor

6 Click Apply

7 Repeat steps 1 through 8 and name the collision bodies as follows:

For geometry with mesh collision shapes, set Convex Factor = 1.00 The Convex Factor slider is used to further enhance the detail of the collision body

Part

Note When you use QuickPick in the graphics window, be sure that you select the

solid geometry and not just a face of the geometry

8 Click OK

9 Run the simulation to see the results

The geometry with a collision body assigned will contact other surfaces and prevents objects from passing through each other

10 With the simulation still running, left-click rectangle part to drag it to a different location to see how it interacts with the other collision bodies

11 Stop the simulation

12 Close the part

You completed the activity

Use actuators to move geometry

Actuators

To apply actuators in a model, you must assign them to joints that you already created You can apply virtual actuators to linear and rotational joints Use actuators to move geometry at specific speeds or a specific distance Use two different types of actuators to achieve the desired motion:

 Position Control actuator: You will use this actuator to rotate geometry a specific distance and then stop

 Speed Control actuator: You will use this actuator to make geometry move at a specified speed indefinitely

Transport Surface

Use a transport surface to apply motion to a geometric plane You can use transport

surfaces to move other parts in the model Set the transport speed and direction to dictate motion characteristics

Activity: Apply motion with actuators and transport

surfaces

Estimated time to complete: 10-15 minutes

In this activity, you will use actuators to move linear and rotary joints You will use

transport surfaces to simulate conveyor belts and move parts

Start the activity

Apply motion with rotational actuators

1 Open mcd01_training_plant_c

2 Choose Home tab→Electrical group→Position Control

3 In the Axis Joint, highlight Select Axis Joint

4 In the graphics window, select Hinge Joint: base joint

5 In the Constraints group:

o Angular Path Options = Rotate Counter-clockwise

o Destination = 75 degrees

o Speed = 30 degrees/sec

6 In the Name group, type base motor

7 Click OK

8 Run the simulation to see the results and then stop the simulation

The long arm now moves counter-clockwise 75 degrees

9 Choose Home tab→Electrical group→Speed Control

10 In the Axis Joint box, highlight Select Axis Joint

11 In the graphics window, select Hinge Joint: arm joint

12 In the Constraints group, set the Speed to 75 degrees/sec

13 In the Name group, type arm motor

14 Click OK

15 Run the simulation to see the results and then stop the simulation

The short arm rotates at a constant speed indefinitely

Apply motion with linear actuators

Apply a position control actuator to a sliding joint to produce linear motion Use the

actuator to move the bin geometry parallel to a single axis The actuator will move the bin a specified distance and then stop

1 Choose Home tab→Electrical group→Position Control

2 Do the following:

o Axis Joint group

 Highlight Select Axis Joint

 Axis Type = Linear

 In the graphics window, select Sliding Joint: bin track

3 Set the following:

5 Run the simulation to see the results and then stop the simulation

The bin moves towards the end of the long conveyor and stops

Create conveyor belts

You will use transport surface to create two conveyor belts You will assign transport surfaces to the faces of the geometry that you want to act as conveyors Use the conveyors

to move a part down the basic assembly line

1 Choose Home tab→Mechanical group→Transport Surface

2 In the Conveyor Face group, highlight Select Face

3 In the graphics window, select the top face of the MCD01_SHORT CONVEYOR

4 In the Velocity group, set the following:

o To set the vector direction, set Specify Vector to YC

o Parallel = 5 in/sec

5 In the Name group, type short conveyor and click OK

6 Run the simulation to see the results and then stop the simulation

7 Choose Home tab→Mechanical group→Transport Surface

8 In the Conveyor Face group, highlight Select Face

9 In the graphics window, select the top face of MCD01_LONG CONVEYOR

10 In the Velocity group:

o Specify Vector = XC

o Parallel = 5 in/sec

11 In the Name group, type long conveyor and click OK

12 Run the simulation to see the results and then stop the simulation

The surfaces are now conveyor belts and move the rectangle part down the

simulated assembly line The robot arm will position over top of the long conveyor and the short robot arm will rotate to push the rectangle part into the bin

Note If the short arm is rotating in the wrong direction, in the physics navigator, under the joints and constraints folder, open the arm joint In the axis and angle group, use Reverse Direction to reorient the joint

13 Close the part without saving

You completed the activity

Activity: Create joints with a physical limitation

Estimated time to complete: 3-5 minutes

You will use a breaking constraint to create a joint with a maximum force limitation The joint will fail when the geometry collides and the maximum force is exceeded You will also change the mass characteristics of a rigid body

Start the activity

Create a joint that will break

1 Open mcd01_training_plant_d

2 In the Physics Navigator, under the Basic Physics group, double-click the rigid body rectangle part

3 To increase the mass of the rectangle part, in the Mass and Inertia group set:

o Mass Properties = User Defined

o Mass = 1000

4 Click OK

5 Run the simulation to see the results and then stop the simulation

The robot arm is not affected by the part’s change of mass The part is pushed into the bin

6 Choose Home tab→Mechanical group→Breaking Constraint

7 In the graphics window, select Hinge Joint: arm joint

8 In the Constraints group, set Maximum Magnitude to 110

9 In the Name box, type arm constraint

10 Click OK

11 Run the simulation to see the results and then stop the simulation

The force required to push the rectangle part into the bin is greater than the breaking constraint The joint is broken and the short arm falls to the floor

12 Close the part without saving

You completed the activity