By using the kinematic elements you can already create multi-bar systems of infinite complexity and variety. Additionally, though, ASOM v7 also offers you syntheses for some of the most popular multi-bar linkage types.
Syntheses aid you in the design of multi-bar linkages based on a description of the desired movement. This description can be given in the form of desired points or planes (point plus orientation) for start and end of the movement (and sometimes in between).
One-Bar
With this synthesis you can construct a one-bar mechanism that moves one given point onto another.
With this synthesis you can construct a one-bar mechanism that moves one given point first onto a second and then onto a third.
With this synthesis you can construct a one-bar mechanism that moves one given plane onto another.
Four-Bar
With this synthesis you can construct a four-bar mechanism that moves one given point onto another.
With this synthesis you can construct a four-bar mechanism that moves one given plane onto another.
With this synthesis you can construct a four-bar mechanism that moves one given plane first onto a second and then onto a third.
Six-Bar
With this synthesis you can construct a six-bar mechanism of the configuration Stephenson (I) that moves one given plane onto another.
With this synthesis you can construct a six-bar mechanism of the configuration Stephenson (IIa) that moves one given plane onto another.
With this synthesis you can construct a six-bar mechanism of the configuration Stephenson (IIb) that moves one given plane onto another.
With this synthesis you can construct a six-bar mechanism of the configuration Stephenson (III) that moves one given plane onto another.
With this synthesis you can construct a six-bar mechanism of the configuration Watt (Ia) that moves one given plane onto another.
With this synthesis you can construct a six-bar mechanism of the configuration Watt (Ib) that moves one given plane onto another.
Crank Slider
With this synthesis you can construct a crank-slider mechanism that moves one given plane onto another.
With this synthesis you can construct a crank-slider mechanism that moves one given plane first onto a second and then onto a third.
With this synthesis you can construct a crank-slider mechanism that moves in an exactly straight line between two given points.
With this synthesis you can construct a crank-slider mechanism that moves in an approximately straight line between two given points.
Force Synthesis
The force synthesis allows you to set certain holding force values at certain simulation times (or situations) and then keep them fixed.
Kinematic elements are the basic components that allow you to build a kinematic system. Their main function is to transmit movement, and for this they can be fitted with drives. They can also transmit forces, but they cannot be moved by forces.
A bar is a rigid kinematic element with two joints (binary link). Even though it is depicted by default as just a straight line, it can functionally represent any element of arbitrary shape that shares these basic properties.
A prismatic pair consists of two elements: the slider and the guide. The slider is equipped with a joint and can slide along the guide, which itself can be rotated around a joint at one of its ends.
Like the prismatic pair, the curved guide also consists of a slider and a guide. The guide can be curved here though, since it is represented by a spline. The joint of the guide is connected to the guide by a rigid extension, the length of which can be set to zero though, if necessary. The joint of the slider, on the other hand, is situated directly on the slider. The guide can also be laid out as closed loop and even cross itself.
Gear pairs transmit a rotary motion, while reversing its direction and often changing its speed. During creation you will first have to choose the position of the joints the gears should be mounted on, followed by the gears’ point of contact. Depending on these inputs, the transmission ratio is computed.
Like the gear pair, the belt transmission is used to transmit a rotary motion, in this case by using a belt, though. This means that after its creation you can decide if you want to change the direction of the motion by crossing the belt, if the belt should be closed and, if not, if it should be brought around the other side of each wheel.
The rack-and-pinion converts the rotary motion of a gear into a translatory motion of a rack. It consists of three parts: pinion (gear), housing, and rack. Additionally it has two joints: one for the pinion and one on the rack.
The floating bearing limits a joint’s movement to a straight line. It can move any distance in either direction, but it will not be able to deviate from the straight line. The direction of the straight line cannot change during a simulation.
With a fixed bearing you can fix a joint in place. Elements connected to it can still rotate around the joint, but the joint itself can no longer change position.
With the fixed angle, you can keep the angle between two elements connected by a joint constant. With this element you can also merge two separate binary links (with two joints each) to become one single trinary link (with three joints). This merging into a rigid body can be extended to an arbitrary number of elements.
With drives you can impose a motion onto a kinematic element. They can be used on a variety of couplers, but do not exert any force of their own, just the pure motion. To make a kinematic system capable of simulation, you need at least as many drives as the number of degrees of freedom in the whole system. If more drives than degrees of freedom are placed, no more than the number of the degrees of freedom may be active at the same time.
The absolute rotary drive imposes a rotational movement on the coupler it is placed on.
With the relative rotary drive you can make two elements that are connected by a joint rotate against each other.
A free rotary drive moves any two couplers in relation to each other. For the creation it is insignificant whether these couplers are somehow connected or even part of the same linkage.
The absolute linear drive causes a joint to move into the direction that is given by its arrow.
With the relative linear drive you can make a floating bearing move in its given direction or a slider along its guide.
To aid you in precisely positioning your elements, you can make certain points (and other elements) on the Canvas ‘catchable’. Point-like elements, when you create them or while you are moving them around, will snap to those points and take their coordinates, if you move your cursor close to them.
One possibility is to catch on the grid. This means snapping to the grid’s intersections.
Another option is to catch defining points (meaning end or corner points) of elements on the Canvas.
With this command you will be able to catch the exact intersection points of elements on the Canvas.
This command helps you catch the center points of elements on the Canvas. This includes centers of segments of elements (like the sides of a polygon) as well as the centers of circles, gears and wheels.
Alternatively, you can snap to arbitrary points on the contours of elements on the Canvas.
In ASOM v7 you can plot any values from the simulation against each other and let them be visualized in a graph. Any graph is part of a diagram window. In ASOM v7 you can use many predefined graph types to quickly visualize your data. These default graphs always plot a certain quantity over the simulation time.
This graph type differs from all other graphs by not pre-selecting any sources for the x- and y-axes. You can freely select the source for the values of each axis.
The current distance of a point in [mm] from its starting location, measured over the whole duration of the simulation.
The velocity of a point in [mm/s], measured over the whole duration of the simulation.
The acceleration of a point in [mm/s²], measured over the whole duration of the simulation.
The rotation of an element in comparison to its start position in [°], measured over the whole duration of the simulation.
The angular velocity of an element in [°/s], measured over the whole duration of the simulation.
The angular acceleration of an element [°/s²], measured over the whole duration of the simulation.
The vector between two selected points in [mm], measured over the whole duration of the simulation.
The angle between two vectors (each defined by selecting two points) in [°], measured over the whole duration of the simulation.
The length of the path in [mm] a point covers in global coordinates during the simulation (moving along its trajectory).
The lever arm in [mm] for a connection point of a linear force element (or a mass or manual force), measured over the whole duration of the simulation. The lever arm is the distance of the instantaneous center of rotation of the element connected to the chosen connection point to the line of action of the force element.
The stroke of an energy storage (difference between the length of the energy storage in the unstressed and the current state) in [mm], measured over the whole duration of the simulation.
The stroke path length represents the sum of the absolute changes in stroke of an energy storage element in [mm] over the whole duration of the simulation (comparable to Path Length).
The relative ball stud orientation can only be measured for energy storage elements that can be connected by way of ball joints. It corresponds to the oriented angle beta in [°] that is formed by the two studs of the two ball joints of the chosen energy storage element, after they are projected onto a plane that is perpendicular to the axis of the energy storage element, which is then viewed from the direction of the gas spring rod.
The ball stud angularity can only be measured for energy storage elements that can be connected by way of ball joints. It corresponds to the angle alpha in [°], that the direction vector of the chosen ball stud of the chosen energy storage element forms with a plane that is perpendicular to the axis of the energy storage element.
The force exerted by a force element (Force Vector, Gas Spring, …) in [N] over the whole duration of the simulation.
The torque exerted by a torque element (torque, torsion spring) in [Nmm] over the whole duration of the simulation.
The force measured by a manual force or holding force vector in [N] over the whole duration of the simulation.
The torque measured by a holding torque in [Nmm] over the whole duration of the simulation.
The force in [N] acting on a joint by way of a connected element, dependent on a given holding force, measured over the whole duration of the simulation.
The combined force in [N] acting on a joint by way of two connected elements forming a rigid unit, dependent on a given holding force, measured over the whole duration of the simulation.
The component of a joint force acting on a bar, which acts exactly in the direction of the bar, in [N], dependent on a given holding force, measured over the whole duration of the simulation.
Forces
ASOM v7 offers you a variety of options for representing real forces in your system.
By using a mass together with a kinematic element you can simulate the weight and inertia of a real body by placing it at the body’s center of mass.
The absolute torque serves to simulate a torque that supports or hinders the rotation of an element.
A rotational force that acts between two elements can be simulated with a relative torque. It is created by selecting two elements that are connected with a joint.
The force vector will simulate any linear force that acts upon a coupler from or into a certain direction or between two couplers.
Energy Storages
Energy storages are generally supplementary parts that (in the real world) support the movement of a system.
A gas spring is a pneumatic spring that builds up force by compressing gas within its cylindrical body. This makes the exerted force highly reliant on the properties of the used gas. This behaviour can be simulated in ASOM v7 by choosing one from several available ideal or real gas laws.
The pressure spring builds up force by being compressed and will thus exert a counter pressure.
The tension spring on the other hand gathers force by being pulled apart. Consequently, it will exert a counter pull.
The torsion spring operates by enacting force upon its flanks which is retained in the torsion of its coils. It can only be created by selecting two elements that are connected by a joint.
A spindle drive consists of a rod that is located within a cylinder and can be extended or retracted by the use of an internal motor. They often contain an additional spring to support the movement in one direction.
With holding forces you can measure the forces required to counterbalance all known (active) forces in your system.
The manual force measures the force a human would have to exert (manually) at a certain point to balance out all other forces in the system.
With the holding force vector you can measure a force that is enacted linearly.
The absolute holding torque serves to measure a torque that acts on a single element.
With the relative holding torque you can measure a force that acts between two elements that are connected by a joint.
Import
Besides the creation of internal graphical elements you can also load externally created images, DXF files, point positions or splines onto the Canvas. There they can, for the most part, be transformed and connected to kinematic systems like other graphical elements.
This feature imports an image file into your ASOM v7 project. Image files can be imported if their format is PNG or JPG.
This feature imports a DXF file into your ASOM v7 project. The file will be imported as a 2D drawing, according to its native placement and scale. During the import, all numerical values in the file will be interpreted as having the unit [mm].
If you have stored the positions of several points as pairs of x- and y-values in an Excel or text file, you can import these into ASOM v7, to create either a point cloud, or an open or closed polygon on the Canvas.
This feature allows you to import rails for curved guides (splines) from an external source (a text file or Excel file) which contains a description of the spline rail by way of a list of control points.
Export
You have several options to export data from ASOM v7. Only the point export is realized as menu feature, though. Additionally, you can export diagram data and expression results (as well as expression source code).
With this feature you can export the coordinates of point-like elements from the Canvas at arbitrary instants or over the whole of the simulation into a text file, Excel file or DXF file.
Normal Force Dependent Friction
The following friction elements allow you to add variable friction that is dependent on (and consistent with) current normal forces acting on rotary joints or sliding joints. For rotary joints this is joint friction dependent on joint forces, for sliding joints this is slider friction dependent on slider normal forces. Just define a coefficient of friction (and for rotary joints the joint pin diameter) and ASOM calculates the friction accordingly.
With this feature you can create a joint friction element for a rotary joint. It will take a joint force from one bar and use that to generate friction between this bar and one other.
With this feature you can create a joint friction element (from pair) for a rotary joint. It will take a summated joint force from two bars and use that to generate friction between these bars and one other.
With this feature you can create a joint friction element (for wheel) for a rotary joint. It will take a joint force from one bar and use that to generate friction between this bar and a virtual wheel rolling on a curved guide.
With this feature you can create a slider friction element. It will take a normal force from a slider/rail pairing and use that to generate a friction force between slider and rail.