Force guidance function

Overview of the Force Guidance Function

Force guidance function creates an operation using force control function, force trigger function, and force monitor function without programming by SPEL+ language.
In the force guidance function, operations are created by the force guide sequence and the force guide object.

• Force Guide Sequence
  It is like a container in which the required force guide objects are aligned in a specific order to execute a specific operation, or part of one.

• Force Guide Object
  You can think of these as specific processes, such as conditional branching, specific motions that include the force control function, and so on.

In the force guidance function, create a specific operation by aligning processes (force guide objects) in a container (force guide sequence). Force guide sequences and force guide objects have the general ones (general force guide sequences and general force guide objects) for users to perform arbitrary actions and tasks. Force guide sequences and force guide objects also have the dedicated ones (system force guide sequences and system force guide objects) for achieving specific tasks.
Force guide sequence and force guide object have properties and results.

• Properties
  Property Value that determines the processing of a force guide sequence or force guide object. Depending on the property setting, different motion can be performed even the force guide object is the same.
• Result
  Value which indicates the execution result of the force guide sequence or force guide object.

Force Guide Sequence

Force guide sequence is like a container that the required force guide objects are aligned in a specific order to execute whole or part of the specific operation.
Force guide sequences consist of general force guide sequences and system force guide sequences.

• General force guide sequence: This sequence is created by adding any general force guide object. Enables user-created operations by arranging force guide objects in sequence. As such, general force guide sequences cannot operate as standalone sequences.

• System force guide sequence: This sequence is used for a dedicated operation. Select the user operation wish to perform and configure in the sequence wizard, then force guide objects are placed automatically based on the settings configured in the sequence wizard. Note that general force guide objects can also be added to a system force guide sequence.

The table below is the list of system sequences:

Name	Description
Paste	Aligns the surface of the held workpiece with the surface of the object and presses it to the specified direction.
ScrewTighten	Tightens screws using an electric screwdriver. After tightening the screws, retightening is also enabled.
HeightInspect	Moves the robot to the specified direction, stops it at the point of contact, measures the height of the object, and inspects it.
Insert	Inserts the workpiece. After inserting a connector, etc., applying force in the direction opposite to the insertion direction to check that the inserted workpiece will not come off is also enabled.

In force guidance function, you can specify the force guide sequence and execute by SPEL+ or GUI.
Property of force guide sequence is a setting that affect to the whole force guide sequence or a process setting when executing the force guide sequence.
Result of force guide sequence displays the result of force guide sequence in [Value].

Force Guide Object

It is like a specific process such as a specific motion including force control function or conditional branching.
In the force guidance function, it is not possible to execute by force guide object only. Always execute as the force guide sequence.
Basically, property of force guide object affect to force guide object. However, property setting of force guide object is restricted depending on the setting of previous object. For example, if connecting force control function of two force guide objects, property setting of the second force guide object will be restricted.
Result of force guide object displays the result of force guide object in [Value].
In the force guidance function, you can create the force guide sequence by combining the following ten general force guide objects and 6 system force guide objects that are automatically arranged in system force guide sequence.

General force guide object

• Contact Object
  Contact object moves the robot to the specified direction until it contacts with an object such as a workpiece, and stops it when contacting with the object.
  This object is used for setting the start position or grasp position of other force guide objects. Even if the workpiece dimension or the grasp position of the workpiece have a margin of error, next motion or the force guide object can be executed stably since the contact position can be detected.

• Relax Object
  Relax object moves the robot to a position where the force to the specified direction will be "0".
  This object is used for safety releasing of pressing status after pressing by Press object or removal of extra force which is applied during assembly. Also, by combining with the hand motions, this object can follow and grasp. Even if the workpiece dimension or the grasp positions of the workpiece have a margin of error, the robot can grasp the workpiece stably without applying extra force.

• FollowMove Object
  FollowMove object moves the robot along with the specified path while following so that the force to the specified direction will be "0".
  This object is used for a move of the fixed path of operation targets such as opening/closing the door. In the case of the position control, the operation targets may get damages since extra force is applied if the path moves. However, FollowMove object controls the applied force to be "0". Therefore, the robot can move operation targets without teaching the accurate path.

• SurfaceAlign Object
  SurfaceAlign object moves the robot to a position where the torque of the rotation direction will be "0" while the robot presses the workpiece to a specified direction. At this time, the workpiece surface grasped by the robot and the surface of the working desk or the workpiece on the working desk is parallel.
  This object is used for positioning during assembly or stable placing of the workpiece. Stable contact status is provided even if the workpiece dimension or the grasp positions of the workpiece have a margin of error.

• PressProbe Object
  PressProbe object presses the workpiece grasped by the robot to the working desk or a workpiece on the working desk. Then, the robot moves along the specified path and stops when a hole or a convex shape is detected.
  This object is used for detection of fitting holes or positioning during assembly. Hole position or a convex shape can be detected stably even if the workpiece dimension or the grasp position of the workpiece have a margin of error. We recommend using this object after the following objects: Contact object SurfaceAlign object Press object.

• ContactProbe Object
  ContactProbe object moves the robot to the specified direction until it contacts with an object such as a workpiece, and detects a position that is moved for a specified distance as a hole. If the robot contacts with an object without moving the specified distance, returns to the start position and changes the position to repeat the contact motion.
  This object is used for the hole position detection of workpiece that is difficult to perform by "PressProbe" such as lead part or connector. Even if the workpiece dimension or the grasp position of the workpiece have a margin of error, the hole position can be detected stably.

• Press Object
  Press object operates the robot to press to the specified direction with the specified force.
  Also, as with Relax object, it is possible to follow another specified direction simultaneously. When executing the Press object without contacting, the robot moves to a direction of the specified force. This object is used for pressing of assembly. Even if the workpiece dimension or the grasp position of the workpiece have a margin of error, the robot can keep a certain force stably.

• PressMove Object
  PressMove object moves the robot along with the specified path while pressing to the specified direction with the specified force.
  Also, as with FollowMove object, it is possible to follow another specified direction simultaneously. When executing the PressMove object without contacting, the robot moves to a direction of the specified force in addition to the specified path. Use this object for pressing, screw driving, or polishing for Peg In Hole or assembly. Even the workpiece dimension or the grasp positions of the workpiece have a margin of error, the robot can move with maintaining the stably force.

• Decision Object
  Decision object changes the force guide object to be executed based on the results of the objects in the force guide sequence.
  This object is used for determination for execution of PressProbe object for Peg In Hole task. This object allows executing the required force guide objects based on the actual motion status of the robot.

• SPELFunc Object
  SPELFunc object specifies a function in SPEL+ language and executes it.
  This object is used when you want to execute functions except the force function such as I/O operations. This object is for advanced-level user.

System Force Guide Objects

• Paste Object
  A Paste object is a force guide object used to align the surface of the work piece being gripped with the surface of a target object, and press in the direction specified.
  You can select whether to perform surface alignment while pressing. Enable this to ensure stable attachment even when there is an error in the workpiece dimensions or workpiece grip position. Paste object success is determined based on success conditions for the force and position set. This object is placed automatically when creating a Paste sequence.

• ScrewTighten Object
  A ScrewTighten object is a force guide object used to tighten screws using an electric screwdriver that allows for I/O operations.
  When tightening, the screw is pressed in the direction of tightening while following so that the force in the direction perpendicular to the axis of rotation of the screwdriver becomes "0". Screw tightening success is determined based on the screw tightening complete signal from the screwdriver, and success conditions for the position set. This object is placed automatically when creating a ScrewTighten sequence.

• ScrewRetighten Object
  A ScrewRetighten object is a force guide object that first loosens a screw that was tightened by an electric screwdriver, and then re-tightens it.
  This object is executed when a screw tightening complete signal is received from the screwdriver before the screw position reaches the screw tightening success position for the ScrewTighten object. This is useful when the screw gets caught, or is otherwise improperly tightened when tightening screws. Screw retightening success is determined based on success conditions for the position set. This object is placed automatically when screw retightening is enabled in a ScrewTighten sequence.

• HeightInspect Object:
  A HeightInspect object is a force guide object that moves the robot in a specified direction, stops it upon contact with an object, and measures and inspects the height of the object it has come into contact with.
  Measuring the dimensions of the workpieces distributed and the height of the workpiece dimensions after assembly allows you to verify whether assembly work has been performed properly. Height inspection success is determined based on success conditions for the position set. This object is placed automatically when creating a HeightInspect sequence.

• Insert Object:
  An insert object is a force guide object used to insert a workpiece with a rough tolerance.
  When inserting, a pressing force is applied while following so that the force perpendicular to the direction of insertion becomes "0". You can also select whether to follow the force in the direction of rotation. Insertion success is determined based on success conditions for the force and position set. This object is placed automatically when creating an insertion sequence.

• TensileTest Object:
  A TensileTest object is a force guide object used after the insertion of a connector or similar workpiece to determine whether it can be removed by applying a force in the direction opposite to its direction of insertion.
  This object is executed when the success conditions for insertion have been met for an insertion object. TensileTest success is determined based on success conditions for the force and position set. This object is placed automatically when tensile tests are enabled in an insertion sequence.