● Spiral

● Sinus

● Lissajous

Commanding the search motion generation:

● Position-based trajectory

● Force-based trajectory

● Combination of position and force-based trajectory

Reduction of arbitrary joining part types to three ab- stract planar types:

Lissajous (force driven motion)

Parts T and P of joining motion with

gear, search: toothed gear joining motion and screw-in motion

● Rectangular (additionally defined workpiece coordi-

nation system)

Strategy of triangular types is common for numerous workpiece contours:

● Orientation is given, tipping is executed in one step; object pivots around one corner

● Meshing in toothed gears: Torque oscillations about gear axis and linear forward motion

● Screw-in motion: fixed torque for torque-based

screwing

● Angle-controlled tightening required in most screw-

ing process applications: command fixed torque, then turn by a defined angular increment。

for Assembly (DFA), workcell and assembly line de- sign as well as logistics and manufacturing organiza- tion [54。12]。 Early on, industrial robots were used in assembly automation, particularly in high-throughput manufacturing lines (Fig。 54。4)。 However, robots are increasingly used in highly flexible workcells and will enter agile lean manufacturing workplaces as versatile tools at the hands of the human worker。 In the follow- ing, selective use cases of robots in assembly will    be

described by detailing on specific enabling technolo- gies。

Assembly of Limb Material

Numerous assembly processes include handling of limb materials such as rubber hoses, wire  harnesses, etc。 that have to be fixed in position in order to be joined (Fig。 54。15)。 Obviously stabilizing the material and securing process quality often result in ingenious grip-

Fig。 54。17 Set up and implementation of a centrifugal clutch assembly for a chain saw with a sequence diagram depicting the consecutive steps until tightening the clutch。 Through the robot’s torque sensors in each of its links and an appropriate kinematic and dynamic model, the resulting forces at the tool tip are controlled

per designs involving additional actuation and sensing functionalities。

An example is the automatic application of self-ad- hesive seals as they easily lose their shape and can be stretched or compressed。 Since manual application of adhesive seals to vehicle bodies or doors is sensitive and ergonomically problematic a robot-guided tool has to secure bonding of the material’s surface to the car body。 The seal material is fed from a roll under correct tension and the tape, which covers the adhesive, is re- moved and stored in a small tank。 At the tip of the tool a laser sensor follows the car body or door contour and an actuated roller produces a continuous normal force on the seal。 Both the laser sensor and roller’s motion are translated into a tension free motion of the robot。 In addition, a magazine on a flange ensures that the  seal is correctly tensioned and a material reserve for one car door is provided [54。47]。

Here, the robot acts as slave to guide a tool which acts as both measuring unit and precision actuator with own master controller。 Further efforts aim at embedding rich sensor and control modalities in the robot to ac- count for complex process control based on tactile and geometric information。