Automated labeling applications demand fast motion, precise positioning, and gentle contact with the product surface. ORCA™ Series Smart Linear Motors combine high-speed linear actuation with built-in force control, allowing machines to transition seamlessly from rapid approach to compliant pressing. This enables reliable and repeatable label application while reducing mechanical complexity and improving overall system performance.
A similar approach can also be used in other applications that involve pressing such as stamping or processes that require applying a specified force for a defined duration.
ORCA motors provide several modes of operation optimized for different use cases. The presented application makes use of Haptic Mode, which allows multiple haptic effects (springs, dampers, oscillations) to be layered together to create complex dynamic behavior. This mode is particularly effective in applications where there is variability in position or timing. See the Haptic Mode Tutorial to get familiar with this mode.
The example described here uses an ORCA motor in an application requiring fast motion (high cycle time) while simultaneously maintaining gentle contact with the package surface.
The system operates as follows:
This is configured as a high-gain single-direction spring used to slow the shaft near the home position.
This soft stop prevents the shaft from striking physical stops such as shaft collars or other mechanical components.
Spring A defines a stable equilibrium at the home position, minimizing the power required to hold the shaft in place.
This spring acts as a soft stop at the opposite end of travel. If the motor cycles without a package present, Spring B prevents the shaft from contacting mechanical hard stops.
This spring is used to create the fast movement, slingshotting the shaft through the fast travel zone. This spring will be used to implement a section of travel with a constant force, creating a controlled acceleration region. This is done by using a very high gain and setting a saturation value. The saturation value becomes a system tuning parameter to determine how fast the shaft accelerates through the fast travel zone. The spring is one sided and ends where deceleration to the controlled approach speed will begin.
The damper effect interacts with the applied Constant Force to determine the steady-state approach speed.
The damper gain combines with the applied force according to:
This relationship determines the constant approach velocity.
The Constant Force effect is used at runtime to trigger transitions between system states.
Set the Constant Force to the desired detect or pressing force.
The actuator cycle uses two primary states in addition to the initial auto-zero procedure during startup.
This state retracts the shaft and also acts as the idle state while waiting for the next cycle trigger.
In this state:
Spring A then compresses until equilibrium is reached when:
For motor_position < spring_A_position
The system stabilizes at this point, resting at the home position.
The return_home_force must be large enough to overpower both the damper and Spring C while in the Fast Travel Zone.
In the APPLY state, the Constant Force is switched from the return_home_force to apply_force.
At this point:
This produces a rapid movement through the fast travel zone.
When the shaft reaches the end of Spring C, the remaining dynamics are:
system inertia
The damper produces a steady approach speed where:
The shaft continues downward at this constant speed until it contacts the package.
At contact:
This becomes the applied pressing force.
Once contact is detected, the system can:
Reliable detection cannot rely solely on force measurements.
Instead, detection should use a combination of conditions:
When these conditions are met, the system can confidently determine that contact with the package has occurred.
This approach is robust and resistant to noise.
The system can also detect empty cycles when:
This indicates the shaft reached the end of travel without encountering a package.
In this the force due to Spring C will be equal to its saturation value due to the high spring gain.
Increasing spring_C_position -> increase distance to reach target approach speed
Decrease spring_C_position -> decrease distance to reach target approach speed
Where the moving mass is a combination of the shaft and any attached components..
Retract speed depends on multiple effects. However, by selecting a sufficiently large return_home_force, other effects (aside from Spring A) can be dominated.
Note:
Initial impact force may also include inertial effects which are not directly measurable.
IrisControls is an accessible interface for testing and tuning purposes, which allows haptic effects to be configured and states to be altered by changing the Constant Force effect value.
All motor functionality is also available through reading and writing to the ORCA motor’s Modbus registers. Configuration can be done and saved to the motor or done at the start of a program.
Then during runtime the following registers should be monitored:
*Note these are all double wide registers and must be combined to a signed 32 bit integer
To control the state change, write to:
The orcaSDK provides a direct function for configuring haptic effects and state control. An example program file is available.