• FlexiMotion PLC Function Block
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Advanced PLC Functions For Electric Axis Motion Control

Cutting-edge Technology Functions for High-Performance Motion Control

FlexiMotion: Precision Linear Axis Control for Electric Motors

  • Compatible with various PLC Platforms
  • Linear Axis Position,Speed and Acceleration Control
  • Emergency Stop
  • Linear Axis Jog Movement
  • Motor Speed Control
  • Synchronization Control

Introducing FlexiMotion – a cutting-edge motion controller designed specifically for linear axes driven by electric motors. Whether you’re managing high-precision tasks or ensuring repeatable accuracy, FlexiMotion is the perfect solution to control your linear axis with unparalleled precision and smoothness.

Why Choose FlexiMotion?

  • Universal PLC Compatibility: Forget about specialized technology CPUs! FlexiMotion runs seamlessly on real-time PLC platforms including Siemens S7, Siemens TIA Portal, Rockwell Studio AIO, Rockwell RSLogix 5000, Rexroth IndraWorks, B&R Automation Studio, and Beckhoff TwinCAT, all while delivering the same high performance across the board.

  • Seamless Integration with Existing PLC Programs: The FlexiMotion PLC function can be easily purchased and directly integrated into your existing PLC programs. This allows for effortless scaling and enhancement of your current automation systems without the need for extensive reprogramming or system overhauls.

  • Simplified Commissioning and Parameterization: With comprehensive input/output documentation and practical examples, FlexiMotion makes commissioning and parameterization incredibly straightforward. This reduces setup time and ensures a smooth transition from installation to operation, empowering your team to get up and running quickly with minimal effort.

  • Advanced Trajectory Generator: At its core, FlexiMotion features a powerful trajectory generator that plans the ideal motion profile using a trapezoidal acceleration profile. This approach delivers smooth and precise positioning with every move.
  • Immediate Stop Functionality: Equipped with a configurable Stop input, FlexiMotion provides a quick and safe halt with a controlled deceleration, protecting your equipment and ensuring operational safety.
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Description

The FlexiMotion function is a powerful PLC function block designed for the precise position control of an linear axis coupled to an electrical motor. This function is essential for applications where high accuracy and repeata bility are required. It receives user-defined setpoints for target position, speed, acceleration, and jerk, and uses these inputs to calculate the optimal speed setpoint for the motor. By doing so, the function ensures that the linear axis reaches its target position with exceptional precision and consistency.

At the core of this function is an trajectory generator that meticulously plans the motion profile needed to achieve the target position. This generator guarantees smooth and accurate positioning, making it ideal for demanding automation tasks.

Additionally, the function includes a Stop input, which allows for an immediate halt of the motor with a config urable deceleration rate, providing a crucial safety feature.

The calculated rotational speed setpoint from the function is sent to a motor frequency drive, which then adjusts the motor speed accordingly. It is important to note that the status and control words required for communicating with the motor frequency drive must be managed by the user outside of this function.

The diagram illustrates how the FlexiMotion function block integrates into the overall control system, highlighting its role in achieving precise and reliable position control of the linear axis.

Compatible with various PLC platforms like Siemens S7, Siemens TIA Portal, Rockwell Studio AIO, Rockwell RSLogix 5000, Rexroth IndraWorks, B&R Automation Studio, and Beckhoff TwinCAT, FlexiMotion provides the same high performance on any platform.

Block Diagram

Inputs Description

The sample time, in second, of the cyclic interrupt task of the plc at which the function is running. A higher sampling frequency allows for more precise control.

Is used to define the upper limit for the CtrlOut output, which represents the rotational speed setpoint for the electric motor.

Is used to define the lower limit of the CtrlOut to a specific value.

The SupImpCtrl input is intended for applications where multiple axes need to be synchronized in position or speed or where the torque of the electric motor must be manipulated by a superimposed controller. This input allows an external controller to manipulate the position or speed of the linear axis or the torque of the motor, enabling precise coordination and adaptive control in complex systems. The schematic of the signal flow, as depicted in the accompanying image, illustrates how the SupImpCtrl input interacts with other components within the control system, ensuring that the external controller’s commands are effectively integrated into the overall motion control process. Figure 1

The Digits input is an integer value that determines the resolution of the decimal places for the calculated movement trajectories. This setting controls the precision of the trajectory calculations, ensuring accurate motion control. A value of 4 is recommended, which provides a good balance between precision and computational efficiency, allowing the function to generate smooth and accurate movement paths.

The input allows users to specify the desired target position for the linear axis. It can be defined in any unit appropriate for the application (e.g., meters, centimeters, millimeters, micrometer). When ExeMov Input recognizes a rising edge, the function generates a trajectory from the current position to the specified target. The internal position controller ensures that the linear axis follows this trajectory accurately. Important: It is essential to understand that any changes of the TgtPos , MaxSpdSetPnt , MaxAccSetPnt and JerkSetPnt during axis movement are internally ignored by the function block. The function block responds to changes only when PosTrj matches TgtPos . The Busy ouput serves as an indicator of the block’s readiness: When the Busy output of the block is logicaly True , it indicates that the axis is in motion and the controller will not respond to new setpoints. Conversely, if it is logically False , the axis is in steady state, allowing the controller to react to new setpoints. See figure 2. Figure 2: Position trajectory, actual position and busy signal during movement.
This input sets the maximum allowable speed of the linear axis during the movement. It is defined in the same unit as the TgtPos input, per second. This parameter ensures that the linear axis moves at a controlled speed while reaching the target position. This sets the top speed for the linear axis during movement. See figure 3. Figure 3: Upper limit of the speed and acceleration trajectory.

This input determines the maximum allowable acceleration of the linear axis during the movement. It is measured in the same unit as TgtPos per second squared. This parameter needs to be customized based on the specific system requirements. . MaxAccSetPnt sets the top acceleration for the linear axis during movement. However, factors like distance to travel, maximum speed MaxSpdSetPnt ,and jerk JerkSetPnt might make it have lower acceleration. See figure 3.

JerkSetPnt controls the abruptness or smoothness of motion by regulating the rate of change of acceleration. It is measured in the same unit as TgtPos per second cubed. Adjusting JerkSetPnt allows users to customize the motion profile according to their desired level of abruptness or smoothness. For example, if the maximum acceleration needs to be achieved within half a second, the JerkSetPnt value should be set to double the maximum acceleration value. Setting a jerk value as a setpoint is important for controlling the smoothness of acceleration and deceleration transitions. By managing the rate at which acceleration changes, users can prevent sudden, harsh movements that could cause mechanical wear or instability in the system. This ensures a smoother and more controlled operation, which is especially beneficial in applications where precision and mechanical longevity are critical. Figure 4: Movements with different jerk setpoints.
ParStop
DecSetPnt
The function block includes a stop feature that allows the motor to be halted immediately. As soon as a rising edge is detected on the Stop input, the function triggers a stop ramp to bring the motor to zero speed. The deceleration during this stop is defined by the DecSetPnt input, which can be configured in units such as [rpm/s], [rad/s²], or as a percentage of the nominal speed per second. After the stop input is activated, normal operation of the function can only resume once the acknowledge, Ack , input is activated. This ensures that the system is properly reset and ready for continued use after an emergency or controlled stop. See figure 5. Figure 5: Stop functionality.

It represents the amplification factor of the P-controller within the position controller. A higher Kp value can enhance control accuracy. However, caution is advised: setting the Kp value excessively high may render the closed-loop system unstable. For optimal results and to maintain system stability, it is recommended to initiate with a modest Kp value and incrementally adjust upwards to achieve the desired precision. See example 2 for optimal adjustment.

Ki stands for the integration factor of the I-controller within the position controller. A Ki value set to zero effectively deactivates the I-controller. While a higher Ki value results in swifter error integration, enhancing overall accuracy, it can also introduce increased oscillations in the closed-loop system. For best performance, it is advisable to commence with a low Ki value and gradually increase it until the desired accuracy level is reached, balancing precision with system stability. See example 2 for optimal adjustment.

GainFwdSpdCtrl is a system parameter that adds a constant value for positive velocities to the control signal, improving trajectory tracking. It reduces the error signal and facilitates smoother following of the desired trajectory. The optimal positive feedforward value depends on the hardware and system dynamics, which can be determined through measurement and analysis, as illustrated in example 2.

GainBwdSpdCtrl is a system parameter that adds a constant value for negative velocities to the control signal, improving trajectory tracking. It reduces the error signal and facilitates smoother following of the desired trajectory. The optimal negative feedforward value depends on the hardware and system dynamics, which can be determined through measurement and analysis, as illustrated in example 2.

This input determines the behavior of the I-Controller. When set to False , the I-Controller remains continuously active. If set to True , the I-Controller operates only in the steady state, deactivating during the linear axis movement. We advise setting this input to True , as allowing the I-Controller to function solely in the steady state often provides superior stability and accuracy for linear axes. This approach typically minimizes, if not eliminates, significant overshoots and, by enabling an increase in the Ki factor, greatly enhances accuracy.

The Window input is used to define a positional tolerance band around the target position TgtPos of the ParMovAbs structure. When the absolute distance of actual position ActPos of the linear axis from the target position is within half of the Window value and remains within this range for at least the specified TuneTime (which is configurable in seconds), the function block will send a speed setpoint of exactly 0.0 to the motor. This functionality is crucial for achieving precise positioning. It ensures that when the axis gets close enough to the target position, the motor is gently brought to a complete stop, preventing overshoot and ensuring the axis remains within the desired positional accuracy. In figure 6 you can differentiate between three states:
  1. Window and Positioning: As the actual position (black line) approaches the target position (red dashed line), the difference between them becomes smaller than half of the Window value (illustrated by the blue dashed lines).
  2. TuneTime Activation: Once the actual position stays within this Window range for a duration of at least TuneTime (e.g. 0.5 seconds, as indicated on the graph), the function block signals the motor to reduce speed to exactly 0.0 (as shown in the CtrlOut graph).
  3. Final Positioning: This results in the motor coming to a smooth and controlled stop.
This feature is essential for applications requiring high positional accuracy, as it prevents oscillations around the target position and ensures a stable final position. Figure 6: Behaviour of the tolerance window and tune time.

The TuneTime input specifies the minimum amount of time that the actual position ActPos must remain within the defined Window around the target position TgtPos  before the function block sends a zero-speed setpoint to the motor. This time parameter is configurable in seconds.

The purpose of the TuneTime input is to ensure that the axis has settled within the acceptable positional tolerance before bringing the motor to a complete stop. By requiring the position to stay within the Window for a specified duration, TuneTime helps to prevent premature stopping due to transient conditions or small oscillations. This results in more stable and precise final positioning, reducing the likelihood of overshoot or drift after the motor has stopped. See figure 6

This input controls the activation or deactivation of the function. When the input signal is turned off False ,the function no longer responds to changes in the setpoints and does not generate any trajectory. The monitoring signal PosTrj reflects the current position, while the other monitoring signals SpdTrj and AccTrj are set to zero.
when the function is deactivated, the CtrlOut is set to zero, indicating that there is no movement caused by the controller, as shown in table 2.

CtrlOut PosTrj SpdTrj AccTrj
Enb = True ccalculated based onthe position controlalgorithm calculated by position trajectory generator calculated by speed trajectory generator calculated by acceleration trajectory generator
Enb = False 0.0 reflects current position ActPos 0.0 0.0
Table 2: Behavior of the output signals depending on the Enb input

The input represents the current measured position of the linear axis. It is used in the error signal calculation of the position controller. It should be provided in the same unit as TgtPos of the ParMovAbs structure.

The ExeMov input is used to initiate a movement. When a rising edge is detected on ExeMov input, the function block starts the movement based on the Setpoints on ParMovAbs . This input effectively serves as the start command for executing the programmed motion. see figures 2 to 5.

The Stop input is a critical safety and control feature that overrides all other modes of operation. when a rising edge is detected on the Stop input, the function immediately sends a zero-speed setpoint to the motor. This command is executed with a configurable deceleration rate, ensuring the motor comes to a controlled andsafestop. Thisinput is essential for emergency stops or situations where an immediate halt of the motor is required, providing a reliable way to quickly bring the system to a stop. See Figure 5

The Ack input is used to reset the function block after a stop command has been executed via the Stop input. Once the motor has been stopped, the function block is locked, preventing any further operations until a rising edge is detected on the Ack input. This input serves as a safety feature, ensuring that the system cannot resume normal operation until the stop event has been acknowledged by the user. It allows the user to verify and confirm that the system is ready to continue, ensuring controlled and safe operation after a stop condition.

Output Description

The CtrlOut output is the main output of the function block, responsible for providing the motor speed set point. This output ensures that the linear axis reaches the desired position or safely stops the motor when Stop input is activated. The unit of this output, whether rpm, rad/s, or a percentage of the motor’s nominal speed.

The CtrlOut signal must be connected to a motor speed controller, such as a frequency drive, which trans lates the setpoint into the actual motor speed. CtrlOut is essential for translating the function block’s control commands into motor speed, making it a crucial link between the control system and the motor drive.

The PosTrj output displays the position set trajectory of the linear axis as it moves toward the target position. When the function block is deactivated (Enb = False ) or during the stop function, this output shows the current position of the linear axis. The unit of PosTrj is the same as that used for TgtPos of the ParMovAbs structure. See figures 2 to 5. This output is intended solely for display purposes and should not be used to control other functions, as its reliability for such purposes is not guaranteed by Halow-Tech. It provides a visual representation of the expected or current position of the axis, aiding in monitoring the system’s operation.

The SpdTrj output displays speed trajectory of the linear axis as it moves toward the target position. It has the same unit as MaxSpdSetPnt of the ParMovAbs structure.

The SpdTrj output is intended solely for display purposes and should not be used to control other functions, as its reliability for such use is not guaranteed by Halow-Tech. It provides a visual representation of the expected speed of linear axis, aiding in the monitoring and analysis of system performance.

The AccTrj output represents the acceleration trajectory of the linear axis as it moves toward the target posi tion. It has the same unit as MaxAccSetPnt of the ParMovAbs structure.

The AccTrj output is intended solely for display purposes and should not be used to control other functions, as its reliability for such use is not guaranteed by Halow-Tech. This output is useful for monitoring and visualizing the acceleration profile of the axis, helping users ensure that the system operates within the desired parameters.

The Busy output indicates whether the internal trajectory generator is currently moving toward a target position. While the trajectory is in progress and the axis is moving to the new target, this output will be True . Once the position trajectory the target position reached, the Busy output switches to False . While Busy is True , the function block does not respond to new setpoints or impulses at the ExeMov input, preventing any interruptions or changes during the ongoing motion. See figure 7 Figure 7: Output signal Busy while movement.
The Done output indicates whether the positioning task has been completed. As long as the function block is sending a non-zero speed setpoint to the motor, this output will be False, meaning the positioning task is still in progress. Once the positioning task is complete, the ”done” output switches to True, indicating that the function block is now sending a speed setpoint of exactly 0.0 to the motor. This output is useful for signaling when the movement is fully completed, allowing the user or the control system to know when it is safe to proceed with the next operation or to issue new commands. It helps ensure that the motor has come to a full stop at the desired position before any further actions are taken. see figure 8. Figure 8: Output signal Done while movement.

The Error output is a Boolean array with 2 elements, each indicating a specific error condition that prevents the function block from executing certain operations. Understanding these elements is crucial for diagnosing issues and ensuring the function block operates correctly. This output is essential for monitoring the status of the function block and ensuring safe operation. By checking these elements, users can quickly identify which parameter is causing an issue, allowing them to correct the problem before attempting to execute new movements. This ensures that the system operates within safe parameters and helps prevent unintended behavior or damage to the system. For an overview, see table 2.  

  • Element1: If True, no new movement can occur. This indicates that one or more of the inputs MaxSpdSetPnt, MaxAccSetPnt or JerkSetPnt of the struct ParMovAbs are zero or negative.
  • Element 2 (Stop Condition Error): If True , no new movement can be issued. This element remains True if the stop function has been activated and will only reset when the function’s main output CtrlOut is zero and the Ack input has been activated.
Firs Element=True Second element=True
Error Invalid parameters ParMovAbs Not Acknowledged after Stop
Table 4: The different error codes of the FlexiMotion function block

Frequently Asked Questions (FAQ)

The function block will not respond to any setpint changes during the movement and will continue to move toward the original target. The function block only reacts to the new setpoints when the Busy output is False .

If you deactivate the function block by setting the Enb input to False while the linear axis is in motion or the motor is running at a non-zero speed, the main output of the block CtrlOut will abruptly drop to zero. This sudden change in motor speed can potentially damage the motor or other mechanical components. Therefore, it’s important to ensure that the motor has come to a stop or the movement is complete before deactivating the block.

Tuning Motor Drive Parameters

In this examples, we’ll walk you through the steps to configure the technology block for accurate positioning of an electric axis. This step is essential before proceeding to the next steps, where you’ll tune the control parameters of the position controller.

The Technology Block calculates the motor’s rotational speed setpoint, which is output through CtrlOut . This output needs to be connected to a Frequency Drive that controls the motor’s speed. To ensure precise positioning, it’s crucial that the motor can accurately follow the rotational speed setpoint provided by CtrlOut . To achieve this, start by operating the Technology Block in Mode 5. In this mode, you’ll send rotational speed setpoints along with predefined acceleration and jerk values to the frequency drive.

The first step, described in this example, is to fine-tune the frequency drive’s control parameters so that the motor can quickly and accurately match the rotational speed setpoint, with minimal overshoot. The motor must also be capable of following these speed setpoints at the maximum allowable acceleration and jerk rates, maintaining precision and stability.

Once you’ve ensured that the motor’s speed control is highly responsive and stable, you can proceed to use the Technology Block in Modes 1, 2, 3 and 4 for precise positioning tasks. This initial setup is key to achieving the accurate positioning required in these modes.

Important Safety Note for Operating in Mode 5: When operating the Technology Block in Mode 5, it’s crucial to pay close attention to the position of the linear axis. In Mode 5, rotational speed setpoints are sent to the motor regardless of the position of the linear axis. This means the motor will follow the speed commands without considering the current position, which can lead to unintended movements of the axis. To avoid any potential issues, it’s recommended to perform this step while the linear axis is not yet coupled to the motor, allowing the motor to spin freely without affecting the axis. This precaution helps prevent any accidental damage to the mechanical components or misalignment of the system. If this step is not carefully managed, the motor could drive the axis unexpectedly, leading to possible mechanical damage or even safety hazards. 

The following is an example of the problems that can arise when setting the frequency Drive. At the end of the example, it is shown how precisely the entire system must react in order to use the controller.

The issue of motor speed control in Figure 9 includes two main problems: (a) Large Lag Error: The actual motor speed (blue line) lags significantly behind the motor speed set trajectory (black line), indicating poor tracking performance. The motor takes too long to reach the desired speed, resulting in a slow response. (b) No Steady-State Accuracy: The actual motor speed never reaches or maintains the target speed (red dashed line). Figure 9
The issue in Figure 10 includes two main problems: (a) Large Lag Error: The actual motor speed (blue line) significantly lags behind the set trajectory (black line) during both the acceleration and deceleration phases, indicating a delayed response in following the desired speed profile. (b) Overshoot and Oscillation: After reaching the target speed, the actual motor speed overshoots the setpoint (red dashed line) and exhibits oscillations, indicating poor damping and instability in the speed control, leading to oscillatory behavior instead of smooth convergence to the target speed. Figure 10
The behavior in Figure 11 is better than in both Figures 10 and 9, but there remains an issue: (a) Large Lag Error, where the actual motor speed (blue line) still lags behind the set trajectory (black line) during acceleration and deceleration phases, indicating that the response is still delayed in following the desired speed profile. Figure 11
The behavior in the Figure 12 is an improvement compared to the previous figures, but there is still a relatively large Lag Error: The actual motor speed (blue line) continues to lag behind the set trajectory (black line), indicating a delayed response in following the desired speed profile. While performance has improved, the motor still struggles to match the speed changes accurately. Figure 12
Optimal set of controller parameters in figure 13: The lag error between set trajectory (black line) and motor actual speed (the blue line) is negligibly small, there is no over shoot and no oscillation. steady- state accuracy is very high. Figure 13

How to Configure FlexiMotion Control Parameters

This guide provides detailed instructions on how to set up and configure the Technology Block FlexiMotion for precise positioning tasks of an electric linear axis. To proceed with the following steps, the motor frequency drive must be configured as described in the previous section. This setup is a prerequisite for successful tuning of the position control parameters.

Important for all examples: The values of control parameters provided in the following sections are solely as examples to illustrate the approach for setting control parameters. Under no circumstances should these values be directly applied to your machine, not even as initial starting points. The control parameters must be explicitly adjusted for each machine individually.

  • Cyclic Interrupt task Setup: Ensure that the Technology Block is called within a cyclic interrupt task in your PLC. The feedback for the actual position must be read at least as frequently as the cycle time of the this cyclic interrupt task.
  • Sampling Time: The task cycle time should be relatively fast, depending on the required accuracy and motor dynamics. A sampling time of 1 to 5 milliseconds is a good starting point.
  • Communication with the Frequency Drive: The Technology Block only calculates the speed setpoint for the frequency drive. Control and status words for communication with the drive must be programmed separately by the user. The speed setpoint calculated at the CtrlOut output should be sent directly to the frequency drive without modification.
  • Consistency in Units: Before configuring the block, decide on the units you will use for the system. These units must remain consistent throughout the configuration. For example, if you choose millimeters for the linear axis, then all related variables should be in millimeters: Actual Position [mm], Target Position [mm], Speed Setpoint [ mm/s ], Acceleration Setpoint [ mm/s 2 ], and Jerk [ mm/s 3 ].
  • Other Unit Options: You can choose other units, such as meters, centimeters, micrometers for the linear axis, or rad/s or percentage of nominal motor speed for the motor. The key is to select a unit system and maintain consistency across all parameters and modes.
  • Sample Time: Enter the PLC’s task cycle time (in seconds) into the SampleTime input.
  • Max and Min Output: Define the maximum and minimum speed the Technology Block can output using MaxOut and MinOut , for example, 1500 rpm maximum and −1500 rpm minimum.
  • Kp Setting: Initially, enter a small value for Kp of the CtrlPar structure.
  • Define Accuracy Window: Set the accuracy window using Window input in the same units chosen for the linear axis (e.g., 0.2mm).
  • Tune Time: Enter a value in seconds for TuneTime (e.g., 0.3s).
  • Other Control Parameters: You can leave other control parameters at zero for now; they will be adjusted later
  • Block Activation: Activate the block by setting Enb to True . Trigger a movement by sending a pulse to the ExeMov ‘ input and observe the linear axis movement.
  • The goal at this stage is to ensure that the actual position and the generated position trajectory (PosTrj output) are parallel. Do not focus on target accuracy at this point. See figure 14.
Figure 14: Example with Kp too small! (Kp = 10, Window = 0.2mm, TuneTime = 0.3s)
  • Incremental Kp Adjustments: Gradually increase the Kp value. After each increment, execute a new movement by defining an appropriate target position and sending a pulse to ExeMov .
  • Objective: Continue this process until the position trajectory (PosTrj ) and the actual position are parallel, indicating proper tuning. see figures 15, 16 and 17.
Figure 15: Kp increased to 20, still small! (Kp = 20, Ki = 0.0, GainFwdSpdCtrl = 0.0, GainBwdSpdCtrl = 0.0, Window = 0.2mm, TuneTime = 0.3s) Figure 16: Kp increased to 50, still small! (Kp = 50, Ki = 0.0, GainFwdSpdCtrl = 0.0, GainBwdSpdCtrl = 0.0,Window=0.2mm, TuneTime = 0.3s)) Figure 17: Kp increased to 200, ready for next step! (Kp = 200, Ki = 0.0, GainFwdSpdCtrl = 0.0, GainBwdSpdCtrl = 0.0,Window = 0.2mm, TuneTime = 0.3s)
  • Execute a Positive Movement: Run a positive movement of the linear axis.
  • Measure Motor Speed: At a point where the actual position and the position trajectory (PosTrj ) are parallel, read the motor speed.
  • Calculate GainFwdSpdCtrl: Divide the motor speed by the set speed value (MaxSpdSetPnt of the structure ParMovAbs ). The result is the value you should enter into GainFwdSpdCtrl of the structure CtrlPar . In the example shown in figure 16. The MaxSpdSetPnt was set to 5 [mm/]s. The motor speed is 520.52rpm(see figure 17).
    The value for GainFwdSpdCtrl is then calculated by: GainFwdSpdCtrl => 520.52/5= 104.1

Figure 18: Adjusted Feedfordward parameters (Kp = 200, Ki = 0.0, GainFwdSpdCtrl = 104.1, GainBwdSpdCtrl = 0.0, Window = 0.2mm, TuneTime = 0.3s)

  • Repeat Step 7: Perform the same process as in Step 7, but with a negative movement of the linear axis.
  • Calculate and Set Gain: Write the resulting value into GainBwdSpdCtrl of the strucutre CtrlPar .
  • Execute a Movement: Run a movement using the Kp = 20 value and the determined feedforward parameters.
  • Analyze the Motion: The movement should resemble the ideal trajectory shown in reference images (e.g., similar to figure 18).
  • Refine GainFwdSpdCtrl : Determine the positive feedforward gain again by observing the highest motor speed during the movement. Divide this by the set speed value (MaxSpdSetPnt ) and update GainFwdSpdCtrl with this value. See figure 18. GainFwdSpdCtrl = 553.88 / 5 = 110.7
  • Refine GainBwdSpdCtrl : Repeat the process with a negative movement to refine GainBwdSpdCtrl .
Figure19: (Kp=200,Ki=0.0,GainFwdSpdCtrl =104.1,GainBwdSpdCtrl =110.7,Window=0.2mm,TuneTime=0.3s).
  • Monitor Signals: Observe the time between when the Busy signal is reset and when the Done signal is set.
  • Increase Ki : Gradually increase the Ki value and minimize the TuneTime to achieve the desired speed and responsiveness.
  • Optimal Configuration: Once the Kp , feedforward parameters, and Ki are tuned, the position controller is optimally set.
  •  You can now move the linear axis with any target positions, speeds, accelerations, and jerks that your mechanics and motor can handle, without needing to adjust the CtrlPar values again.
  • By following these steps, you ensure that your Technology Block is finely tuned for accurate and responsive control, enabling smooth and precise operation.

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