Pulse Frequency
Last updated
Motion4Sim Shop
Last updated
The speed settings define how fast the calculated pulses are sent to the servo drive, which in turn dictates how quickly the actuator moves. These settings are crucial for ensuring that the movement is safe, efficient, and accurate. Different types of movements—such as homing, transition, and online—require different speed settings for optimal performance.
Purpose: The homing speed determines how fast the actuator moves during the homing process, where it searches for a reference position or limit.
Recommended Value: The homing speed should be slow to prevent potential damage due to high torque forces. High torque can be generated during homing, especially when the actuator encounters resistance or physical limits, so the slower speed minimizes the risk of damage.
Key Point: Homing speed is particularly critical because the actuator could exert significant force as it approaches its hard stops or sensors, so it's important to ensure the homing speed does not induce excessive strain on the system.
Adjustment: While the default homing speed is typically optimized for safety, it can be adjusted if necessary to suit specific hardware or system requirements. However, it is always recommended to keep it within safe limits.
Purpose: The transition speed refers to the speed at which the actuator moves when transitioning from the standby position to the active motion (or park position). This setting controls how quickly the actuator reaches the desired position after starting motion, which is crucial for comfort and operational smoothness.
Recommended Value: Transition speed should be set to moderate to balance efficiency with comfort, ensuring that the actuator moves at a comfortable speed to reach the standby or park position. A higher transition speed might make the movement feel abrupt or uncomfortable, while a slower speed might result in unnecessary delays.
Key Point: Transitioning should be smooth and not too fast. Setting the right transition speed ensures that the actuator can move between states efficiently while maintaining a pleasant and safe operation.
Purpose: The online speed refers to the speed at which the actuator operates while actively engaged in motion, generally during normal operations when the system is live and moving according to user input.
Recommended Value: Online speed should always be set to full speed, as the primary goal is to reach the desired position as quickly as possible. The system should minimize delays to maintain high performance and responsiveness.
Key Point: Online speed is optimized for fast, real-time movement. This setting allows the actuator to quickly move to any required position in response to user commands or real-time data, ensuring maximum efficiency during operation.
Default Values: It is strongly recommended to use the standard values for the speed settings, as these have been optimized for most common applications and ensure the best overall system performance and safety.
Homing speed: Slow (adjustable if needed).
Transition speed: Moderate (to ensure comfort and efficiency).
Online speed: Full speed (to reach positions quickly).
The speed settings also affect the pulse rate, which is crucial for controlling the servo motor. Here’s how pulse speed and motor speed are related:
Normal Pulsing: For regular pulsing, the “Speed for Motion” should not exceed the factory value of around 250-260 kHz.
HW Pulsing with PCB Version >1.09: If using hardware pulsing with PCB version >1.09, the settings can be increased to a maximum of 550-590 kHz. However, higher speeds are possible, but the AASD servo will not accept speeds over 600 kHz. Make sure not to exceed this limit to avoid damage.
Pulse Calculation: The speed of the servo motor is also dependent on the pulse count and the rate at which the pulses are sent to the motor. For example:
For a 10,000 ppr encoder and a motor running at 3000 rpm:
PN98 = 1 → pulse frequency >500 kHz.
PN98 = 2 → pulse frequency >250 kHz.
The PN98 setting is a critical factor when setting the pulse speed:
Consistency: The PN98 setting must be the same in both the controller and the servo driver. If the PN98 setting is higher in the driver than in the controller, there is a risk that the actuator can be damaged due to mismatched pulse counts or incorrect speed settings.
Pulse Modes: This is particularly important when using any pulse mode, so always verify that the PN98 values are properly matched.
Homing Speed: Slow to prevent damage and high torque (adjustable, but recommended to stay low).
Transition Speed: Moderate to move smoothly and efficiently between positions.
Online Speed: Full speed to quickly reach the target position.
Pulse Speed Considerations: The pulse rate affects the motor speed and should be kept within factory defaults or adjusted for hardware pulsing based on the PCB version and servo specifications. Never exceed 600 kHz for the AASD servo.
PN98 Consistency: Ensure that the PN98 setting is identical in both the controller and servo driver to avoid actuator damage.
By following these speed settings and ensuring proper pulse calculations, you can ensure that the actuator operates efficiently, safely, and with optimal performance throughout its range of motion.
