Home：NEWS / Parallel Robots Motion Control: Trajectory Planning Essentials
2025-05-11 6274
Parallel robots are special kinematic chains where multiple actuators dictate the position/movement of an end effector. Parallel robots differ from serial robots wherein a chain of motion is dictated through the connection of each respective joint; instead, parallel robots utilize the connectivity of multiple legs or branches that can move simultaneously toward the desired operation of an end effector. Such a configuration can yield several benefits regarding stability, precision, and operation speed. Learn how these high-performance parallel robots motion control are revolutionizing industries like automation, medical robotics, and aerospace.
These cater to current industrial needs, and they have advanced motion control systems that provide precision and quality during part manipulation. The ability to travel such great distances also means that these robots can span great work areas and thus offer flexibility in positioning assembly lines, and of course, flexibility of use for all industrial purposes. Of course, the focus on parallel kinematics primarily relates to kinematics—the study of motion without regard for the forces that created that motion—and parallel robots kinematics steer how the different joints and actuators move and respond to one another. Two kinematic types of importance are:
Forward Kinematics (FK): The calculation of the position/orientation of an end effector given certain joint parameters.
Inverse Kinematics (IK): The calculation of joint parameters that will render an end effector position/orientation.
These kinematic models are essential to effective motion planning and control. The mathematical formulation of how the robot typically moves involves Jacobian matrices.
Whether the parallel robot needs to work faster—for pick and place applications, surgical applications, or even flight simulations—it needs to travel along a pre-established path. Therefore, motion planning and control algorithms include:
This is defined as establishing how fast something moves, in which direction, and what sort of acceleration/deceleration is needed for maximum utility without loss of precision. Restrictions are maximum velocity, acceleration, and working envelope.
Two types of feedback exist as a control for motion planning. First, feedback control occurs when a measurement notes that the robot has done something wrong, and real-time data is used to correct such a problem. Feedforward control exists when the system believes something will go wrong it recognizes a potential problem—and instead of employing real-time data to adjust, accounts for such measurements on the anticipatory side.
These considerations are essential for dealing with uncertainties and disturbances in varying environments. Adaptive control changes control parameter settings based on feedback from system performance, while robust control ensures stability where parameter settings are fixed despite uncertainties about the system.
Parallel robots are overdetermined for certain controls that prevent certain positions. These trouble spots are called singularities, meaning that either the workspace is limited or the manipulator no longer has available degrees of freedom. Avoiding singularities is crucial for controlling the robot's activity (or inaction) and its successful ability to complete a task. Workspace assessment is the process of determining an active range of motion to ensure the end effector can reach every accessible position.
Parallel robots have a similar dependence and usage across multiple fields due to their versatility and precision. The most common applications are:
Parallel robots are heavily utilized in industrial automation as they are the actuators for fast pick and place operations, robotic assembly, and machine tools. The fast increases in speed and precision directly impact assembly line productivity.
The medical industry uses robots to perform surgeries that the human body cannot perform with the precision and accuracy needed. The motion control features associated with these types of robots allow for better precision in surgery, reducing human error and helping patients.
The Stewart platform is seen in many flight simulators as it can offer accurate motion feedback. The precise motion control allows people to see how it feels to be in the air.
Parallel robots assist with creating force feedback devices that allow people to "feel" something virtually. This is critical for gaming, surgery-assisting robotics, and training simulators.
Various performance measures would need to be evaluated to decide whether or not a parallel robot operates effectively. These include:
• Accuracy: The level of deviation from the desired position.
• Precision: The repeatability of the same task with minimal error.
• Repeatability: Reliability in executing the same motion consistently.
• Speed: The velocity at which a robot executes its intended actions.
• Stiffness and Vibration Control: Determine the level of rigidity and stability of a robot during movement, essential for precise tasks.
As the robotics industry advances, there's an increased reliance on control through neural networks and fuzzy logic. These provide a form of AI and machine learning solutions that can enhance parallel robot motion control systems. Furthermore, the use of model predictive control (MPC) has become increasingly common to anticipate movements and optimize the robot's pathways.
The future of parallel robots motion control depends on advancements in control algorithms, sensing, and computation. Potential developments through artificial intelligence and machine learning will enhance precision, adaptability, and autonomy. As Industry 4.0 spreads across the globe, the need for smart and high-performing robots will rise increasingly, keeping this field developing.
Parallel robots are changing the landscape of industry by providing precise motion control with maneuverability and speed. The parallel robots' motion control realm is an exciting place to be. Whether your projects involve everything from industrial to surgical robots, understanding the basics of this next-generation field will put you ahead of the robotics learning curve. Contact Warsonco Robots to learn more about parallel robots and motion control technology.
