Known as articulated robots, robotic arms include numerous segments supported by joints for rotational or linear motion. Electric motor-powered joints provide a kinematic chain with an end effector for complex motions. More joints and degrees of freedom improve arm flexibility and accuracy. Remember, artificial hand designers believe the human hand has 27 degrees of freedom. A human arm has 7 degrees of freedom, which gives the arm and hand 34 degrees.
On the other hand, industrial robots cannot reproduce all the nuanced human arm and hand movements. However, industrial robot arms with 6 degrees of freedom can do practically any job. Robotic arms' precision and reproducibility suit welding, painting, picking, and placing in manufacturing. Knowing the types of robotic arms helps decide application suitability.
Types of Robotic Arms
1. Articulated Robotic Arms
Articulated robotic arms include shoulder, elbow, and wrist joints for flexibility and agility. Six-axis robots use six rotating joints to replicate human arm movements. Ideal for welding, painting, assembling, and loading/unloading, its construction enables them to do complex operations precisely. In electronics and automotive production, articulated arms are perfect for gently moving and adapting minuscule components. Yet, they are expensive and need complex controls. Although modern models have simpler frameworks, their intricacy might make programming difficult. Despite these shortcomings, their adaptability renders them essential in industrial applications.
2. Cartesian Robotic Arms
Cartesian robotic arms are precise and fast along the X, Y, and Z axes. These simple robots have three prismatic joints for straight-line movement. Therefore, they flourish in high-speed assembly and pick-and-place activities in electronic and automotive assembly lines. Durable and low-maintenance Cartesian robots suit precise placement jobs, including inserting computer chips on circuit boards or sorting items in packing. They are confined to linear movement, which limits their adaptability. However, their efficiency in repeated, precise operations is useful in manufacturing.
3. Collaborative Robotic Arms (Cobots)
One of the types of robotic arms, cobots include sensors that detect contact forces to avoid injury during human interaction. Lightweight and flexible, they outfit CNC machine tending, assembly, and packing. Cobots' user-friendly interfaces make programming and workflow integration easy. Manufacturers pursuing cheap automation without safety restrictions may use them. Nevertheless, cobots are slower and weaker than standard robots. Despite these limitations, they improve productivity and safety in regular production contexts where human-robot cooperation is key.
4. SCARA Robotic Arms
SCARA (Selective Compliance Assembly Robot Arm) robots introduce two parallel rotary joints for speed and accuracy in a plane. Their design suits assembly, packing, palletizing, and material transfer. Due to their agility and precision, SCARA robots outperform in horizontal movement jobs. Automotive and electronics manufacturing lines employ them for better productivity. They lack articulated arms and can only move in a cylindrical work environment. However, their precision and high-speed applications are appreciated in many industrial contexts.
5. Parallel/Delta Robotic Arms
Among the types of robotic arms, Parallel or Delta robotic arms have three arms attached to a base for fast pick-and-place and assembly. These robots ' fast acceleration and accuracy benefit food processing, medicines, and electronics production. Delta robots perform at handling small, lightweight components quickly in semiconductor fabrication. Their limited mobility limits their usage in applications requiring a broad range of motion. For scrupulous synchronization, their detailed architecture demands expert programming. Nonetheless, their exceptional speed and efficiency in high-volume operations are important in fast-paced manufacturing lines.
6. Cylindrical Robotic Arms
The base of cylindrical robotic arms has one rotating joint and two linear joints for a cylindrical work envelope. Their stiffness and precision suit grinding, assembly, and spot welding. Cylindrical robots handle pipes and cables well. Their small stature is ideal for cramped environments. Their mobility is restricted compared to other robotic arms, which hampers their flexibility. Despite these boundaries, their dependability in some activities is useful in certain industrial applications.
7. Spherical/Polar Robotic Arms
Polar or spherical robotic arms have two rotating joints and one linear joint for a simple control system and great reach. Such robots benefit from their spherical work envelope in injection molding, painting, and arc welding. Although less flexible than articulated arms, polar robots may be cost-effective for specific jobs. They are appropriate for operations needing a wide range of motion thanks to their simplicity and efficiency with massive objects. Yet, their size and limited adaptability might be downsides in complicated or space-constrained applications.
8. Anthropomorphic Robotic Arms
Anthropomorphic robotic arms with autonomous fingers and thumbs attain human-like mobility and responsiveness. The arms are for collaborative duties, including bomb disarming and sensitive assembling. Their construction allows for several motions for versatility. However, their complexity, expense, and need for contemporary control systems are downsides. Given these obstacles, their ability to emulate human dexterity is vital in sensitive handling applications.
When Not to Use Robotic Arms
Because of tech restrictions, robotic arms may not always be the ideal option. First, their exorbitant prices, surpassing $100,000 for a reasonably sized project, might render them unsuitable for small or short-term initiatives with low ROI. Even the most refined types of robotic arms cannot perform convoluted visual inspections or subjective quality control assessments. Robotic arms struggle with things that need fragile tactile adjustments or have non-standardized geometry. In collaborative workplaces with people and robots, tricky sensors and control algorithms help avoid accidents, which might complicate integration. Lastly, not every automation task benefits from robotic arms. Choosing the correct automation takes into consideration these concerns.
Choosing the Right Type of Robotic Arm
So, optimizing automation efficiency, affordability, and accuracy requires choosing the correct robotic arm. You must evaluate agility, speed, load capacity, and precision for your jobs.
