There are various types of robot joints. It’s helpful to learn about these different joints so you can better understand the workings of the robots you are using.
If you are looking for more details, kindly visit ARCSEC DRIVE.
Each joint type will affect the range of motion and capabilities of your robot.
The challenge for newer robot users is that there are different ways to categorize robot joints. This can make them confusing.
A basic understanding of the types of joints can really help you get the most from your robots. In this article, we explore the various ways you can look at robot joint types.
Like many people, you might just look at a robot and see it as a single machine. The robot operates as a single unit. However, you can also “zoom in” on the robot and look at its component parts.
All industrial robots are basically just a chain or collections of “joints.” Robot joints are mechanisms that create motion in one or more of the robot’s axes. Together, the robot’s joints create the desired motions of a robot’s limbs.
It’s helpful to know about robot joint types so you can understand which robots will be most suitable for your needs.
There are 3 basic ways you can categorize robot joints:
Each of these offers a useful perspective as to what makes a particular robot joint work. We’ll look at each of them in turn below.
The first way to categorize robot joints is by their actuation type. An actuator refers to any mechanical or electromechanical device that creates motion. The actuator generates a force using a particular type of energy.
Here are the 3 basic types of robot actuators:
An electric actuator converts electrical energy into motion with an electric motor. This creates a torque that moves the robot joint.
Electric actuators are probably the most common actuator type in robotics. They are fast, precise, and very portable. Although they are not as powerful as the other 2 types of actuator, they offer a good cost-to-strength ratio.
A pneumatic actuator creates force through the application of compressed air. As many manufacturing facilities already have pneumatic lines installed, this can be a handy option and is often used for robot tools.
Benefits of pneumatics include its fast speed and simplicity. However, it offers limited power compared to hydraulics and requires a lot more extra hardware (pumps and pipes) compared to electric systems.
A hydraulic actuator uses pressurized liquid to create motion. They offer more strength than the alternatives, which is why hydraulics are often used for heavy-duty applications.
Hydraulic robots are often the strongest with a high range of mobility. However, they are expensive, require high maintenance, and can be very messy if the liquid leaks.
Another way to look at robot joints is to classify them by how they move. This is determined by their kinematic design. Each joint will have one or more degrees of freedom which are arranged differently depending on the joint type.
Here are the 3 most common joint types by kinematic design:
A linear or prismatic joint can move in a translational or sliding movement along a single axis.
It is probably the simplest type of joint to imagine and is the easiest to control. Actuating the joint makes it longer or shorter.
A revolute or rotational joint moves around a point about one degree of freedom. You can think of a revolute joint as being like the elbow joint in your arm — it can bend only in one direction.
Most industrial robots comprise a series of revolute or rotational joints. As a result, there are well-established control strategies for revolute joints.
A spherical joint can move in multiple degrees of freedom around a single point. You can think of a spherical joint as being like the top shoulder joint of your arm — it can move in multiple directions but around the same point.
Spherical joint control can get quite complex. Sometimes, it’s easier to describe the spherical joint as being 3 revolute joints with an axis that intersects at a common point.
Are you interested in learning more about Robot Joint Actuator? Contact us today to secure an expert consultation!
The last way to look at robot joints is often the most useful for industrial robotics. Here, we look at the robot joint by its function or role in an industrial manipulator.
The 3 functions of an industrial manipulator joint are:
The shoulder joint sits at the base of a robotic manipulator.
It is often the biggest joint and determines how much the robot can turn around. It has the most significant effect on the size of the robot’s workspace.
The elbow joint sits in the middle of the robotic manipulator.
It has the most impact on the robot’s lifting strength and sets a large proportion of the robot’s range of motion. If the elbow joint is restricted, the robot’s workspace will also be restricted.
The wrist joint sits at the end of the robotic manipulator.
It has the most effect on the position of the robot’s end effector. Often, wrist joints can spin a full 360 degrees. It is also subjected to more vibrations caused by the environment than other joints.
Now that you know the basics of robot joints, you can understand a little more about how robots are designed.
However, unless you are building your own robots, you probably don’t need to know much more. It’s most useful when you know the type of robot that you will use and how you can apply them to your particular application.
With the right robot programming tool, the software handles most of the complexity.
There is a seemingly endless selection of DC, stepper, and servo motor products on the market, each with their own advantages and drawbacks. Going into the selection process having answered a few key questions will vastly simplify the selection process.
Article from | Rozum Robotics
With their many parts and the need to be able to smoothly rotate all of their axes, jointed arm robots require the perfect actuator to power their specialized movement with the right type and amount of force. Robots with jointed arms are often tasked not only with mundane tasks, but also with performing human-like actions in dangerous or high-stakes environments, so the motor must be perfectly matched to these requirements. There is a seemingly endless selection of DC, stepper, and servo motor products on the market, each with their own advantages and drawbacks. Going into the selection process having answered a few key questions will vastly simplify the selection process.
There are several factors to consider when selecting a motor to power a robot with a robotic joint
1. What type of robotic joints are used? There are five types of robotic joint: linear, orthogonal, rotational, twisting, and revolving. Does your application use the simpler linear and orthogonal joints, the more dynamic rotational, twisting, or revolving joints, or a mixture of both? This will determine the types of motions and the related nuances of their requirements.
2. How much noise is tolerable in the application? If your application will be used in a factory largely away from people, noise may not be an issue. But if it will be used alongside humans for more than a brief amount of time, you may favor a quieter motor.
3. How much precision is required? When a robot is being used to move shelves in a warehouse, not much precision is required, whereas there is no room for error when one is filling prescriptions. Different motors provide precision in different ways, some with distinct disadvantages; it’s important to know which of these may be allowable for your product.
4. How much torque is necessary? Torque can be achieved at various speeds and with varying degrees of constancy. If you need high torque only at a particular speed, you may be able to sacrifice unnecessary torque capability for other motor features.
Now let’s review the three types of electric motors most often used to run applications on a typical jointed arm robot—DC, stepper, and servo—against these considerations.
DC motors come in brushed and brushless varieties. It is commonly thought that brushless DC motors have supplanted brushed ones, but brushed DC motors are still quite popular for some applications. A brushed DC motor is about 75%–80% efficient, achieves high torque at low speeds, and is simple to control, but creates quite a bit of noise due to the brushes used to rotate the machinery. On the other hand, a brushless DC motor is quieter, even more efficient, and can maintain continuous maximum torque, but is more difficult to control and can sometimes require a specialized regulator. Although DC motors usually provide low torque, they can achieve high speeds and are good for washing machines, fans, drills, and other machines that require constant circular motion.
There is always the option of adding a gearbox to the system to create more torque for robotic applications utilizing a robotic joint mechanism. Keep in mind, the motor and gearbox should be designed to work together, so purchasing a motor with an integrated gearhead is a good idea in this case.
Stepper motors can control precise movement, have maximum torque at low speeds, and are easy to control, making them popular in process automation and some other robotics. However, they come with several drawbacks: They are noisy and relatively inefficient, and they run hot since they continuously draw maximum current. Finally, since they have low top speeds, they are known to skip steps at high loads, which can be a critical flaw in some jointed arm applications. Despite these limitations, they have proven effective in medical imaging machines, 3D printers, and security cameras.
Servo motors provide extremely precise movement, thanks to a feedback loop that senses and corrects discrepancies between actual and target speed. They can provide high torque at high speeds, and can even handle dynamic load changes. Additionally, servo motors are lightweight and efficient. Downsides of using servo motors include their possibility for jitter as they respond to feedback and their requirement for sophisticated control logic. Despite these drawbacks, the precision offered by servo motors often make them a good option for a jointed arm robot, the sophisticated movement of which is designed to match that of humans!
Your jointed arm robot may perform sensitive tasks and come with high expectations, so you need a motor that not only powers your system but makes your robot maximally appropriate for the environment in which it operates. When selecting a motor, making sure you know exactly what you’re trying to achieve and ranking your priorities will help you make smart functionality tradeoffs for optimal performance and suitability.
For more information, please visit rv reducer.