Robots explicitly designed for industrial applications can be characterized according to their operational modes, control systems, mounted tools or interactive mechanisms, and arm geometry. These machines are used for a wide range of manufacturing purposes and play a significant role in industrial system automation. Generally, industrial robots are programmed with either limited or unlimited sequence control, which determines the motion paths taken by the robotic mechanism (such as a tool or a gripper) that interacts with external objects.
Automatic controls can also be servo-based, relying on a closed-loop to provide feedback and enable complete sequence control, or non-serviced, with an open-loop command that doesn’t offer input and relies on limited sequence motions.
An industrial robotic system can handle a broader range of duties than standard automatic machinery, even if the machinery can be equipped with multiple tooling configurations. But although they can be used as multifunctional devices, most industrial robots are designed to specialize in a specific task, such as assembling, loading, painting, or welding. Many robots can perform in applications similar to their field of specialization. Still, operational effectiveness within a given project usually depends on the unit’s size, dimensions, weight, range, speed, repeatability of motion, load capacity, and operating cost.
Powering a Robotic System
Electric motors, hydraulic drives, and pneumatic actuators are the most common mechanisms for industrial power robots. Electric motors feature highly efficient power sourcing and have relatively simple design characteristics, making them one of the more popular options in terms of cost-to-performance ratings. Hydraulic drives tend to be more powerful, enabling robots to have a load capacity over 500 pounds and can work effectively with volatile gases or hazardous substances that present the risk of explosion or fire for electric motors. However, hydraulic drives are more prone to maintenance issues and carry the risk of oil leakage, creating a fire hazard in enclosed spaces. Hydraulic robot systems are also less suited for indoor work in controlled environments close to personnel. Pneumatic actuators are commonly used for powering the mechanisms that interact with external objects, such as the grippers mounted on the end of electric-drive robot arms. A pair of pneumatic actuators working in unison to power a single gripper can enable it to move along multiple axes.
Axis of Motion
Range of motion is an essential determinant of a robotic system’s capabilities. It is usually measured by “degrees of freedom” (DOF), which refers to the number of axes a robot arm can traverse. A standard limited sequence robot can usually move along two or three axes, while its manipulator arm can perform a shoulder swivel, an arm sweep, or an elbow extension. By contrast, an unlimited sequence machine can execute more sophisticated motions along with a more significant number of axes, including pitch, yaw, and roll. A typical heavy-duty robot with complex motion capabilities, such as the one described by RobotWorx, may have as many as six main axes, with each axial motion powered by an electric motor.
A robotic system console typically incorporates a digital computer featuring the operating system and application software needed for running automated tasks. A system operator can program or control automatic movements through a push-button array on the console, enabling some degree of manual control over programmed sequences. During system setup, careful adjustments are made to the programming to ensure the robot does not collide with any surrounding objects while operating.
Industrial robots can also be equipped with handheld control boxes that connect to the computerized control console through cables. These boxes often feature their push-button arrays and graphical display interfaces to improve use. In addition, a qualified operator can sometimes use a handheld control box to train a robotic unit by leading it manually through an assigned task. As the robot completes each movement along an axis, it stores the motion sequence and repeats the routine upon command.
Although larger robotic systems tend to be floor-standing, some variants are designed to be mounted vertically, upside down, or at an angle to improve accessibility within a workspace. These mounting methods provide advantages for specific applications. For example, a vertically-mounted unit can be attached to a structural frame with a rail, allowing it to move a predetermined distance when performing a long weld or painting a large object. Some robots can also be placed in a fixed position on a wall or mounted to enable angular movement.
Robotics System Integration
There are three general issues to creating an effective integrated robotic system: complexity, price, and performance. The ultimate goal is to create a design with optimum performance for the lowest price without an overly complicated solution. In other words, the system should make ample use of modern technology to simplify the system as much as possible, but without compromising performance or price.
Achieving a balance between complexity, price, and performance often involves choosing generalized and specific components. Generalized components can reduce the overall work involved in the production and come with the added benefit of being reusable. If working with generalized components manufactured by the same company, the benefits increase because compatibility between machines is not an issue. Specialized components can tighten the system even more but may require a more significant upfront investment to gain more excellent cost benefits in the long run.
In addition to component selection, there are other methods to maximize the overall performance of an automated system. Bringing together an array of essential robotic components and joining them together to achieve a higher function is the core of creating a computerized system. Still, much of integration hinges on the complexity of the task about the performance of the machinery. To limit a system’s overall level of sophistication, joining only the necessary components for a given job creates an advanced system from essential parts and minimizes unnecessary costs.
There are numerous kinds of software that can aid in creating an integrated system, so evaluating available programs is an essential step in the planning process. However, software choices will vary with hardware components, so carefully examining the designed integrated system and members will help with this decision.