As robotics technology continues to improve and develop, more and more companies are purchasing and using robots. How can one determine which type of robot to choose? How can we avoid common pitfalls we may not be aware of, or even robots that have already achieved success in application but are not suitable for our needs? Robot investments typically range from tens of thousands to millions of dollars, making the right choice from the outset and avoiding common mistakes is crucial, as errors can lead to unnecessary expenses or task delays. To help engineers and designers avoid the most serious mistakes, this article lists ten common misconceptions to avoid in robot applications.
Myth 1: Underestimating effective load and inertia
The number one misconception among robot users is underestimating payload and inertial requirements. This is often due to failing to include the weight of the tool attached to the end effector when calculating the load. A second common cause is underestimating or completely ignoring the inertial forces generated by eccentric loads. Inertial forces can overload robot axes. Overloading of rotary axes is common in SCARA robots. Failure to correct this problem can damage the robot . Reducing the load or speed parameters can compensate for this. However, reducing the speed will increase unnecessary cycle time—a significant investment consideration when purchasing robots. This is why load-related factors are crucial from the outset.
Yu Renpoli (robotics industry practitioner): The effective load is very important. Generally, the information given in the robot's technical parameters has detailed explanations. The rated load is only effective at the rated speed. One of the important conditions for reaching the maximum load is to reduce the robot's operating speed. In addition, excessive load may also damage the robot's accuracy.
Myth 2: Trying to make robots do too many things
Sometimes, a robot's capabilities and flexibility lead designers to assign it too much work, resulting in overly complex robot cells. This makes it difficult to determine the correct cycle time, introduces additional difficulties to the solution, or even creates significant challenges due to processor speed limitations. Moreover, such errors are often amplified when production stalls occur. Unplanned downtime in production can lead to substantial losses.
Another scenario is when the use of robots and work cells exceeds the capabilities required by the original design. When the added work is added after simulation, disappointing results are easily encountered. Especially if no new simulations are performed before the implementation plan, the specified cycle time may not be met. Therefore, to ensure that a robot's cycle time is within the specified time, actions exceeding the robot's capabilities must be handled with extreme care.
Yu Renpoli: Before using a robot, it is essential to conduct simulations to determine the robot's travel load and cycle time according to the design requirements. If a new application of the robot is to be added, it should be verified before proceeding.
Myth 3: Underestimating the importance of cable management
As simple as it seems, and perhaps too simple, cable management often becomes overloaded. However, optimizing the cable paths to tools or peripherals mounted at the end effector of the robotic arm is crucial for the robot's movement. A lack of anticipation of potential problems can cause the robot to perform unnecessary movements to avoid cable tangling and stress. Furthermore, failing to use dynamic cabling or reduce cable stress can lead to wire damage and downtime.
Yu Renpoli: Currently used robot end-effectors are generally pneumatically or electrically driven, inevitably involving corresponding air pipes or cables. Most industrial robots have external pneumatic and electrical circuits, requiring considerable care during robot motion control. Some industrial robots have internal pneumatic and electrical circuits, which is much more convenient; in this case, only cable management during the relative movement of the arm and end-effector needs to be considered.
Myth 4: Issues to consider before selecting a robot system
By considering each application, once the system is installed, you can determine which applications you need and avoid significant cost overruns due to potential errors. Factors to consider include:
Load – Consider the effective load, direction, and torque;
Orientation – Consider the moving plane, potential obstacles and lubrication issues in the moving plane, and various effects during maintenance;
Speed – This takes into account speed, acceleration, deceleration, and the inertia they produce.
Travel (movement) - Consider the distance of movement, correction, lubrication intervals, and sudden movement of the ball screws;
Environment – Consider ambient temperature, cleanliness, and the presence of corrosive agents;
Duty Cycle – Considers the proportion of time a component is in operation and the thermal effects on the components.
Yu Renpoli: Besides these, the robot's working stroke is also a crucial factor to consider. When determining the stroke, we cannot simply rely on the robot's technical parameters to determine if it meets the application requirements. We must actually consider whether the robot's motion trajectory can achieve the required stroke after the end effector is installed. This is one of the key reasons for conducting simulations. Regarding the environment, different environments require specially customized industrial robots. For example, the painting industry requires explosion-proof industrial robots, which differ from standard robots. There are also cleanroom applications, etc. The robot's reliability, failure rate, and power consumption are all essential considerations when selecting one.
Myth 5: Misunderstandings about accuracy and repeatability
A precise machine is repeatable, but a repeatable machine is not necessarily precise. Repeatability refers to a robot's ability to precisely move between predetermined positions along a defined work path. Precision, on the other hand, refers to the robot's ability to accurately move to a calculated point along a work path. In material handling operations, robots move to predetermined positions through calculation, utilizing the robot's precision capabilities. Precision is directly related to mechanical durability and the precision of the robot arm.
Yu Renpoli: Precision is closely related to the mechanical accuracy of the robotic arm. Higher precision ensures high-speed accuracy, and the robot reducer is a crucial structure for guaranteeing robot precision. Most industrial robots use standard RV-type reducers. However, for applications requiring precision manufacturing, one could consider using industrial robots from Staubliunimation, the pioneer of robotics.
Myth 6: Choosing a robot system depends solely on the quality of its control system.
Most robot manufacturers likely prioritize the robot's controller over its mechanical performance. However, once a robot is configured, uptime depends primarily on the durability of the mechanics. Loss of productivity is more likely due to poor mechanical performance than inadequate controllers and electronics. Typically, the selection of a robot system is based on the user's expertise in the controller and software. If the robot also possesses excellent mechanical performance, this is a significant competitive advantage. Conversely, if the robot requires constant maintenance after installation, the time-saving advantage of expert control will quickly diminish.
Yu Renpoli: The mechanical part is the key to ensuring the performance of an industrial robot. Precision, speed, and durability are all greatly related to the mechanical part. The structure of a robot is relatively simple, generally consisting of a motor and a reducer. If the robot you choose frequently requires maintenance of the reducer or other mechanical structures, it will be very troublesome.
Myth 7: Lack of proper robotics knowledge
Robot manufacturers and system integrators typically design a robot unit for a single application, but failures can occur if users lack proper robotics knowledge. The lifespan of any production equipment is closely tied to how users use and maintain it. It's not uncommon for first-time robot users to refuse training. A crucial condition for ensuring a robot functions properly is a thorough understanding of its capabilities and its optimal use within the work area.
Yu Renpoli: Industrial robots are very specialized pieces of equipment, and their operational complexity is no less than that of a CNC machine tool. Similarly, those who use robots must be familiar with basic industrial robot safety operating procedures; otherwise, it is extremely unsafe for both the equipment and the operators. Robot operators must receive comprehensive safety operation training from the system manufacturer before being allowed to operate the robot.
Myth 8: Ignoring the relevant equipment for robot applications
Teach pendants, communication cables, and some specialized software are usually essential, but they are easily overlooked during the initial order. These can lead to delays and even exceed the budget. When choosing the right robot, one must first consider their overall needs and ensure the equipment meets all requirements. A common situation is that customers sometimes omit key components from the robot in an attempt to save money.
Yu Renpoli: At the beginning of a project, it is essential to understand the necessary equipment, software, and other components. During the procurement process, the products ordered should always be considered in light of the project's application.
Myth 9: Overestimating or underestimating the capabilities of the robot control system
Underestimating the capabilities of a robot control system will result in redundant investment and unnecessary waste. Dual backups for safety circuits are very common. Conversely, overestimating the capabilities of the control system will lead to additional equipment costs, rework, and downtime expenses. Attempting to control too many I/O ports and adding servo systems is a common misconception.
Yu Renpoli: Security control is a very important issue. While considering security, we should also try to optimize the security logic signals of the application. Repetition in the program is unnecessary.
Myth 10: The use of robotics technology has not been considered at all.
Limited investment scale, a lack of understanding of robotics, and past failed attempts at adopting robots are reasons why many people shy away from the technology. However, to improve productivity and ultimately win in market competition, it is crucial to overcome these misconceptions. While robotics cannot increase productivity alone, it can help improve overall production efficiency in many cases . Market response time, increased production efficiency, ease of operation, flexibility, reusability, reliability, precision, controllability, and long-term usability are all powerful reasons for adopting robotics.
Yu Renpoli: Applying robots is a long-term investment. It facilitates management, ensures product yield, improves productivity, and a fully automated factory naturally provides customers with a stable support.
