An industrial robot is equipped with a suction cup fixture. In order to complete suction cup handling, the robot needs to set when to suck up and when to place workpieces, which involves a signal issue.
The brain of industrial robots, also known as the control system, achieves real-time monitoring, control, and feedback of robots through a series of different signals.
Signals can be roughly divided into two categories: one is digital signals, which are characterized by being either black or white, represented by two states of 0 and 1, such as light switches (on=1, off=0), computer keyboard keys (press=1, release=0), as in the case of controlling suction cup suction or discharge, with two options. Another type is analog signal. This is a continuously changing signal with infinite possible values, such as a thermometer (25.3 ℃/25.4 ℃...) and a mobile phone volume adjustment (0%~100% arbitrary value), which can be used to adjust the welding voltage in robot applications.
The signal runs through the internal and external control of the robot, forming the communication bridge between the robot's internal control and external devices.
The signal sounds complex, but our ultimate goal is to make the robot move as required. In the programming process of robots, signal processing is a matter of input and output, where the cocoon is peeled and the silk is drawn.
signal output
Signal output refers to the signals sent by industrial robot controllers to external devices, used to indicate the status of the robot or perform specific operations. These signals are usually generated by robot controllers based on program logic and output to external devices through I/O boards.
Just give an example to understand
The logical process of suction cup action transportation:
1. The robot moves to the designated location. (Record points through teaching pendant)
Trigger the suction cup to open. (Robot sends signal output, communication)
Waiting for suction cup confirmation signal.
The suction cup holds onto the material.
The robot moves to the next position. (Record points through teaching pendant)
Trigger the suction cup to close. (Robot sends signal output, disconnected)
Waiting for suction cup confirmation signal.
Robots place materials.
In the programming program of industrial robots, the signal output of robots is further divided into many types. Taking the Borunte robot as an example, for the convenience of users, we classify the signal output into:
Signal output - Y signal (basic output)
The Y signal is the basic signal type that robots output to external devices. It can be set through the action menu on the teaching pendant, and users can choose whether to delay the output. For example, when the robot reaches the feeding point, it can control the suction action of the suction cup tool through the Y signal. The output state (on or off) of the Y signal can be set in the program, and the delay time can be set.
for instance:
The robot moves to the feeding point → outputs Y1 (on) → the suction cup is powered on to adsorb the cardboard box.
After placing on the tray, output Y1 (disconnected) and release the cardboard box when the suction cup is powered off.
Delay setting: During adsorption, a delay of 0.5 seconds can be set (ensure stable adsorption before moving).
Signal output - board output (multi signal synchronous control)
Board output refers to the output of multiple signals by pointers, typically used to simultaneously control multiple external devices. For example, Y fifteen segments and Y sixteen channels can be output simultaneously. The board output can choose between IO board or M-board, where IO board is physical and M-board is virtual. The default ID for board output is 0. If using an expansion board, the corresponding ID needs to be selected.
The stamping production line requires multi station collaboration, and the robot needs to trigger both the stamping machine and the feeding machine simultaneously.
Application: Use board output (IO board) to simultaneously send:
Y15 (on) → Start the stamping machine.
Y16 (Tong) → The feeder pushes new materials.
Expansion board: If there are multiple IO boards on the production line, an ID must be specified to distinguish the control area.
Signal output - intermediate variable
The intermediate variable (M) is a virtual signal used for signal exchange between the main program and subroutines. It does not require binding external devices, but is controlled through program logic. For example, M10 can be output in the main program, while waiting for M10's signal in the subroutine. Intermediate variables are commonly used for conditional jumps and signal detection.
Step by step process control of assembly line
Scenario: The main program controls the assembly process, and the subroutine executes the screw tightening action.
Application: The main program completes part positioning → outputs M10 (pass) → triggers the subroutine to start screwing.
The subroutine detects the M10 signal and executes it. After completion, it resets M10 (disconnected).
Signal output - time output Y (timed on/off)
Time output Y refers to first turning on the Y signal output when the program reaches that line, and then automatically disconnecting it according to the set time. While waiting for disconnection, the program will continue to execute the next action. For example, the Y signal can be set to automatically disconnect after two seconds.
Spray robot control spray valve scenario: The robot sprays a fixed duration of time on the workpiece.
Move to the spraying position → Time output Y2 (continuous for 3 seconds) → Spray valve opens for 3 seconds and then automatically closes.
The program continues to execute: while spraying, the robot has started moving to the next workstation.
Signal output - Interval output Y (periodic action)
Interval output Y refers to outputting the Y signal according to the set action time after the program has run a certain number of times. For example, after running the robot five times, it can output a signal to clean a certain area. The interval output Y can be set to three states: on, off, or continuous output.
Signal output - Interval output M (virtual signal count)
Interval output M is similar to interval output Y, but uses an intermediate variable M. It can also be set to output in three states: on, off, or continuously, and the count can be saved through a counter.
Case: Quality inspection and sorting of defective products
Scenario: Trigger the alarm light after detecting 5 defective products (without directly controlling the hardware).
Application: Set interval output M20 (count=5, output=on) → The main program detects M20 and activates the alarm subroutine.
Counter storage: The current number of defective products can still be remembered even after power failure.
Signal output - EUY (European standard high-precision control)
EUY signal has similar functions to Y signal, but it is a European standard signal mainly used in industries such as injection molding and die-casting. EUY signals can be bound to multiple signals, such as switchable signals and top and bottom signals. EUY signals are typically used in industrial scenarios that require high-precision control.
These signal output types provide rich control methods for programming the BORUNTE robot, allowing users to choose the appropriate signal type according to specific job requirements, thereby achieving more flexible and efficient automation control.
INPUT
Signal input refers to the signal sent from an external device or system to an industrial robot controller, used to notify the current state of the robot or changes in the external environment, and is generally used to wait for instructions.
It allows robots to adjust their behavior based on changes in external conditions, thereby achieving more flexible and automated operations.
Signal input is usually transmitted to the robot by external sensors for waiting for external instructions. For example, when the sensor detects an object, the input signal will be valid, triggering the next step of the program execution. In addition, signal input can also be used to control whether the robot can continue to run, for example, when an external device sends a "can run" signal, the robot will receive the signal and continue executing the program.
In the actual use of the BORUNTE robot, it is necessary to enter from the "waiting interface" of the teaching pendant to find the signal input - X signal.
Users can choose to input signal X and set the type of signal, such as on, off, rising edge, or falling edge. On/off indicates waiting for external signal on/off changes, while rising and falling edges respectively indicate controlling output at the moment of button press or release. For example, rising edge signals are typically used for normally open signals, while falling edge signals are used for normally closed signals.
For example, in a stamping automation production line, robots wait for safety door signals while they perform loading and unloading operations next to the stamping machine. When the operator opens the safety door, the robot must immediately stop moving to prevent injury.
Control logic: The safety door is equipped with a magnetic switch (normally closed type), and the signal is disconnected when the door is opened (triggered by a falling edge).
The robot needs to detect this signal and pause the program until the door closes (signal resumes).
It sounds complicated, but in fact, you can understand it with more operations. To turn textual knowledge into theoretical knowledge, you still need to put it into practice. The input and output of this signal are really basic programming operation instructions. If you have any knowledge about industrial robots that you would like to see, please feel free to communicate with me in the comment section.