I. Application of Intelligent Sensors in Robotics
It is the central processing unit that functions like the brain. This computer has a direct connection with the person operating it. Most importantly, this computer can perform operations programmed according to usage. In traditional robots, there are many types of sensors, but with the advent of intelligent robots, sensors also need to possess intelligent functions to meet the growing market demands. Today's robots have the same physical and sensory functions as humans, possess a certain degree of intelligence, have flexible motion programs, and can work independently of human control. All of this is inseparable from the contribution of intelligent sensors, which are crucial helpers for robots to perceive the external world.
Inside a robot, sensors can be categorized into internal and external sensors based on the object they detect. Internal sensors primarily detect the state of various internal systems, such as joint position, speed, acceleration temperature, motor speed, motor load, and battery voltage, sending this information to the robot's controller as feedback to form a closed-loop control system. External sensors acquire information about the robot's working object and external environment. They serve as the information channel for the robot's interaction with its surroundings. These sensors perform vision, proximity, touch, force, and other sensor functions, such as distance measurement, sound, and light sensing.
II. Precautions for using smart sensors
A good sensor design is the result of experience and technology. Generally, it's understood that a sensor uses circuitry to convert physical quantities into a description of those quantities, which can be expressed in a more intuitive way. For example, it might convert this into higher voltage and current signals that depend only on the measured physical quantity, and then display the result. Therefore, several points need to be considered:
First, the measured physical quantity is usually very small, and the inherent conversion noise is typically used as the physical conversion element of the sensor. For example, if the signal strength amplified by 1x by the sensor is 0.1~1μV, the background noise signal at this level is also about the same, and may even be obscured. How to extract as much useful signal as possible and reduce noise is the primary problem to be solved in sensor design.
Secondly, sensor circuitry must be simple and refined. Imagine an amplifier circuit with three stages of amplification and two stages of active filters; it amplifies the signal but also the noise. If the noise doesn't significantly deviate from the useful signal's spectrum, both are amplified simultaneously, regardless of the filter's effectiveness. The signal-to-noise ratio is not improved. Therefore, sensor circuitry must be refined and simple. If a resistor or capacitor can be saved, it must be removed. This is a problem that many engineers designing sensors often overlook. It's known that sensor circuits are plagued by noise problems, and as the circuitry is modified, it becomes increasingly complex, turning into a strange loop.
Thirdly, there's the issue of power consumption. Sensors are typically located at the front end of subsequent circuitry, potentially requiring longer lead connections. When sensor power consumption is high, these lead connections introduce unwanted noise and power supply noise, making subsequent circuit design increasingly difficult. Reducing power consumption within a sufficiently small footprint is a significant challenge.
Fourth point: Component and power supply circuit selection. Sufficient components are essential. As long as the component specifications are within the required range, the rest is a matter of circuit design. Power supply is a crucial issue in sensor circuit design. Don't pursue unattainable power supply specifications; instead, choose op-amps with better common-mode rejection ratios and use the most common switching power supplies paired with differential amplifier circuits. This equipment should meet your requirements. Power supply decoupling must be reliably designed and follow the equipment manual's requirements, not less.
