The warning and monitoring devices of electric forklifts are a crucial part of ensuring operational safety. Through "audio-visual reminders" and "environment/state perception", they proactively avoid collision risks, provide early warnings for abnormal working conditions, and cover the safety protection of operators, nearby personnel, and the equipment itself. Specifically, they can be divided into three major categories: audio-visual warning systems, vehicle state monitoring devices, and surrounding environment perception devices. Their detailed functions and application scenarios are as follows:
I. Audio-Visual Warning Systems: Proactively Convey Risk Signals
These devices use dual "sound" and "light" signals to clearly inform nearby personnel of the forklift’s operational status (such as traveling, turning, or reversing). They prevent collision accidents caused by blind spots or noisy environments, serving as a "communication bridge" between the forklift and its surrounding environment.
Travel and Steering Warning Devices
- Turn Signals + Hazard Warning Lights: When the forklift turns or changes lanes, the turn signal of the corresponding direction (yellow flashing light) is activated to remind personnel/equipment behind or on the side to avoid it. If the forklift breaks down (e.g., sudden shutdown, hydraulic failure) and is parked in key locations such as passages or intersections, turning on the hazard warning lights (double flashing) can clearly mark the position of the faulty vehicle and prevent rear-end collisions by other equipment.
- Travel Warning Lights: Mostly high-brightness yellow stroboscopic lights installed on the top of the forklift, they flash continuously during operation. In scenarios with complex visibility (such as warehouse racking areas and personnel-dense workshop areas), these lights significantly improve the forklift’s "recognizability", allowing personnel at a distance to detect the forklift’s movement in advance.
Reverse-Specific Warning Devices
- Reverse Buzzers: Mandatory standard equipment that is automatically activated when reversing, emitting a high-frequency "beep-beep" warning sound (national standards require a volume of ≥85dB). Even in noisy workshop environments with roaring machinery, it ensures that nearby personnel can hear the warning clearly. Some high-end models allow volume adjustment to avoid noise interference in quiet areas.
- Reverse Lights: Activated synchronously with the reverse buzzer, they emit bright white light to illuminate the blind spots behind the forklift (such as ground debris and low obstacles). This not only helps the operator observe the reversing path but also allows personnel behind to intuitively determine that the forklift is in reverse mode through the light.
II. Vehicle State Monitoring Devices: Real-Time Early Warnings for Abnormalities
These devices focus on the forklift’s "own operational state". They collect key data (such as load, height, and battery level) in real time through sensors and feed it back to the operator in a visualized or early-warning form. This prevents equipment damage or cargo falling caused by non-compliant working conditions such as overloading and excessive lifting.
Core Working Condition Monitoring and Display
- Load Monitoring: A weight sensor installed under the fork carriage detects the cargo weight in real time, and the data is synchronously displayed on the cockpit instrument panel. The operator can intuitively judge whether the weight exceeds the forklift’s "rated lifting capacity" (e.g., 1.5 tons, 3 tons). If overloaded, the instrument panel will immediately turn on a red warning light accompanied by a beeping prompt, and at the same time cut off the power supply of the lifting motor to forcefully prohibit further lifting.
- Lifting Height and Mast Tilt Angle Monitoring: Through travel sensors and angle sensors, the fork lifting height (accurate to centimeters) and mast forward/backward tilt angle are collected in real time, with the data dynamically displayed on the instrument panel. When the height approaches the "maximum safe lifting height" (e.g., 3 meters, 5 meters, depending on the model) or the tilt angle is too large (excessive forward tilt may cause cargo to slide off, while excessive backward tilt affects driving stability), an audio-visual warning is triggered to remind the operator to adjust.
- Battery Level and Fault Monitoring: The instrument panel displays the remaining battery level in real time (e.g., percentage, endurance time) to prevent the forklift from shutting down midway due to insufficient power. It also has a built-in fault diagnosis system: if abnormalities occur in the motor, hydraulic pump, or control system (e.g., motor overload, insufficient hydraulic oil), a fault code (such as "E01 Motor Fault") will pop up and an alarm will sound, facilitating the operator to stop the machine for inspection in a timely manner.
Load Stability Warning
To address risks that may cause forklift rollover (such as "cargo center of gravity shift" and "excessive lifting height"), some models are equipped with this function. It analyzes load stability through multi-dimensional sensors (weight, height, tilt angle). If it detects that the forklift’s center of gravity is unbalanced due to one-sided heavy cargo or excessively high lifting height, it will issue a strong warning of "high-frequency beeping + red light flashing", and may even slightly limit the forklift’s traveling speed to forcefully reduce the rollover risk.
III. Surrounding Environment Perception Devices: Compensating for Blind Spots
These devices belong to "advanced safety configurations". Using technologies such as cameras and sensors, they proactively detect obstacles (personnel, racks, other equipment) around the forklift. They specifically target the forklift’s "visual blind spots" (such as the rear of counterbalanced forklifts and the mast-blocked area of reach trucks), further reducing collision risks.
Reverse Cameras and Displays
A camera is installed at the rear of the forklift, and a high-definition display is equipped in the cockpit. During reversing, the real-time image of the rear is displayed (some support night vision to adapt to dim warehouse environments). The operator can clearly see whether there are obstacles such as personnel, pallets, or columns behind without frequently looking back, solving collision problems caused by "reverse blind spots".
Laser/Radar Collision Avoidance Sensors
Mostly installed at the front, rear, or sides of the forklift, they detect the distance to obstacles ahead through laser or radar. Two distances can be set: "early warning distance" (e.g., 1.5 meters) and "emergency braking distance" (e.g., 0.8 meters):
- When the distance is less than the early warning distance, the device issues an audio-visual alarm to remind the operator to slow down;
- If the operator fails to respond in time and the distance further decreases to the emergency braking distance, the sensor will directly send a signal to the control system to force the forklift to slow down or stop (some models only limit the drive motor without affecting steering, ensuring operational flexibility).
These sensors are particularly suitable for "mixed personnel and cargo flow" scenarios such as narrow warehouse passages and high racking areas, effectively preventing collisions caused by the operator’s inattention.
Personnel Proximity Warning System (PDS)
This is a more precise "anti-personnel collision" device. It uses microwave radar or infrared sensors to specifically detect "personnel" within a range of 1-3 meters around the forklift (distinguishing them from fixed obstacles such as racks and pallets). When a person enters the warning area, not only does the forklift issue an audio-visual alarm, but some systems can also link with smart bracelets worn by personnel (if equipped by the enterprise), allowing the personnel to receive vibration/sound reminders simultaneously. This forms a "two-way warning" and further reduces the risk of personnel being hit.
Key Notes
Regular maintenance of warning and monitoring devices is required to ensure their effectiveness:
- Audio-visual devices (such as buzzers and warning lights) should be inspected weekly: Test whether the buzzer volume meets standards and whether the lights are bright, to avoid failure caused by loose wires or blocked horns;
- Sensor-based devices (such as weight sensors and collision avoidance radars) should be calibrated monthly: For example, load sensors need to be calibrated with standard weights to prevent misjudgment caused by data drift;
- Cameras and displays should be cleaned regularly: Remove dust from camera lenses and stains from screens to avoid blurred images affecting observation.
