Forklift indoor and outdoor state detection speed limiting system based on millimeter wave radar

Abstract

The utility model discloses a kind of forklift indoor and outdoor state detection speed limiting system based on millimeter wave radar, including battery module, electric control module, instrument color screen module, domain control module, DC-DC module and roof detection module, the output end of battery module is connected with the input end of electric control module and the input end of DC-DC module respectively, the output end of electric control module is connected with traction motor and pump motor respectively, the output end of DC-DC module is connected with the input end of instrument color screen module, domain control module and roof detection module respectively, the output end of roof detection module and instrument color screen module is connected with domain control module through CAN bus, the output end of domain control module is connected with battery module and electric control module through CAN bus.The utility model is detected whether forklift is located indoors by roof detection module, and domain control module obtains speed control strategy by combining forklift operating state information operation, which is transmitted to electric control module by CAN bus to control forklift operation, thereby improve the safety of forklift indoor operation.

Description

Technical Field

[0001] This utility model relates to the field of forklift technology, and in particular to a forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar. Background Technology

[0002] Forklifts are widely used in warehousing and logistics, production workshops, freight yards, and loading / unloading docks. A single forklift often needs to frequently travel between indoor warehouses and outdoor areas. Due to narrow aisles, high personnel density, and obstructed visibility by shelving and building structures indoors, forklifts are generally required to operate at lower speeds to ensure safety. However, in open outdoor areas, to improve handling efficiency, it is desirable forklifts to operate at relatively higher speeds. Therefore, the requirements for controlling the maximum speed of forklifts differ significantly under different operating environments.

[0003] In existing technologies, some forklifts uniformly limit the overall vehicle speed by setting a fixed maximum speed parameter in the vehicle controller or by using mechanical throttling or electronic speed limiting. While this approach is simple in structure, it cannot adaptively adjust to indoor and outdoor environments, often resulting in either low efficiency in outdoor conditions or safety hazards related to speeding in indoor conditions. Other solutions achieve differentiated speed control by manually switching between indoor and outdoor modes or selecting different gears or driving modes; however, this relies excessively on the driver's subjective operation, making it prone to missed or incorrect speed adjustments and resulting in poor management reliability.

[0004] To improve automation, some systems attempt to utilize external infrastructure such as RFID tags, geomagnetic markers, QR code signs, UWB base stations, or ground induction coils to deploy identification devices in fixed areas. When a forklift passes through the corresponding area, it triggers speed limits or alarms. While this approach can manage vehicle speed to some extent based on area, it requires large-scale hardware modifications and wiring to the site, resulting in high construction costs and a significant workload for subsequent maintenance. Furthermore, if the work area or logistics flow changes, the infrastructure needs to be relocated or replanned simultaneously, leading to poor flexibility and hindering its widespread application in complex operating environments with multiple vehicle types and working conditions. Utility Model Content

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to propose a forklift indoor / outdoor status detection and speed limiting system based on millimeter-wave radar. The system uses a roof detection module to detect whether the forklift is indoors, and a domain control module combines the forklift's operating status information to calculate a speed control strategy. This strategy is then transmitted to the electronic control module via a CAN bus to control the forklift's operation, thereby improving the safety of forklift operation indoors.

[0006] According to this utility model, a forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar includes a battery module, an electronic control module, an instrument panel module, a domain control module, a DC-DC module, and a roof detection module for detecting whether the roof is indoors. The signal output terminal of the battery module is connected to the signal input terminals of the electronic control module and the DC-DC module, respectively. The signal output terminal of the electronic control module is connected to a traction motor and a pump motor, both controlled by speed encoders, respectively. The signal output terminal of the DC-DC module is connected to the signal input terminals of the instrument panel module, the domain control module, and the roof detection module, respectively. The signal output terminals of the roof detection module and the instrument panel module are both connected to the domain control module via a CAN bus. The signal output terminal of the domain control module is connected to the battery module and the electronic control module via a CAN bus.

[0007] Preferably, the battery module includes a battery body, a first DC-DC chip, and a BMS battery management subsystem. The first positive output of the battery body is connected to the input terminal of the BMS battery management subsystem through the first DC-DC chip. The electronic control module includes an electronic controller, and the KSI port of the electronic controller is connected to the enable control terminal C of the first DC-DC chip.

[0008] Preferably, the DC-DC module includes a second DC-DC chip. The second positive output of the battery body is connected to the B+ port of the power controller and the positive input port of the second DC-DC chip via a switch MR. The third positive output of the battery body is connected to the enable control terminal C of the second DC-DC chip via an emergency power-off switch and a key switch. The B- port of the power controller and the B- port of the second DC-DC chip are both connected to the negative terminal of the battery body.

[0009] Preferably, the roof detection module includes a roof radar and a laser rangefinder, both used for detecting roofs. The positive output terminal of the second DC-DC chip is connected to the positive input terminal of the roof radar and the laser rangefinder, respectively, and the negative output terminals of the roof radar and the laser rangefinder are both connected to the negative input terminal of the second DC-DC chip.

[0010] Preferably, the domain control module includes a domain controller, the positive input terminal of which is connected to the positive output terminal of the second DC-DC chip, and the roof radar and laser rangefinder are both connected to the domain controller via a CAN bus.

[0011] Preferably, the domain controller is further externally connected to a seatbelt switch, a seat switch, a forward / reverse switch, a handbrake, a foot brake switch, an accelerometer switch, a horn, and a steering wheel angle sensor. The positive output terminal of the second DC-DC chip is connected to one end of each of the seatbelt switch, seat switch, forward / reverse switch, handbrake, foot brake switch, accelerometer switch, horn, and steering wheel angle sensor. The other end of each of the seatbelt switch, seat switch, forward / reverse switch, handbrake, foot brake switch, accelerometer switch, horn, and steering wheel angle sensor is connected to the signal input terminal of the domain controller.

[0012] Preferably, the signal output terminal of the domain controller is connected to the negative input terminal of the second DC-DC chip via an indoor speed warning light.

[0013] The beneficial effects of this invention are as follows: By setting up a roof detection module composed of a roof radar and a laser rangefinder, the space above the forklift can be directly detected in real time, accurately determining whether the forklift is currently in an indoor environment. This eliminates the need for additional external infrastructure such as RFID tags, geomagnetic coils, or UWB base stations in warehouses or factories, enabling automatic identification of indoor and outdoor conditions. This significantly reduces site modification and maintenance costs and maintains good adaptability even when the work area or logistics flow is adjusted. Secondly, this invention unifies the multi-source operating status signals from the roof detection module, instrument panel module, seat belt switch, seat switch, forward / reverse switch, handbrake and foot brake switches, accelerometer switch, and steering wheel angle sensor into a domain control module. The domain controller calculates the speed limit strategy based on the indoor and outdoor conditions and the vehicle's operating status, and sends control commands to the electronic control module via the CAN bus. The electronic control module, in conjunction with the speed encoder, implements closed-loop control of torque and vehicle speed for the traction motor and pump motor. This ensures safe low-speed driving indoors while also considering operating efficiency under outdoor conditions, significantly improving the accuracy and reliability of speed limit control. Attached Figure Description

[0014] In the attached diagram: Figure 1 This invention presents a circuit diagram of a forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar. Figure 2 This is a circuit diagram of the battery module proposed in this utility model; Figure 3 This is a circuit diagram of the electronic control module proposed in this utility model; Figure 4 This is a circuit diagram of the instrument color screen module proposed in this utility model; Figure 5 This is a circuit schematic diagram of the domain control module one proposed in this utility model; Figure 6 This is the circuit schematic diagram of the second domain control module proposed in this utility model; Figure 7 This is a circuit diagram of the fuse module proposed in this utility model; Figure 8 This is the circuit schematic diagram of the DC-DC module proposed in this utility model.

[0015] In the diagram: 1-Battery module, 2-Electronic control module, 3-Instrument display module, 4-Domain control module, 5-Fuse module, 6-DC-DC module, 41-Domain control module one, 42-Domain control module two. Detailed Implementation

[0016] Reference Figure 1 A forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar includes a battery module 1, an electronic control module 2, an instrument panel module 3, a domain control module 4, a DC-DC module 6, and a roof detection module for detecting whether the roof is indoors. The signal output terminal of the battery module 1 is connected to the signal input terminals of the electronic control module 2 and the DC-DC module 6, respectively. The signal output terminal of the electronic control module 2 is connected to a traction motor and a pump motor, both controlled by speed encoders. The signal output terminal of the DC-DC module 6 is connected to the signal input terminals of the instrument panel module 3, the domain control module 4, and the roof detection module, respectively. The signal output terminals of the roof detection module and the instrument panel module 3 are both connected to the domain control module 4 via a CAN bus. The signal output terminal of the domain control module 4 is connected to the battery module 1 and the electronic control module 2 via a CAN bus.

[0017] Clearly, based on the above: During forklift operation, the roof detection module continuously monitors whether a roof exists above the forklift and sends signals representing indoor and outdoor conditions to the domain control module via the CAN bus. The domain control module, based on the received indoor and outdoor condition signals, sends them to the electronic control module via the CAN bus. The electronic control module, in conjunction with speed encoder feedback, adjusts the output of the traction motor and pump motor, thereby limiting the forklift's speed to a reasonable range suitable for the current scenario. Through this coordination, this embodiment can automatically identify the forklift's indoor and outdoor operating conditions and achieve adaptive speed limit control without relying on external infrastructure. This effectively reduces the safety risks of speeding in indoor environments while maintaining vehicle operating efficiency in open outdoor areas.

[0018] In this embodiment, refer to Figure 2Battery module 1 includes a battery body, a first DC-DC chip, and a BMS battery management subsystem. The first positive output of the battery body is connected to the input terminal of the BMS battery management subsystem through the first DC-DC chip. Electronic control module 2 includes an electronic controller. The KSI port of the electronic controller is connected to the enable control terminal C of the first DC-DC chip.

[0019] Clearly, based on the above, the status of the forklift battery can be monitored and protected through the settings of the BMS battery management subsystem.

[0020] In this embodiment, refer to Figure 8 The DC-DC module 6 includes a second DC-DC chip. The second positive output of the battery body is connected to the B+ port of the power controller and the positive input port of the second DC-DC chip via the switch MR. The third positive output of the battery body is connected to the enable control terminal C of the second DC-DC chip via the emergency power-off switch and the key switch. The B- port of the power controller and the B- port of the second DC-DC chip are both connected to the negative terminal of the battery body.

[0021] Obviously, based on the above, the DC-DC module 6 converts the 80V voltage of the battery to 12V voltage, which facilitates the power supply for subsequent electrical appliances.

[0022] In this embodiment, refer to Figure 5 The roof detection module includes a roof radar and a laser rangefinder, both used for roof detection. The positive output terminal of the second DC-DC chip is connected to the positive input terminal of the roof radar and the laser rangefinder, respectively, and the negative output terminals of the roof radar and the laser rangefinder are both connected to the negative input terminal of the second DC-DC chip.

[0023] Specifically, roof-mounted radar has a better detection effect on roofs made of metal or concrete containing metal, while laser rangefinders are easily affected by indoor ambient light. By working simultaneously with both roof-mounted radar and laser rangefinders and comprehensively evaluating their outputs, the detection effect can be improved.

[0024] In this embodiment, refer to Figure 5 The domain control module includes a domain controller. The positive input terminal of the domain controller is connected to the positive output terminal of the second DC-DC chip. The roof radar and laser rangefinder are both connected to the domain controller via the CAN bus.

[0025] Obviously, based on the above: during the operation of the forklift, the roof radar and laser rangefinder will send the detected signals to the domain controller, which can then determine whether there is a roof above the forklift.

[0026] In this embodiment, refer to Figure 6The domain controller is also externally connected to a seat belt switch, a seat switch, a forward / reverse switch, a handbrake, a foot brake switch, an accelerometer switch, a horn, and a steering wheel angle sensor. The positive output terminal of the second DC-DC chip is connected to one end of each of the following switches: seat belt switch, seat switch, forward / reverse switch, handbrake, foot brake switch, accelerometer switch, horn, and steering wheel angle sensor. The other ends of these switches are connected to the signal input terminals of the domain controller.

[0027] Clearly, based on the above, the second DC-DC chip provides a unified low-voltage power supply to the seatbelt switch, seat switch, forward / reverse switch, handbrake and foot brake switches, accelerator switch, horn, and steering wheel angle sensor. When each component changes its state, it feeds back the corresponding status information to the domain controller's signal input in real time through loop opening / closing or signal changes. This allows the domain controller to synchronously collect multi-dimensional operational data, such as whether the driver is correctly seated and fastened their seatbelt, the vehicle's current forward / reverse gear, the engagement / disengagement status of the handbrake and foot brake, accelerator pedal operation, steering wheel angle, and horn activation. This arrangement achieves centralized power supply and unified acquisition of key safety switches and operational status quantities, simplifying the vehicle's wiring harness layout and reducing wiring complexity. Furthermore, it provides complete and reliable basic data support for the domain controller to execute vehicle start-up condition determination, speed limiting and intervention control under fault or abnormal operating conditions, and dynamic speed limiting strategies based on steering conditions. This ultimately improves the safety, control accuracy, and overall system stability during forklift operation.

[0028] In this embodiment, refer to Figure 5 The signal output terminal of the domain controller is connected to the negative input terminal of the second DC-DC chip via the indoor speed warning light.

[0029] Clearly, based on the above: when the domain controller determines that the forklift is in an indoor environment and triggers a speed limit policy based on information collected by sensors such as the roof detection module, it controls the indoor speed warning light to illuminate or extinguish, providing a direct reminder of the current indoor speed limit status. This setting allows the driver to receive a clear visual prompt through the warning light when entering indoor working conditions or when the system implements speed limit control, encouraging them to consciously control their speed and operating behavior, and enhancing the perceptibility and enforceability of the speed limit policy.

[0030] In this embodiment, refer to Figure 7 The fuse module 5 consists of multiple sets of fuses installed at the front end of the electrical appliance to protect the circuit.

[0031] To more clearly illustrate the implementation plan and its effects, we will use the attached diagram as an example: See attached document Figure 1-8 This system connects the 80V high-voltage battery to a DC-DC transformer via a fuse, where one path reduces the voltage to 12V to provide low-voltage power to the instrument panel, domain controller, and various sensors. The other high-voltage path serves as the power source input to the integrated electronic control unit (ECU). The battery integrates a Battery Management System (BMS) that transmits battery status information to the ECU via CAN signals. The CAN port of the ECU is connected to the CAN port of the domain controller, forming the vehicle's main communication network.

[0032] When the system is in operation, the domain controller can independently receive CAN signals from various sensors and, after comprehensive analysis, issue vehicle control commands to the integrated electronic control unit (ECU). Furthermore, the domain controller can also independently receive hardwired operation signals to directly control loads such as lights and horns. For example, the accelerator pedal provides an acceleration request signal to the domain controller, the turning sensor sends a speed limit request when turning, the roof-mounted millimeter-wave radar triggers a speed limit when it detects the interior roof, and the laser rangefinder also generates a speed limit command when it identifies the interior roof. At this point, the domain controller comprehensively judges all input speed limit values, selects the lowest limit speed as the final vehicle speed limit, and sends this final speed limit command to the integrated ECU via the CAN bus, achieving precise limitation of the vehicle's speed.

[0033] Environmental status input: For example, a millimeter-wave radar installed on the roof of a forklift continuously detects whether there is a roof above, and simplifies the determination result into a 1-bit status signal (e.g., '0x01' = indoor; '0x00' = outdoor), which is sent to the domain controller via the CAN bus.

[0034] Centralized logic judgment and instruction generation: Continuously monitors specific CAN messages from radar and speed limit messages from other sensors such as laser rangefinders. Logic judgment: The algorithm calculates the minimum value between 30% of the maximum indoor speed limit and other sensor-based speed limit logic. Essentially, this algorithm is a lookup table. if (OptPara.IndoorsHeight.indoorsFlag) { VCUctr.ControlFlag.tracCtrlFlag = 1; tracSpdPer=FunMin(300,tracSpdPer); / / For example: 30% of the indoor speed limit maximum speed is compared with the minimum value in the logic of other speed limits. } The domain controller calculates the tracSpdPer value and encapsulates it into a standard speed limit command message according to the CAN communication protocol predefined by the vehicle system and recognizable by the traction motor controller. Finally, it outputs this CAN command containing the specific speed limit percentage and sends it to the CAN bus periodically or triggered by events.

[0035] Dual-input cooperative control: a. Driver Intent Input: The driver expresses their desired vehicle speed via the accelerator pedal. The pedal sensor converts the pedal's opening angle (or position) into an analog or digital signal, representing the driver's desired torque or speed.

[0036] b. System input restrictions: If the domain controller determines that the vehicle is in an indoor state, input 30% of the original vehicle speed; if it determines that the vehicle is in an outdoor state, input 100% of the original vehicle speed. The system will encapsulate the original speed into a specific CAN message according to the CAN communication protocol defined by the traction motor controller and send it to the motor controller.

[0037] c. Final Execution: The traction motor controller, as the final execution unit, receives the two inputs mentioned above: From the pedal: Expected speed.

[0038] From domain controller: rate limiting ratio.

Claims

1. A forklift indoor and outdoor condition detection and speed limiting system based on millimeter-wave radar, characterized in that: The system includes a battery module (1), an electronic control module (2), an instrument color screen module (3), a domain control module (4), a DC-DC module (6), and a roof detection module for detecting whether the roof is indoors. The signal output terminal of the battery module (1) is connected to the signal input terminal of the electronic control module (2) and the signal input terminal of the DC-DC module (6). The signal output terminal of the electronic control module (2) is connected to a traction motor and a pump motor, both controlled by a speed encoder. The signal output terminal of the DC-DC module (6) is connected to the signal input terminals of the instrument color screen module (3), the domain control module (4), and the roof detection module. The signal output terminals of the roof detection module and the instrument color screen module (3) are both connected to the domain control module (4) via a CAN bus. The signal output terminal of the domain control module (4) is connected to the battery module (1) and the electronic control module (2) via a CAN bus.

2. The forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar according to claim 1, characterized in that: The battery module (1) includes a battery body, a first DC-DC chip and a BMS battery management subsystem. The first positive output of the battery body is connected to the input terminal of the BMS battery management subsystem through the first DC-DC chip. The electronic control module (2) includes an electronic controller. The KSI port of the electronic controller is connected to the enable control terminal C of the first DC-DC chip.

3. The forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar according to claim 2, characterized in that: The DC-DC module (6) includes a second DC-DC chip. The positive second output of the battery body is connected to the B+ port of the power controller and the positive input port of the second DC-DC chip through the switch MR. The positive third output of the battery body is connected to the enable control terminal C of the second DC-DC chip through the emergency power-off switch and the key switch. The B- port of the power controller and the B- port of the second DC-DC chip are both connected to the negative terminal of the battery body.

4. A forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar according to claim 3, characterized in that: The roof detection module includes a roof-mounted radar and a laser rangefinder, both used for detecting roofs. The positive output terminal of the second DC-DC chip is connected to the positive input terminal of the roof-mounted radar and the laser rangefinder, respectively, and the negative output terminals of the roof-mounted radar and the laser rangefinder are both connected to the negative input terminal of the second DC-DC chip.

5. A forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar according to claim 4, characterized in that: The domain control module (4) includes a domain controller. The positive input terminal of the domain controller is connected to the positive output terminal of the second DC-DC chip. The roof radar and the laser rangefinder are both connected to the domain controller via a CAN bus.

6. A forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar according to claim 5, characterized in that: The domain controller is also externally connected to a seatbelt switch, a seat switch, a forward / reverse switch, a handbrake, a foot brake switch, an accelerometer switch, a horn, and a steering wheel angle sensor. The positive output terminal of the second DC-DC chip is connected to one end of each of the seatbelt switch, seat switch, forward / reverse switch, handbrake, foot brake switch, accelerometer switch, horn, and steering wheel angle sensor. The other end of each of the seatbelt switch, seat switch, forward / reverse switch, handbrake, foot brake switch, accelerometer switch, horn, and steering wheel angle sensor is connected to the signal input terminal of the domain controller.

7. A forklift indoor and outdoor status detection and speed limiting system based on millimeter-wave radar according to claim 5, characterized in that: The signal output terminal of the domain controller is connected to the negative input terminal of the second DC-DC chip via an indoor speed warning light.

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