A CAN-bus solution for unmanned delivery

1. Unmanned delivery industry trends

Affected by the domestic epidemic and the promotion of the "new infrastructure" policy, the unmanned delivery industry has developed rapidly. In the previous Wuhan epidemic prevention war, many well-known companies put unmanned delivery vehicles into use, realizing "contactless" express logistics delivery and transportation of protective materials.

Unmanned delivery refers to the lack of or minimal human involvement in the circulation of goods. In simple terms, it is a simple version of autonomous driving, with artificial intelligence  AI as the core, combined with high-precision maps and various sensors and other technologies, to achieve the purpose of improving efficiency and reducing costs by replacing human labor with machines or human-machine collaboration. Figure 1 shows a schematic diagram of an unmanned delivery vehicle.

Figure 1 Schematic diagram of unmanned delivery vehicle

2. CAN interface expansion solution

At present, the unmanned delivery part execution components and walking motors all use CAN-bus fieldbus communication, while high-end AI ICs and industrial computers lack CAN interface design, such as ZLG's M1808. The redundant interfaces on the AI ​​industrial computer can be used to expand multiple CAN interfaces to achieve communication between the RCU units of the car. As shown in Figure 2, based on this requirement, the following interface expansion solutions are introduced:

Figure 2 CAN interface expansion solution

As shown in the figure above, the MiniPCIe interface CAN card, PCIe interface CAN card, Ethernet to CAN module and other series of products are high-performance CAN interface cards developed by ZLG based on different forms of interfaces. With AI industrial computers, up to 8-way electromagnetic isolation 3500VDC CAN port expansion can be achieved. In addition, these CAN cards support drivers of any system and can be developed in Windows, Linux and other systems. The message receiving capacity is up to 14,000 frames/second, which is an industrial-grade product design.

3. How to achieve remote monitoring of unmanned delivery vehicles?

As the unmanned delivery industry continues to advance, the need for bus data recording and real-time positioning is obviously particularly important. At the same time, both the test vehicle and the road test need to continuously optimize the path and algorithm. In order to obtain the CAN-bus data of the car in real time and understand the operating status of the unmanned delivery car, as shown in Figure 3, ZLG provides industry users with the "CANDTU series products + ZWS-CAN smart cloud" solution to address this industry pain point.

Figure 3: Remote monitoring of unmanned delivery vehicles

The CANDTU series of products, also known as "car black boxes", support long-term recording, conditional recording, pre-trigger recording, and timed recording, and have IP57 protection and vibration resistance. As shown in Figure 4, the product can record CAN data locally or transmit data to the cloud via 4G to achieve real-time data monitoring or data download. In addition, it has GPS/Beidou positioning function to locate the car in real time. You only need to use the CANDTU configuration tool to configure the above functions, and you can convert the recorded files into formats supported by various analysis software.

Figure 4 Schematic diagram of CANDTU series products

4. Troubleshooting of unmanned delivery vehicles

The motor of the unmanned delivery vehicle communicates with each actuator through the CAN-bus. When a fault occurs, how can we quickly locate the problem and troubleshoot it? As shown in Figure 5, ZLG provides CANScope analyzer products and portable PA2000mini power analyzer for this purpose. For the underlying line control fault problem, the CANScope analyzer can quickly locate the fault from the physical layer, link layer and application layer to optimize the line control design. Based on the motor efficiency and the power consumption control requirements of the whole machine, the portable PA2000mini power analyzer can easily perform on-board testing.

Figure 5: Troubleshooting solution for unmanned delivery vehicles

As shown in Figure 6, the CANScope bus comprehensive analyzer is an ultimate CAN bus tool that integrates an oscilloscope, a network analyzer, a protocol analyzer, and a reliability test tool. Through various analysis software plug-ins such as synchronous viewing of data waveforms and eye diagrams, it can analyze and locate faults at multiple levels from the physical layer and data link layer, easily find the cause of the fault, and solve all CAN problems in one stop.

Figure 6 CANScope analyzer schematic diagram

As shown in Figure 7, PA2000mini is a power analyzer that can perform mobile and portable measurements. While the size and weight are further optimized, the power measurement accuracy can be guaranteed to be 0.05%. It has a large storage capacity of 120G and can collect all phases synchronously. In addition, the PA2000mini power analyzer is small in size and has a battery that can work continuously for 3 to 4 hours. It is very convenient for testing motor efficiency and other tests at the unmanned delivery vehicle test site.

Figure 7 PA2000mini product diagram