Payload Development Standards
To ensure the safety of the aircraft during flight missions with payload devices, please follow the Autel Robotics payload development standards when using the PSDK to develop payload devices.
Hardware Interface Standards
Note：
- Do not short-circuit the pins of the aircraft or hardware platform.
- Do not connect the aircraft to a power output system or input current to the aircraft.
- The payload capacitor must be ≤500uF. If it exceeds this threshold, the aircraft will trigger a short-circuit protection during the power-on moment, and the SDK power output will be turned off.
- The protection current is 4A (3A for P-Port Lite). If the current limit is exceeded, the aircraft will cut off the power within 5ms to ensure flight safety.
- The P-Port Lite interface is only supported by the EVO Max series multirotor aircraft.
| Interface Name | Interface Function | Requirements |
| P-Port Interface | Power Output | EVO Max Series Rated Voltage: 12.8 - 17V Rated Current: 4A |
| PPS Pin Voltage | 3.3A | |
| UART Pins | Must follow 3.3V TTL protocol | |
| USB Interface | Must follow USB 2.0 protocol | |
| P-Port Lite Interface | Power Output | EVO Max Series Rated Voltage: 12.8 - 17V Rated Current: 3A |
| USB Interface | Must follow USB 2.0 protocol |
Interference Compatibility Requirements
| Interference Type | Compatibility Requirements |
|---|---|
| Light Flicker | The light flicker frequency must not be in the range of 0.5 ~ 50Hz |
| Light Wave Emission | - The light source should ideally be around 5000K (white light) or near infrared - Single red, green, or blue light is prohibited |
| Magnetic Field | - Strong magnetic substances should not be carried by load devices, magnetic heading interference < 0.5uT - High-intensity alternating magnetic fields should be avoided |
| Electromagnetic Noise | Avoid frequency bands: 0.8 ~ 1.5GHz, 2.2 ~ 2.7GHz, 4.8 ~ 6.0GHz - Equivalent isotropic radiated power (EIRP) must be less than 1W |
| Acoustic Noise | Avoid frequency band: 2.5 ~ 4KHz |
Structural Design Standards
Note：
- To avoid damage to both the aircraft and the payload device caused by the aircraft's flight inertia, such as collision with the battery compartment and propellers, please design the payload device's size reasonably.
- To prevent the payload device from affecting the aircraft’s moment of inertia, please minimize the size of the payload device.
General Structural Standards
Note：
- For more detailed and accurate data, please refer to the user manual for the corresponding aircraft model. The user manual can be downloaded from the Autel Robotics official website for the respective model.
| Structural Parameter | EVO Max Series |
|---|---|
| 3D Model File | Contact the SDK Technical Support Team for access |
| Structural Interference | During flight missions, the payload device must not collide with the aircraft's components: arms, propellers, or gimbals, and must not obstruct the field of view (FOV) of the visual and radar systems. |
| Vibration | After the aircraft powers on, the payload device must not cause vibrations that affect the IMU while the aircraft is stationary, ensuring normal initialization and takeoff. |
| Shell Temperature | -30℃ to+70℃ |
| Maximum Takeoff Weight | ≤1890g (EU C2 level), ≤1999g (Other regions) |
| Height | The height of the PSDK payload must not exceed 70mm above the mounting hole. |
| Motion Path | The motion path of the payload device must not obstruct sensors: 1. Front stereo vision system FOV: 67° × 85° (horizontal × vertical), perceivable range <30m 2. Rear stereo vision system FOV: 67° × 85° (horizontal × vertical), perceivable range <25m 3. Upward stereo vision system FOV: 120° × 185° (horizontal × vertical), perceivable range <30m 4. Downward stereo vision system FOV: 120° × 185° (horizontal × vertical), perceivable range <35m 5. Front and rear millimeter-wave radar detection range: ±60° × ±30° (horizontal × vertical), perceivable range 0.3 - 50m 6. Upward millimeter-wave radar detection range: ±60° × ±30° (horizontal × vertical), perceivable range 0.3 - 20m 7. Downward millimeter-wave radar detection range: ±60° × ±30° (horizontal × vertical), perceivable range 0.15 - 80m |
| Center of Gravity | Mount the payload device using the body’s mounting holes; the payload's center of gravity must lie between the front and rear mounting holes, with the overall aircraft's center of gravity remaining within 1cm of the midpoint of the rear mounting hole. If the center of gravity shifts forward, it must be <2mm; If the center of gravity shifts backward, it must be <8mm. |
Custom Data Transmission Standards
| Channel Type | Transmission Direction | Rate Limitation |
| Command Channel | Mobile App -> Payload Device | ≤2048B/s |
| Payload Device -> Mobile App | ||
| Cloud (e.g., cloud API) -> Payload Device* | ||
| Payload Device* -> Cloud (e.g., cloud API) | ||
| High-Speed Data Transmission Channel | Payload Device -> Mobile App | Single Gimbal: <8192Kbps Multiple Gimbals: Each gimbal transmission rate ≤4096Kbps |
Tip：
- The connection between the cloud (e.g., cloud API) and the payload will be supported once the interconnection functionality is available in future updates.
Video Stream Transmission Standards
When developing camera-related payload devices with PSDK, the following H.264 encoding standard must be selected.
Features:
A widely used and easily accessible H264 stream format.
When sending the stream in this video format, it will be transparently transmitted through the aircraft to the App for decoding, with real-time bitrates not exceeding the feedback value.
SEI content in this format can be transmitted to the App.
Requirements For camera-related payload devices developed with PSDK using the H.264 standard, the following key configuration information must be considered:
| Key Frame | H.264 Standard Item | Value |
|---|---|---|
| Video Resolution | - | Maximum 1280 × 720 |
| Frame Rate | - | Maximum 30 fps |
| Bitrate | - | Maximum 8 Mbps |
| Recommended Aspect Ratio | - | 4: 3 |
| GOP Encoding Structure | - | - |
| Level Number | Level Number | ＜5.1 |
| profile_idc | 7.3.2.1.1 | Baseline=66，Main=77，High=100 |
| YUV420 Format | 7.3.2.1.1 | chroma_format_idc=1 |
| 8Bit Video | 7.3.2.1.1 | bit_depth_luma_minus8=0 bit_depth_chroma_minus8=0 |
| Encoder Custom Scaling Matrix Not Allowed | 7.3.2.1.1 7.3.2.2 | seq_scaling_matrix_present_flag=0 pic_scaling_matrix_present_flag=0 |
| Frame Format Only, Field Encoding Not Supported | 7.3.2.1.1 | frames_mbs_only_flag=1 |
| Only P-Frames and I-Frames Allowed, with Single Reference Frame for P-Frames | 7.3.3 7.3.2.2 7.3.3 | slice_type =0 or 2 num_ref_idx_l0_default_active_minus1=0 num_ref_idx_active_override_flag=0 |
| Multi-Slice Group Not Supported | 7.3.2.2 | num_slice_groups_minus1=0 |
Note：
- When using the H.264 encoding standard, the GOP encoding structure must use Period I (Intra-coded frames, with an IDR frame inserted every 1 second to ensure image data can be recovered if lost).