TI Action Camera and Handheld Gimbal Solutions

Jacktang

TI Action Camera and Handheld Gimbal Solutions [Copy link]

With the advent of the 5G era, short videos have become the hottest trend in the industry. While smartphones are being updated and replaced at an accelerated pace, action cameras and handheld stabilizers are gradually becoming popular among young people due to the diversity of application scenarios, as well as performance and price advantages.
1. Introduction to the action camera system
Compared with traditional digital cameras, action cameras use electronic image stabilization. During actual shooting, only part of the picture is captured. The built-in gyroscope and accelerometer are used to make a fuzzy judgment on the direction of camera shake, and the processor resources are used for calculation and to supplement the remaining picture, thereby producing an anti-shake effect. With the continuous development of processors, electronic image stabilization has become the mainstream anti-shake method for action cameras due to its cost advantage. The
detailed action camera system block diagram is as follows:

In the signal chain, the microphone and lens module collect audio and video signals, which are sent to the MCU for processing after passing through the corresponding codec. The user-defined anti-shake algorithm is used to restore the clear video. The
main components of the audio codec device are the analog-to-digital converter (ADC), the digital-to-analog converter (DAC) and the data interface bus, which are used between the codec and the microcontroller (MCU) or DSP. With the increase in system complexity and the decrease in size in portable applications, functional integration has become an attractive option for designers. Users can use I2C or SPI communication protocols to access the relevant registers for configuring the audio codec. The device can extract clear voice/multi-microphone arrays from low-level far-field signals in noisy environments. Some logic devices such as level conversion devices may also be required to match the level incompatibility between Flash or peripheral interfaces and processors. In the power
rail part, it is usually a 5V USB interface, which powers the system/charges the lithium battery through a charging chip. When there is no external power supply, the battery will provide power to the system through a high-efficiency DC-DC chip. In order to ensure the stability of image quality and the performance of MCU, low-noise LDO is usually used to power the lens module and the MCU clock.
In the sports camera system. The number of battery cells is mostly 1. With the pursuit of high-quality video, while the image quality and frame rate are improved, the power consumption of the processor will continue to increase. TI's charging chip can also provide power path management function, which can flexibly configure the relationship between power input, battery and system load during charging, and can also adjust the appropriate charging current according to the actual temperature through JEFET. A high-efficiency power supply solution can reduce the size of the system and extend the use time, and also reduce the design difficulty of developers.
Sports cameras have strict requirements on chip packaging and power consumption. TI's products are very rich. Here are a few ICs. The indicators of concern are mainly power consumption and packaging.
Summary of sports camera solutions [attach] 488905 [/attach]

2. Introduction to the handheld stabilizer system
The handheld stabilizer, also known as the handheld gimbal, is a derivative of the quadcopter gimbal. It transfers the technical application of the automatic stabilization coordination system used on the quadcopter to mobile phone (or camera) shooting. It is a high-tech portable mobile photography equipment. Compared with the traditional Steadicam-style mechanical stabilizer, the electronic stabilizer such as the handheld gimbal greatly simplifies the shooting difficulty for the photographer. After the built-in gyroscope sensor of the device detects the position and direction of the three-axis shake, the MCU processes this data and drives the three motors of the pitch axis, roll axis and heading axis. The rotation generates a force opposite to the shake of our hands, thereby offsetting the vibration of the picture and achieving the stability of the video shooting.
The detailed block diagram of the handheld stabilizer system is as follows:

Handheld stabilizers also have strict requirements on chip packaging and power consumption. The following is a summary of TI's solutions for handheld stabilizers. Summary of
Handheld Stabilizer Solutions

For the power rail part, the USB interface is generally used to power the system with a charging chip/charge the lithium battery. Considering the efficiency of the gimbal brushless motor drive, multiple lithium batteries are usually used to power the motor drive. The higher bus voltage can also reduce the current in the main circuit and reduce unnecessary line loss. In addition, in order to ensure the performance and standby time of the system, it is also necessary to use an efficient buck chip to power the processor, and a low-noise LDO to provide a reference for the processor clock.
Signal chain part: The offset of the brushless DC motor position is detected by two linear Hall sensors. The processor will detect the offset of the position and direction of the three-axis jitter and execute the corresponding algorithm. The driver chip is used to drive the brushless motor to compensate for the offset, and finally achieve stable video shooting.

For camera applications, the TI website also has a wealth of design solutions for reference, including product block diagrams, reference designs, popular products, etc. For more camera information, please see the link:
http://www.ti.com.cn/solution/cn/digital-still-camera

alan000345

After reading this, I finally understand how sports cameras are designed. Thanks for sharing.

宋元浩

Thanks for sharing

freebsder

It's quite amazing. I remember there was a compound eye camera, the kind that didn't need to focus at all, and the camera of each eye could restore the scene by taking a picture.