Nationz and SIAT Unveil Integrated Humanoid Robot Joint Motor Drive-and-Control Solution
Nationz and SIAT have released an integrated humanoid robot joint motor drive-and-control solution built on the N32H785 heterogeneous dual-core MCU, achieving a 20 kHz current loop and a 106 ms average 0-100 rpm step response — now delivered as a production-ready solution rather than a reference design.
On 23 September 2026, Nationz Technologies announced an integrated humanoid robot joint motor drive-and-control solution developed jointly with the electric drive systems team at the Shenzhen Institute of Advanced Technology (SIAT), Chinese Academy of Sciences. The solution is built around Nationz's heterogeneous dual-core MCU, the N32H785, and integrates the drive controller, a frameless torque motor, dual absolute encoders, the communication module and the gearbox inside a single joint. Nationz frames the result as a production-oriented engineering effort — a reference platform developers can adapt, rather than a paper design.
Why a heterogeneous dual-core architecture
Single-core joint controllers run into a structural conflict. Field-oriented control needs microsecond control loops, while the communication stack cannot afford to drop data. When both compete for the same core, determinism and stability are hard to guarantee. After repeated joint debugging, the SIAT team concluded that the bottleneck in joint control usually sits in the compute architecture, not the control algorithm.
The N32H785 separates the two workloads across cores:
- Cortex-M7 at up to 600MHz, with double-precision floating point and DSP instructions, dedicated to FOC motor control, the torque/speed/position three-loop scheme, dual-encoder data processing and safety functions.
- Cortex-M4F at up to 300MHz, dedicated to CAN FD, EtherCAT and serial communication.
The cores exchange commands and status through on-chip SRAM and synchronise with SEMA4 hardware semaphores. In Nationz's phrasing, one core handles the muscle, the other the nerves — heavy communication traffic does not slow the motor control loop.
On-chip resources built for high-performance control
- Two 16-bit ultra-high-resolution timers (SHRTIM1/2, up to 100 ps resolution) and four 16-bit advanced timers (up to 3.3 ns), generating the complementary PWM signals a three-phase inverter bridge requires.
- Three 12-bit 5 Msps ADCs, four high-speed analogue comparators and six 12-bit DACs, covering phase-current sampling, bus-voltage monitoring and fast fault detection.
- Eight CAN FD channels and two Ethernet MACs; the EC variant (N32H785EC) integrates an EtherCAT slave controller.
- 2MB or 4MB on-chip Flash and 1504KB SRAM, enough to hold control algorithms, protocol stacks and runtime data.
- An operating range of -40°C to +105°C, with SRAM ECC, independent and windowed watchdogs and temperature sensing for reliability.
High integration reduces the number of external control components and shortens signal paths — a direct gain in board area, weight and cost for space-constrained joint electronics.
Measured results from full-load bench testing
- Rated torque of 20 N·m and peak torque of 60 N·m, covering the main output range for whole-robot motion.
- A 20kHz current loop working with the torque, speed and position loops to deliver millisecond-level torque command response.
- 0→100rpm speed step: average response time of 106ms, maximum overshoot of just 4.43%, speed ripple within ±5%.
- Position tracking: maximum error of 0.01 rad (about 0.573°), average error of 0.54°; a ±360° move completes within one second.
Nationz puts the precision figure in practical terms: not crushing an egg when grasping it, not spilling water when handing over a cup — that is what roughly half a degree of position control buys you.
From reference design to deliverable solution
- An integrated mechanical structure places control, drive, sensing, communication and gearing inside the joint, shortening the signal chain.
- Dual absolute encoders sample position feedback from both the motor side and inside the gearbox, giving the joint a fuller picture of where it is positioned.
- Serial, CAN FD and EtherCAT are all supported, so robot OEMs can connect the joint to whichever bus their platform already uses.
The work did not start here. Nationz leads the "Robot Joint Integrated Drive-and-Control Chip" project under China's 14th Five-Year Plan national key R&D programme for intelligent robotics, collaborating with Fudan University, Chongqing University, SIAT, Huazhong University of Science and Technology, UBTECH and others; the project passed its mid-term review in July 2025, and the two parties signed a cooperation agreement on 23 April 2025.
Industry context matters for planning: TrendForce forecasts global humanoid robot shipments will exceed 50,000 units in 2026, up more than 700% year on year, with Chinese manufacturers holding roughly 97% share in the first half. Joint modules account for more than half of robot hardware cost.
HSY Perspective
When robotics customers come to us, the question is rarely which MCU has enough compute. It is how long after samples arrive the joint will actually turn. The FOC tuning, encoder fusion and bus protocol in between eat more engineering time than the selection itself. That is where this solution earns its keep: it is no longer a reference design but a deliverable. Along with N32H785 samples we can hand over the bench-validated solution package, which shifts your effort from "can we make it run" to "does it hold accuracy with our joint parameters".
Three things are worth settling early. With the M7 running the FOC control loops and the M4F handling communication and safety monitoring, the control period does not drift as bus load rises — a point that matters to anyone synchronising multiple joints. If you only need single-axis control and cost is the constraint, the N32H47x family serves as a lower-cost joint-level controller. And because the high-resolution timers, 5 Msps ADCs, comparators and DACs sit on-chip, component count and PCB area both come down, which counts for something in a joint that is small and weight-sensitive.
On real projects, power class, encoder type (BISS-C, SSI and others) and robot bus (EtherCAT or CAN FD) vary widely. We suggest tuning parameters on the reference platform until they are right, then freezing the production form. For samples, dev boards or the full technical package, send us your joint parameters and bus choice and we will put together a device combination that fits the machine.
Sources: Nationz Technologies announcement "Jointly with SIAT, Nationz releases a new-generation joint motor drive-and-control solution" (republished by Leaderobot, https://wx.leaderobot.com/news/9837, 23 September 2026); Nationz official news, "Mid-term review of the Robot Joint Integrated Drive-and-Control Chip project" (https://www.nationstech.com/about/news/information/6211.html, 14 July 2025).
