10) must work harder to maintain the negative −10 RPM slip, thus applying more negative torque.

It is important to note that in both the driving and braking scenarios described, the same hardware is used, and only the motor's speed relative to the wheel changes its sign. The friction brake (50) is used in a continuous slip manner rather than as an on/off brake. Because the slip speed is fixed and small, the friction interface (between the brake pad and ring gear/disc) experiences only minimal movement while transmitting torque. As a result, the friction brake effectively modulates torque without significant wear or heat, acting analogously to a clutch. The motor's role is to maintain the set slip speed; it inherently provides whatever torque is necessary (within its capabilities) for doing so. This elegant control means that the system does not require explicit measurement or feedback of torque. The motor current or effort adjusts to whatever level is needed to counter the braking force at the ring gear.

Closed-Loop Slip Control (FIG. 4): Reference is now made to FIG. 4, which is a block diagram of a closed-loop control system for maintaining a target slip speed in a single-driven output configuration (which is illustrated in FIG. 1). FIG. 4 illustrates a control loop diagram for a single-wheel system. The control loop diagram (400) shows the motor speed (om) feedback and wheel speed (ωw) input being compared to produce an error (414) that is used to control motor torque (417), thereby regulating slip. The speed controller (416) uses feedback from the wheel speed (ωw) and motor speed (ωm) to regulate this slip condition. A wheel speed sensor (408) provides the wheel's angular velocity (ωw) (for example, derived from wheel (34) rotation or ABS sensors already present in a vehicle). Set Point controller (410) computes a target motor speed (set point, SP) equal to the wheel speed (ωw) (multiplied by the gear ratio) plus a desired slip offset. The desired slip offset or the predetermined rotational speed offset, can be positive (for drive) or negative (for braking), typically a fixed RPM value, e.g., ±10 RPM or a small percentage of the wheel speed. The actual motor speed (om) (process value, PV) is measured by a motor speed sensor (420) or by the motor's internal encoder. The speed controller (416) compares (om) to the target SP (at operation (412)) and computes an error (414) (e.g., by calculating the sum of SP−PV). The speed controller (416) then adjusts the motor's input (for example, voltage or current) to drive this error (414) toward zero. If the motor (e.g., motor (10)) is too slow (error is positive), the speed controller (416) increases motor torque to speed it up; if the motor is too fast (error is negative), speed controller (416) commands regenerative braking torque to slow it down. In effect, the motor constantly tries to follow the moving target (i.e., wheel speed±offset). The friction brake's pressure is not directly controlled by this loop (400); instead, the brake's pressure is typically commanded by the driver's action (or another higher-level control input), and it influences the outcome by changing how much torque is required to maintain the slip. This closed-loop speed control (400) is high-response and can adjust motor torque very rapidly, which is important for maintaining stability and responsiveness. Because the system operates on maintaining a speed difference rather than a specific torque, it inherently avoids sudden jumps in torque—any increase in brake force smoothly translates to an increase in motor torque, and vice versa, in a proportional manner.

Symmetric Drive and Brake Operation: The operation described hereinabove is symmetric with respect to driving and braking. The transition from drive to regenerative braking is simply a matter of the motor's target to cross the actual wheel speed (ωw). For example, if the slip target is ±10 RPM, commanding a +10 RPM slip (i.e., motor is to rotate faster) will pull the vehicle forward, and commanding a −10 RPM slip (i.e., motor is to rotate slower) will slow the vehicle down. If the driver is applying a certain brake pressure and the motor slip target is gradually moved from +10 to −10, the wheel will smoothly go from receiving power to delivering power to the motor (regen) without any discontinuity. This gives the vehicle a very natural feel, akin to an engine providing propulsion when accelerating and engine braking when decelerating, all using the same connection. Importantly, if the driver completely releases both the throttle and the brake, the speed controller (416) can set the motor torque to zero, meaning the motor simply idles to a standstill; in this state, no torque is exchanged and the vehicle coasts freely. This behavior addresses the coasting drag problem—unlike a traditional direct-coupled motor, which would cause drag when unpowered, here the motor idles at zero speed with no resistance.

Motor-Based ABS and Traction Control: The system's reliance on motor speed control enables built-in ABS and traction control functionality. As the wheel-speed approaches the motor-speed—indicating the collapse of the desired slip target—the system infers an impending loss of traction. To maintain stability, it dynamically limits the motor's rate of acceleration or deceleration, thereby preserving a slip margin between the motor and wheel speeds. This continuous adjustment ensures controlled slip and effective torque modulation under varying surface and load conditions, without requiring additional sensors or mechanical subsystems. The electric motor (10) acceleration and deceleration are selectively limited based on indicators of potential traction loss, such that a controlled slip margin is maintained to prevent wheel lock or spin.

Multi-Wheel Drive with Shared Motor (FIG. 2 & FIG. 5): Reference is now made to FIG. 2, which is a schematic diagram of a dual-driven output drive system (200) using a single electric motor and two planetary gearsets (one per wheel) with a shared brake control. The disclosure extends to multiple driven wheels, and not just to a single wheel as described hereinabove. FIG. 2 shows an embodiment with two driven wheels, a left wheel-L (34) and a right wheel-R (35), using one motor (10). In this configuration, each wheel (34, 35) has its own planetary gearset: a left-side sun gear (20) and right-side sun gear (21), which are both driven by the single motor (10). For example, the motor's shaft (11) may be connected to both sun gears (20, 21) via a common member, i.e., shaft (11) or through a splitter gear (not shown). The left wheel (34) is attached to the left planet carrier (32), and the right wheel (35) is attached to the right planet carrier (33). The left ring gear (40) is braked by a left brake caliper (50), and the right ring gear (41) is braked by a right brake caliper (51). In the embodiment of FIG. 2, both brake calipers are actuated together by a shared hydraulic circuit, e.g., a single master cylinder (54) connected to a brake pedal (56) and a drive pedal (57). The single master cylinder (54) splits via two lines (52) feeding both calipers (50) and (51). Thus, both ring gears (40, 41) receive the same brake pressure simultaneously.

When the motor (10) is commanded to maintain a slip relative to the average wheel speed, the system will distribute torque between the two wheels as needed. FIG. 5 illustrates the control logic for this multi-wheel scenario. FIG. 5 is a block diagram of a closed-loop slip control system for a multi-wheel (e.g., two-wheel) configuration. FIG. 5 illustrates how the Set Point controller (510) uses a clamped average of multiple wheel speeds to set the motor's target speed, ensuring balanced slip and preventing excessive spin or lock on either wheel.

The left wheel speed ωw_L and right wheel speed ωw_R are both measured by a corresponding wheel speed sensor, i.e., left wheel speed sensor (508) for the left wheel (34) and right wheel speed sensor (506) for the right wheel (35). The Set Point controller (510) computes a reference speed or target speed SP for the motor (10), as a function of the rotational speeds of the driven outputs. For example, the function could be a simple average (ωw_avg=(ωw_L+ωw_R)/2) plus the slip offset. In practice, to ensure stability, a clamped average or biased selection may be used: for example, in regenerative braking mode, the Set Point controller (510) might use an average limited to about 20% below the faster wheel, so that it does not attempt to brake any wheel to a much slower speed than the fastest wheel which has best traction (preventing wheel lock-up). In drive mode, it might use an average limited to about 20% above the slower wheel so as not to overspin a wheel that has lost traction. This approach of clamping ensures one wheel slipping excessively will not result in the loss of traction typical to open differentials. The motor's actual speed (PV) in operation (420) is compared by the speed controller (416) to the target speed SP, in operation (412), and the speed controller (416) adjusts torque as described for the single-wheel case hereinabove. That is, the reference speed SP is limited to prevent any one output from exceeding a slip threshold, thereby simulating a limited-slip differential behavior among the plurality of driven outputs.

The effect of this control in FIG. 2 is that if one wheel starts to slip (loses traction), its speed will rise relative to the other wheel. The Set Point controller (510), using an average of wheel speeds, will adjust the motor target speed in response to that average speed, but since the average function is capped, i.e., limited, the motor target speed will only rise modestly as limited by the cap. The slipping wheel will spin at the motor speed, and the majority of the brake reaction torque will automatically go into the wheel with more grip because that wheel isn't spinning freely; it resists the motor's slip, drawing more torque. That is, the system (200) naturally allocates more torque to the slower wheel (the one with traction) and limits torque to the faster wheel (the one slipping or with less traction). This behavior mimics a limited-slip differential without needing complex clutch packs or electronics between wheels.

In normal operation on a high-traction surface, both wheels (34, 35) will rotate at nearly the same speed. The Set Point controller (510) will see nearly equal wheel speeds and use their average plus slip for the target speed SP. Both wheels (34, 35) will receive equal torque because the brake force on both ring gears (40, 41) is the same and both wheels (34, 35) resist similarly. When the vehicle is turning, the wheels (34, 35) inherently rotate at different speeds, such that the outside wheel, i.e., the wheel farther from the turning point, goes faster. In this case, the planetary gearsets (30, 31) allow differential action: the faster wheel's gearset will experience slightly less slip internally than the slower wheel's gearset. The slip speed between the motor and the driven output (e.g., a wheel) is maintained at a fixed or variably adjusted value, and the target slip speed is optionally increased or decreased based on operating conditions including but not limited to turning behavior, load distribution, thermal considerations, or efficiency optimization. Optionally, as the turn gets tighter indicated by the faster wheel approaching motor speed the target slip speed can be gradually increased to support the turn and as the turn gets wider the target slip speed can be gradually reduced to maintain efficiency. The driver perceives normal differential behavior, with the added benefit of automatic traction control if one wheel loses grip.

In some embodiments, the gearsets for each of the plurality of driven outputs, e.g., wheels (34) and (35), are of different topologies and ratios.

Independent Wheel Brake Control (FIG. 3): Reference is now made to FIG. 3, which is a schematic diagram of a dual-driven output drive system similar to FIG. 2, but with independent braking control for each driven output via separate brake lines and a brake pressure modulator, enabling individual wheel slip control (e.g., for ABS or torque vectoring). In an alternative multi-wheel embodiment illustrated in FIG. 3, the system (300) includes separate control of the brake mechanisms on each wheel (35, 35). This embodiment adds a brake pressure modulator (55) or any similar device that can independently adjust the pressure in the left and right brake lines (52 and 53, respectively), even if they originate from the same master cylinder (54). The motor (10) and planetary gear (30, 31) connections remain the same as in FIG. 2, which comprises motor (10) driving sun gears (20 and 21); wheels (34, 35) connected to carriers (32, 33); brakes connected to ring gears (40, 41) via calipers (50, 51). However, in the embodiment illustrated in FIG. 3, a control system can vary the brake pressure at each caliper (50, 51) separately. This allows finer control, such as anti-lock braking and active torque vectoring.

For instance, if during a braking event the left wheel (34) starts to approach lock-up (indicated by ωw_L dropping rapidly to motor speed, adjusted by gear ratio, without slip), an ABS algorithm can momentarily reduce pressure to the left caliper (50) via the modulator (55) to prevent that wheel from fully locking. It is noted that the speed of a “locked” wheel is equal to motor speed, not zero. The right wheel's brake can remain engaged as normal. The motor (10) in this scenario is providing regenerative braking torque through both gearsets, but by relieving pressure on the left side, the left wheel (34) is allowed to regain some traction and avoid skidding, all while the right wheel (35) continues to brake harder. Because the motor's slip target would be set based on the wheels, e.g., the fastest wheel to avoid any wheel locking, as per the clamped-average logic (see above description of FIG. 5), the motor (10) will adjust to the new conditions seamlessly. The outcome is that each wheel maintains a controlled slip ideal for maximum deceleration without lock-up, achieving superior ABS functionality with essentially the same hardware plus a small pressure control unit modulator (55).

In drive mode, independent control of brake pressure can similarly allow torque vectoring or stability control. By increasing brake pressure on one side, the system (300) can send more driving torque to that wheel, since the side with more brake effectively “drags” more, the motor (10) reacts by pushing harder. This could help, for example, to correct an understeer or oversteer condition by biasing torque distribution, or to enhance cornering by driving the outer wheel more than the inner wheel deliberately. Importantly, these advanced functions are achieved without needing multiple motors or complex differentials, but rather they are a straightforward extension of the slip-control concept with added brake control logic.

Whether using a shared brake line (FIG. 2) or independent brake lines (FIG. 3), the system of the present disclosure maintains the benefit of not requiring any torque sensors. The coordination between wheels is achieved through mechanical means (the gearsets and the slip dynamics) and simple speed sensing. This simplicity improves performance and reliability and reduces cost compared to current solutions.

Friction Brake Considerations: The friction brake mechanisms used in systems (100), (200) and (300) can be conventional vehicle brakes—for example, disc brakes with calipers and pads, drum brakes, multi-plate clutch or brake pack, a motor, a wet multi-plate brake, or any equivalent device capable of controllably resisting rotation. Since the brake is used constantly but primarily to create a resistive torque under slow slip, it operates in a very favorable condition: low relative velocity and typically moderate force. This is quite different from a standard braking scenario, which is often defined by high speed and high energy dissipation in a short time. Therefore, the systems of the present disclosure can take advantage of materials and designs optimized for continuous slip. For instance, pads made of sintered metals or Kevlar-based composites might be used because they handle continuous friction well and have low wear at low temperatures. In heavy-duty or long-life applications, a wet brake system (immersed in fluid) could be employed to further reduce wear.

Control Simplicity and Brake Blending: In contrast to conventional brake blending systems, which coordinate torque between independent friction brakes and regenerative motors, the present disclosure unifies all torque delivery and absorption through a single mechanical interface. Braking and propulsion are both mediated by controlled motor slip against a friction brake within the planetary gearset, eliminating the need to synchronize two separate torque sources. This architecture avoids the calibration complexity, latency, and instability associated with traditional brake blending. Because the motor torque is inherently modulated in response to brake force, transitions between drive and regenerative braking are seamless and sensor-minimal. The result is a simpler, more robust system that delivers smoother performance and higher overall control fidelity. The motor and brake essentially perform a mechanical negotiation: the brake tries to hold the ring gear, the motor tries to overcome or succumb to that hold by maintaining slip, and the wheel in between reacts accordingly.

Safety: There is an inherent failsafe in the system of the present disclosure: if the motor short-circuits and freezes, brake pressure will not be applied (or immediately stopped), enabling true mechanical disengagement that will prevent a dangerous sudden deceleration of the vehicle . . .

User Inputs and Interface: In all of systems (100), (200) and (300), the exact way a driver commands drive or braking torque can be adapted to the vehicle type. In one interpretation, pressing the accelerator could signal the set point controller to apply a positive slip (drive mode) and also possibly engage a mechanism to apply pressure to the brake calipers. Alternatively, a one-pedal interface can be implemented, automating both brake and drive according to pedal position. Alternatively, as conceptually shown in FIG. 1, there could be two pedals (56 and 57, FIG. 3) that both connect to the brake system: one labeled or functioning as a “brake” (for regen-braking) and the other as a “drive”. Both pedals actually apply brake pressure, but trigger the motor to brake or drive accordingly. This dual-pedal approach is unconventional in cars but it is optionally suitable for simple vehicles such as ATVs and it illustrates the symmetry of the system, i.e., that both pedals do the same thing-apply pressure to the brake caliper, but the Set Point controller interprets one as a command to enter drive mode (i.e., to implement a positive slip) and the other as a command for brake mode (i.e., to implement a negative slip).

Scalability: The architecture of the present disclosure is highly scalable and adaptable to a wide range of on-road, off-road and industrial configurations. A single motor can drive multiple driven outputs, e.g., wheels, axles, or axle groups, either individually, in multiples, through respective gearsets or through at least one conventional mechanical differential. For example, in a heavy-duty truck, the system may be installed between two drive axles with a standard differential on each, delivering coordinated torque control without multiple traction motors. The same principles extend to rigid-axle applications such as rail vehicles, or to industrial machinery that powers banks of rollers or drive wheels. In all cases, the localized brake-and-slip module at each gearset provides precise torque modulation with minimal mechanical complexity.

Sensorless Brake Force Estimation via Motor Torque Feedback: A notable feature of the system is its inherent ability to estimate brake force without the need for dedicated pressure or force sensors. Because the motor is operated in a closed-loop speed control mode to maintain a constant slip relative to the wheel, the torque output of the motor is directly proportional to the resisting force applied by the brake. This relationship allows the system to infer real-time brake force by reading motor current or torque response, providing a passive and accurate measure of braking effort. This capability enables advanced diagnostics, predictive maintenance, and intelligent control functions such as load balancing or surface condition inference, all without adding sensors to the brake circuit.

Motorcycle Embodiment (FIG. 6): FIG. 6 depicts a specific embodiment tailored for a motorcycle, which demonstrates the flexibility of the invention in a two-wheeler vehicle context. FIG. 6 illustrates a dual-mode operation where the motor drives the wheel directly in one direction (high gear) and through the slip-controlled planetary gearset in the opposite direction (low gear with regenerative braking), as well as the associated control inputs (throttle, brake pedal, and lever).

In a motorcycle, packaging and control feel are critical. The planetary gearset in system (600) is configured such that the planet carrier (32) is the braked element rather than the ring gear (40). The ring gear (40) is used as the output to the wheel (44). A chain (42) and sprocket (43) connect the ring gear (40) to the rear wheel (44) of the motorcycle of system (600). This is similar to a typical chain-drive motorcycle, but here the chain (