Series hybrid / human powered vehicles and stationary fitness machines

Abstract

A series hybrid / human-powered vehicle includes a generator rotatably coupled to a crankset with foot or hand pedals, one or more motors electrically coupled to the generator and mechanically coupled to vehicle wheels, and a user input resistance device providing supplemental counter-torque to the crankset. A controller with a processor and memory executes instructions to: determine an optimal range of pedaling cadence and torque for a user, calculate a generator counter-torque at the optimal cadence, and set the user input resistance device to adjust the overall counter-torque, which comprises generator and supplemental counter-torques, to maintain it within the optimal range. A stationary fitness machine may incorporate similar components to enhance exercise performance.

Description

SERIES HYBRID / HUMAN POWERED VEHICLES AND STATIONARY FITNESSMACHINESTechnical Field

[0001] The present disclosure relates to vehicles and fitness machines operated by human effort and electric assistance, and more specifically, to series hybrid systems for human-powered vehicles and stationary fitness machines for improved pedaling experience.Background

[0002] Human power can be effectively used for personal propulsion using purely mechanical means, or it can be supplemented with electrical energy from on-board sources such as a battery, capacitor or solar panel. Applications may include lightweight land, sea and air vehicles, where human power can provide a significant proportion of the required propulsion power to usefully increase vehicle range and efficiency.

[0003] The most common method of harvesting human energy is through pedaled cranks which convert linear leg forces into rotational torque, connected to an electric machine either directly or through gearing. Higher efficiency can be reached by adding arm power, but this may be rare due to its mechanical complexity. Pedaling also benefits from the success of the bicycle which almost every person has experience of operating.

[0004] The bicycle may be the most common application of hybrid human-powered vehicles and will be used as the main non-limiting example in the following description, but the same concept may apply to any vehicle that captures human energy through pedaling or a similar arrangement.

[0005] When human power is combined with electrical power, two arrangements can be typically used: i) a parallel-hybrid system, where both mechanical and electric drives are used to propel the vehicle side-by-side; and ii) a series-hybrid system, where only the electric drive can propel the vehicle and human power is converted into electrical energy before it is supplied to the electric drive.

[0006] Series-hybrid systems may provide several benefits over parallel-hybrid systems, including: elimination of mechanical transmission losses; greater flexibility of vehicle design and layout; reduced wear and maintenance; lower mechanical complexity and cost; and ease of operation at a comfortable speed over a range of vehicle speeds without gearing.

[0007] On the other hand for bicycle applications, parallel-hybrid systems have become near universal for two main advantages: a higher transmission efficiency due to lower conversion losses; and a more intuitive operation due to the similarity in feeling and response to that of a purely mechanical drive.Summary

[0008] In one aspect, the present disclosure provides a series hybrid / human powered vehicle comprising: a generator; a crankset rotatably coupled to the generator, the crankset comprising a foot pedal or hand pedal; one or more motors electrically coupled to the generator and mechanically coupled to one or more wheels of the vehicle; a user input resistance device coupled to the crankset and operable to provide a supplemental counter-torque thereto; and a controller comprising a processor and a memory having encoded thereon instructions executable by the processor to: (a) determine an optimal range of pedaling cadence and torque for a user; (b) determine a generator counter-torque produced by the generator at the determined optimal pedaling cadence, the generator counter-torque and the supplemental counter-torque constituting an overall counter-torque; and (c) set the user input resistance device so that the overall countertorque is within the optimal range of pedaling torque at the optimal pedaling cadence.

[0009] According to some embodiments, the optimal range of pedaling cadence and torque of the user may be determined from a pedaling torque curve selected by the user or derived from user-specific calibration data.

[0010] According to some embodiments, the user input resistance device may be a bidirectional inverter coupled to the generator.

[0011] According to some embodiments, the controller may be configured to operate the user input resistance device to supply a current through the generator to generate the supplemental counter-torque when a pedaling cadence is below a predefined charging threshold.

[0012] According to some embodiments, the controller may be configured to divert at least a portion of a current generated by the generator to a supplementary energy storage device or a dissipation load, when a pedaling cadence exceeds a predefined regulating threshold and / or the storage device is unable to accept excessive current.

[0013] According to some embodiments, the controller may be configured to maintain the overall counter-torque within the optimal range of pedaling torque at the optimal pedaling cadence when the vehicle is in dynamic equilibrium, wherein dynamic equilibrium represents a state in which the vehicle operates at the optimal pedaling cadence with variations in vehicle load and / or pedaling input remaining below a predetermined equilibrium threshold.

[0014] According to some embodiments, the controller may be further configured to establish a new dynamic equilibrium at an updated optimal pedaling cadence, corresponding to an instantaneous change in vehicle load and / or pedaling input that disrupts the dynamic equilibrium, by adjusting the overall counter-torque.

[0015] According to some embodiments, the overall counter-torque may be maintained by applying a predefined torque profile synchronized with a rotational position of the crankset provided by an angle or position sensor to compensate for human torque ripple during pedaling.

[0016] According to some embodiments, the optimal pedaling cadence may be determined as the cadence at which an output power of the user reaches a predefined maximum value on a userspecific torque-speed curve.

[0017] According to some embodiments, the controller may be configured to perform a calibration process by analyzing a pedaling torque and pedaling cadence of the user, and storing resulting torque-speed data to define a user-specific profile.

[0018] According to some embodiments, the user-specific profile may define relationships among pedaling effort, power, torque, and cadence associated with the user.

[0019] According to some embodiments, the controller may be configured to update the user-specific profile dynamically based on physiological data collected from a physiological sensor monitoring the user during operation.

[0020] According to some embodiments, the physiological data may comprise at least one of heart rate, breathing rate, blood oxygen level, lactic acid level, muscle electromyography data; pedal force / torque , body position, body temperature and facial expression.

[0021] According to some embodiments, the controller may be configured to operate the user input resistance device to apply resistance at a starting crank angle to simulate mechanical inertia when the user starts the vehicle from a substantially stationary state or accelerates pedals to signal a desired vehicle acceleration.

[0022] According to some embodiments, the one or more motors may be capable of being disconnected or unpowered such that the vehicle is used as a stationary fitness machine.

[0023] In another aspect, the present disclosure provides a stationary fitness machine comprising: a generator; a crankset rotatably coupled to the generator, the crankset comprising a foot pedal or hand pedal; a user input resistance device coupled to the crankset and operable to provide a supplemental counter-torque thereto; and a controller comprising a processor and a memory having encoded thereon instructions executable by the processor to: (a) determine an optimal range of pedaling cadence and torque for a user; (b) determine a generator countertorque produced by the generator at the determined optimal pedaling cadence, the generator counter-torque and the supplemental counter-torque constituting an overall counter-torque; and (c) set the user input resistance device so that the overall counter-torque is within the optimal range of pedaling torque at the optimal pedaling cadence.

[0024] According to some embodiments, the optimal range of pedaling cadence and torque of the user may be determined from a pedaling torque curve selected by the user or derived from user-specific calibration data.

[0025] According to some embodiments, the user input resistance device may be a bidirectional inverter coupled to the generator.

[0026] According to some embodiments, the controller may be configured to operate the user input resistance device to supply a current through the generator to generate the supplemental counter-torque when a pedaling cadence is below a predefined charging threshold.

[0027] According to some embodiments, the controller may be configured to divert at least a portion of a current generated by the generator to a supplementary energy storage device or dissipation load when pedaling cadence exceeds a predefined regulating threshold and / or the storage device is unable to accept excessive current.

[0028] There is provided a system described herein that may overcome both limitations of series-hybrid drive systems for human powered applications, while retaining its advantages. In particular, there is provided, and it is an object to provide, an improved generator control system for human-powered vehicles, as well as human-powered vehicles comprising the same and various methods related thereto, disclosed herein.

[0029] There is accordingly provided a method of generating power for a human-powered vehicle according to one aspect. The method includes determining via a control system whether the vehicle is in dynamic equilibrium within a predetermined threshold. If so, the method includes adjusting an average target counter-torque of a generator of the vehicle to promote a constant pedaling speed which maximizes human power output and / or vehicle range.

[0030] There is also provided a method generating power for a human-powered vehicle according to another aspect. The method includes determining an instantaneous effort level of the user via a control system by assessing instantaneous pedal inputs of the vehicle. The method includes matching the instantaneous effort level to an instantaneous torque / speed curve. The method includes adjusting via the control system an average target counter-torque of the generator along the instantaneous torque / speed curve to or towards a pedaling speed which maximizes human power output and / or vehicle range for said instantaneous torque / speed curve.

[0031] There is further provided a method generating power for a human-powered vehicle according to an additional aspect. The method includes determining an instantaneous effort level of the user via a control system by assessing instantaneous pedal inputs of the vehicle so as to estimate / determine / obtain therefrom i) an instantaneous and / or desired torque and / or ii) instantaneous pedaling speed. The method includes matching the instantaneous torque / speed so determined to an instantaneous torque / speed curve. The method includes adjusting via the control system an average target counter-torque of the generator along the instantaneoustorque / speed curve to or towards a pedaling speed which maximizes human power output and / or vehicle range for said instantaneous torque / speed curve.

[0032] There is yet also provided a method of operating a human-powered vehicle according to yet an additional aspect. The method includes determining, estimating and / or acquiring the nature and range of effort contours and torque ripple characteristics of an individual user. The method includes monitoring and updating effort profiles via a control system in response to changes in environment factors, user factors and / or other factors. The method includes facilitating via the control system accurate speed control by responding to vehicle load changes and inputs from the user. The method includes determining via the control system instantaneous counter-torque of a generator of the vehicle and adjusting the same to provide user feedback while promoting / maintaining peak efficiency operation as frequently as possible.

[0033] There is yet further provided a method of generating power for a human-powered vehicle according to another aspect. The method includes assessing pedal inputs in real-time via a control system. The method includes determining via the control system whether a change of vehicle speed is required based on whether a change of pedal inputs exceeds a predetermined threshold and if so, causing vehicle speed to change proportionate to the change of pedal inputs. The method includes determining whether the vehicle is in a dynamic equilibrium within a predetermined threshold and if so, incrementally adjusting via the control system a target average counter-torque of a generator of the vehicle towards a peak human power output.

[0034] There is also provided a control system for a human-powered vehicle configured to operate according to any one of the above methods.

[0035] There is further provided a control system for a human-powered vehicle according to another aspect. The control system is configured to determine whether the vehicle is in dynamic equilibrium within a predetermined threshold and if so, adjusting the counter-torque of the generator to promote a constant pedaling speed which maximizes human power output and / or vehicle range.

[0036] There is additionally provided a control system for a human-powered vehicle according to another aspect. The control system is configured to determine, estimate and / oracquire the nature and range of effort contours and torque ripple characteristics of an individual user. The control system is configured to monitor and update effort profiles in response to changes in environment factors, user factors and / or other factors. The control system is configured to facilitate accurate speed control by responding to vehicle load changes and inputs from the user. The control system is configured to determine instantaneous counter-torque of a generator of the vehicle and adjust the same to provide user feedback while maintaining / promoting peak efficiency operation as frequently as possible.

[0037] There is yet also provided a control system for a human-powered vehicle according to another aspect. The control system is configured to assess instantaneous pedal inputs of the vehicle so as to obtain an instantaneous effort level therefrom. The control system is configured to match the instantaneous effort level to an instantaneous torque / speed curve. The control system is configured to adjust an average target counter-torque of a generator of the vehicle along the instantaneous torque / speed curve to promote or towards a pedaling speed which maximizes human power output and / or vehicle range and / or optimise human exertion to achieve desired fitness goals.

[0038] There is further provided a human-powered vehicle comprising any of the above control systems and / or configured to operate according to any one of the above methods.

[0039] There is also provided human-powered vehicle according to another aspect. The human-powered vehicle includes a generator assembly. The generator assembly includes a pedal mounted on a frame and a generator to which the pedal couples. The generator is configured to convert human power into electrical energy, with rotation of the generator producing a countertorque. The human-powered vehicle includes a control system. The control system is configured to i) assess pedal inputs, ii) adjust vehicle speed and the counter-torque based on thereon, iii) determine whether the vehicle is in dynamic equilibrium within a predetermined threshold and iv) if so, further adjust the counter-torque of the generator to promote a constant pedaling speed which maximizes human power output and / or vehicle range (as above).

[0040] It is emphasized that the invention relates to all combinations of the above features, even if these are recited in different claims.

[0041] Further aspects and example embodiments are illustrated in the accompanying drawings and / or described in the following description.BRIEF DESCRIPTION OF DRAWINGS

[0042] The accompanying drawings illustrate non-limiting example embodiments of the invention.

[0043] Figure l is a schematic side elevation view of a human-powered vehicle in the form of an electric bicycle according to one aspect, the bicycle including pedals, pedal cranks coupled to the pedals, and an electric generator operatively connected to the pedals and pedal cranks;

[0044] Figure 2 is a circuit diagram of an electric drive system and control system thereof;

[0045] Figure 3 is a graph illustrating human torque / power output from pedaling the electric bicycle of Figure 1 as a function of pedaling speed, with torque and power curves shown thereon;

[0046] Figure 4 is a graph illustrating pedal force variation for a single pedal of the electric bicycle of Figure 1 as a function of pedal crank angle over one crank rotation, with an intended tractive force shown thereon in stippled lines;

[0047] Figure 5 is a graph illustrating human torque output from pedaling the electric bicycle of Figure 1 as a function of pedaling speed, with torque curves thereon shown shifting leftwards or rightwards based on rider strengthjourney duration and / or external environmental factors;

[0048] Figure 6 is a graph illustrating voltage / counter-torque produced by the electric generator of the electric bicycle of Figure 1 as a function of rotational speed of the generator and / or pedaling speed;

[0049] Figure 7 is a graph illustrating voltage produced by the electric generator of the electric bicycle of Figure 1 as a function of rotational speed of the generator and / or pedaling speed, with an unregulated back-EMF (electromotive force) profile together with a boosted back- EMF profile and generator topology shown thereon;

[0050] Figure 8 is a graph illustrating human torque output from pedaling the electric bicycle of Figure 1 as a function of pedaling speed, with minimum effort, baseline effort, and maximum effort curves or profiles shown thereon;

[0051] Figure 9 is a graph illustrating pedal torque variation for a single pedal of the electric bicycle of Figure 1 as a function of pedal crank angle over one crank rotation, with the pedal torque being shown modulated to achieve a target average pedal torque;

[0052] Figure 10 is an enlarged side elevation view of the hub, crank arms and pedals of the electric bicycle of Figure 1, with the crank arms and pedals being shown positioned as a function of crank angle; and

[0053] Figure 11 is a flowchart of decision making of the control system of the electric bicycle of Figure 1 according to one aspect, for combining speed control with efficiency optimisation.DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense.

[0055] Referring to the drawings and first to Figure 1, there is shown a human-powered vehicle 20, in this example a mobility vehicle, in this non-limiting embodiment a micromobility vehicle, in this case a vehicle that is also electrically-powered at least in part, in this non-limiting instance an electric two-wheeled and human-powered vehicle, in this non-limiting case an electric bicycle. The vehicle may be referred to as a human- electric hybrid vehicle. The bicycle may be the most common application of hybrid human-powered vehicles and will be used as the main example in the following, but the same concept can apply to any vehicle that is driven by human muscle power and / or which captures human energy, such as in a non-limiting example through pedaling or a similar arrangement.

[0056] Vehicle 20 includes a frame 22 and a seat 24 coupled to the frame and positioned adjacent top 26 and between front 28 and rear 30 thereof. The vehicle in this non-limiting embodiment includes handlebars 32 coupled to the frame and positioned along the top and towards the front thereof.

[0057] Vehicle 20 includes at least one and in this example a pair of spaced-apart wheels 34, in this example a front wheel 34F and a rear wheel 34R each rotatably coupled to frame 22. The wheels are positioned along bottom 27 and adjacent front 28 and rear 30 of the vehicle, respectively. Wheels 34F and 34R include wheel rims 40F and 40R and tires 42F and 42R coupled thereto, respectively. Each wheel includes a wheel hub 44 radially inwardly positioned from the tire and wheel rim thereof, though this is not strictly required (for example a hub motor could be connected to a ring gear forming the rim in another non-limiting embodiment). Each wheel includes an axle 46 about which the wheel rotatably couples. The axles of vehicle 20 operatively connect to frame 22 so as to inhibit rotation thereof.

[0058] The friction braking system includes one or more brake levers 35 pivotally coupled to handlebars 32 in this non-limiting example. Friction braking system 33 includes at least one and in this example a pair of brakes, in this case friction brakes 37F and 37R operatively connected to respective wheels 34F and 34R.

[0059] The vehicle includes a drive system that is electrically powered in part and human or muscle-powered in part, in this example an electric drive system 48 best seen in Figure 2. The drive system includes at least one and in this non-limiting example a pair of motors 50 and 52. The motors are operatively connected to respective ones of wheels 34F and 34F seen in Figure 1. In other embodiments there may be only one motor operatively connected to one of the wheels, for example. Motors 50 and 52 seen in Figure 2 may be referred to as drive motors or electric drive motors.

[0060] As seen in Figure 1, each motor is operatively connected to frame 22 or a fork 22A thereof. Each motor 52 may in this non-limiting embodiment comprise a brushless direct current (DC) motor that positioned within and / or forming at least in part wheel hub 44 of its respective wheel 34R. Each motor in this non-limiting example includes a rotor 56 mechanically connected to its corresponding wheel rim 40. Each motor 50 in this non-limiting example includes a stator58 connected to axle 46 of its corresponding wheel 34R. Each motor may thus be referred to as a wheel hub motor in this non-limiting example. Vehicle 20 (including one or more of motors thereof) may be configured as comprising direct drive using a suitably sized one or more motors. Alternatively, the vehicle may include for each motor thereof a transmission (not shown) operatively coupled to the motor and which may increase torque output to wheel rim 40 while increasing operating speed of the motor.

[0061] As seen in Figure 1, drive system 48 includes an energy storage device 60, which may comprise a battery though this is not strictly required. The system may be much more effective with a storage device (either electrical or mechanical) but may operate with generated- power alone in other non-limiting embodiments. The battery may be a lithium battery; however, this is not strictly required. Energy storage device 60 couples to frame 22, in this example coupling to and extending along a downtube 62 of the frame. However, the latter is not strictly required and the battery may couple to the frame in other manners in other embodiments. Energy storage device 60 is electrically connected to motors 50 and 52 seen in Figure 2 so as to selectively provide power thereto, via motor controllers 51 and 53, though this is not strictly required.

[0062] Referring to Figure 1, drive system 48 in this non-limiting embodiment includes at least one human-operated apparatus / assembly / member configured to convert reciprocating motion from the rider’s limbs (in this non-limiting example legs) into rotational motion. The at least one human-operated apparatus / assembly / member is in the form of a pedaling assembly 63 in this non-limiting example. The pedaling assembly includes a crankset or pedal crank 64 coupled to frame 22 and positioned near bottom 27 and between front 28 and rear 30 thereof. The pedal crank includes an annular member or hub 66 in this example. It should be understood that while a bicycle is shown as an example in Figure 1, the present disclosure is not limited to this type of machine. For instance, a stationary fitness machine may include various components configured as described herein to enhance the physical exercise experience.

[0063] Pedal crank 64 includes in this non-limiting embodiment at least one and in this example a pair of spaced-apart elongate members, in this case crank arms 68 and 70. The crank arms couple to and extend radially outwards from either side of hub 66. Pedaling assembly 63includes at least one and in this example a pair of vehicle pedals, in this non-limiting example pedals 72 and 74. The pedals are shaped to receive respective feet of the rider in this non-limiting example and may thus be referred to as foot pedals. However, this is not strictly required and the pedals may be configured to receive the rider’s hands in other embodiments and may thus be referred to as hand pedals. Pedals 72 and 74 rotatably couple to distal ends 68A and 70A of respective crank arms 68 and 70. Bicycles and motors, batteries, and pedal cranks thereof per se are well known to those skilled in the art and the various general parts and functionings of the bicycle, motors 50 and 52, energy storage device 60 and pedal crank 64 will accordingly not be described in further detail.

[0064] Vehicle 20 includes in this non-limiting embodiment an electric power generating device, in this example generator 76. The generator is mechanically coupled to pedal crank 64 seen in Figure 1, including crank arms 68 and 70, pedals 72 and 74 and a rotatable shaft 66 thereof operatively connected to the crank arms and pedals. Generator 76 is configured to generate electric power from pedaling or muscle-power: in this case rotation of the pedals by the rider. Each motor 50 is electrically and / or operatively connected to the generator. For the latter, generator 76 may be attached to a separate battery or other energy storage device which is in turn connected to a battery or the motor in one non-limiting embodiment.

[0065] Generator 76 is configured to convert pedaling torque output from the rider into electrical current that may be used to supply motors 50 and 52 seen in Figure 2 or charge energy storage device 60, or to power or charge other devices to which it is electrically connected. The generator thus operatively connects to at least one and this example both wheels 34F and 34R of vehicle 20.

[0066] Generator 76 is additionally configured to generate resistive torque or counter-torque which may be configured to be comfortable for the rider to pedal against at any pedal speed required, ensuring that pedal force may be neither too great nor too light that pedals can be operated smoothly and thereby facilitate accurate speed control.

[0067] As seen in Figure 1, vehicle 20 includes a pedal resistance device 77. The pedal resistance device operatively connects to pedals 72 and 74. Pedal resistance device 77 is configured to provide an independent force or pedal resistance to the pedals which may beindependent of the battery voltage of energy storage device 60 and is independent to or modifies the voltage or current output of generator 76. The pedal resistance device is configured to be capable of continual fine adjustments to supplement the change of base load from the generator. Pedal resistance device 77 is sized / configured to create a highest pedaling force required without any generator load. Non-limiting embodiments of pedal resistance devices which may achieve the above functionality may comprise one or more of: a friction pad, a clutch, a hydraulic dissipator, a fan, a magnet, or pulse width modulation (PWM) switchable circuits using electromagnets, eddy currents, inductors, resistors or capacitors, current injection, polarity switching or current recirculation to modify load. Still referring to Figure 1, vehicle 20 may also include a pedal input controller 79 operatively connected to pedals 72 and 74, that in a preferred non-limiting embodiment is an bi-directional inverter that may operate in selective generation or powered modes by supplying current from and to the generator based on the counter-torque and / or pedal speed required.

[0068] The role of generator 76 may thus be fourfold in this non-limiting embodiment: 1) to harvest human energy to extend range; 2) to provide resistive torque for the user to pedal against for precise speed control; 3) to communicate changes in vehicle load or other haptic-like information; and 4) to enable an electrical transmission of power which mechanically disconnects pedal forces from tractive forces, so that they can be controlled by control system 84 of vehicle 20.

[0069] Vehicle 20 includes first and second data acquisition devices configured to measure or obtain an instantaneous speed / acceleration of wheels 34F and 34R of vehicle 20 and emit one or more signals based thereon. The first and second data acquisition devices in this non-limiting example comprise wheel speed measuring devices, in this case a pair of wheel sensors 78F and 78R operatively connected to respective front and rear wheels 34F and 34R. Each wheel sensor is configured to precisely and reliably measure angular speed and acceleration many times per revolution for its respective wheel. Wheel sensors 78F and 78R according to one non-limiting example may comprise hall sensors or rotary encoders.

[0070] As seen in Figure 2, vehicle 20 may include one or more data acquisition devices to obtain or measure instantaneous slope, angle and / or pitch of the vehicle relative to the horizontaland / or obtain data indicative of instantaneous slope resistance of the vehicle and emit one or more signals based thereon. Slope, angle and / or pitch of vehicle 20 is measured / obtained via a second data acquisition device in the form of an inertial measurement unit (IMU) 80 in this nonlimiting embodiment. However, the latter is not strictly required and other types of devices or sensors may be used in other embodiments to obtain instantaneous slope / angle / pitch / roll- orientation of vehicle 20 including but not limited to one or more of: a microelectromechanical system (MEMS) gyroscope; one or more software inputs such as map topography data and / or GPS mapping / route data; or, inferred from vehicle sensors such as motor current and speed in further non-limiting embodiments.

[0071] Still referring to Figure 2, vehicle 20 in this non-limiting embodiment includes a display 83. The display may include a user interface and operatively connects to handlebars 32 in this non-limiting example. Alternatively or additionally, the user interface may be a program loaded to a secondary device such as a phone, computer, television or headset in further nonlimiting examples.

[0072] Referring to Figures 1 and 2, vehicle 20 includes a control system 84. As seen in Figure 2, the control system includes a processor, in this non-limiting example in the form of and / or a part of a microcontroller 85. Pedal input controller 79 and motor controllers 51 and 53 may be said to be a part of the control system. Referring to Figures 1 and 2, control system 84 (and / or microcontroller 85 thereof) operatively connects to friction braking system 33, motors 50 and 52, motor controllers 51 and 53, pedals 72 and 74, generator 76, pedal resistance device 77, sensors 78F and 78R, IMU 80 and display 83. In addition or alternatively, control system 84 may be said to comprise one or more electric drive motors 50 and 52, connected to frame 22 or fork 22A and coupled to respective one or more wheels 34F and 34R, in turn coupled to respective one or more tires 42F and 42R, such that motor torque can be transmitted to road surface 54 and tractive force produced.

[0073] Referring to Figure 2, processor 85 is configured to receive / respond to user inputs and also determine the amount of acceleration or deceleration required in each situation based on but not limited to speed, steering angle, inclination and pedal inputs, and a plurality of data acquisition devices, such as sensors 39, 78F and 78R, steering angle data acquisition device orsensor 119 and IMU 80 seen in Figure 2 including but not limited to speed, angle, direction, force or acceleration, or any combination of the same. Control system 84 is configured to receive additional inputs from but not limited to user inputs from handlebar 32 seen in Figure 1 mounted switches, dials, levers, proportional hall sensors, proximity sensors, touchscreens, or momentary buttons. Referring back to Figure 2, processor 85 may function independently based on environmental sensors used to detect obstacles, road surface condition, visibility, moisture, temperature, tire pressure, traffic signs or lights, global positioning system(s) (GPS), traffic mapping, vehi cl e-to- vehicle and / or infrastructure-to-vehicle communication.

[0074] Further details of a non-limiting embodiment of a haptic-like human-powered vehicle, an electric drive system thereof and a method of providing pedal resistance thereto, as well as other human-powered vehicles and features thereof, may be found in i) United States Provisional Patent Application No. 63 / 593499 filed in the United States Patent and Trademark Office on 26 October 2023, ii) United States Provisional Patent Application No. 63 / 619012 filed in the United States Patent and Trademark Office on 9 January 2024, and iii) United States Provisional Patent Application No. 63 / 502838 filed in the United States Patent and Trademark Office on 17 May 2023, the disclosures of which are each incorporated herein by reference.

[0075] Control system 84 is configured to function at least in part and may thus be referred to as a generator control system. For efficient use as a propulsion system, a primary object of a generating system of a series-hybrid human / electric drive is to capture as much human energy as possible so that it can be stored for later use, or supplied directly to the electric drive. Lost energy lowers vehicle range and increases the size of storage devices needed, adding unwanted cost and weight.

[0076] Referring to Figure 1, by turning pedal cranks 64 (or pedal arms 68 and 70 thereof) which are mechanically connected to an electric machine or other conversion device such as generator 76, counter electromotive force (back-EMF) can be generated in proportion to the speed of pedaling, at a rate determined by voltage characteristics of the electric machine. If sufficiently high, current may be generated that is proportional to the torque input and torque characteristics of the machine.

[0077] In this way energy can be captured effectively across a range of speeds, with the counter-torque felt by the human dependent on the voltage and current generated, as well as the combined electrical load that is provided by the battery pack and / or additional energy storage devices, and / or dissipation load.

[0078] Control system 84 as herein described includes voltage boosting and regulation 131 to provide generating current across a range of pedaling speeds. Since direct-current (DC) storage devices are most common, electric drives are typically powered by DC voltage. It is therefore only possible to store or use energy if the voltage produced by the generator is greater than the bus voltage of the electric drive. If not, current will not flow from the generator and will instead be circulated and wasted as heat. Microcontroller 85 seen in Figure 2 is configured to adjust the amount of voltage boosting needed at different rotational speeds using feedback from a speed sensor, such as wheel sensors 78F and 78R seen in Figure 1. At lower speeds more boosting is required, while at rated speeds voltage boosting may be removed. If voltage is too high for the storage device it may be stepped down by converter 132 or disconnected. When the storage device cannot accept excessive current, it may be diverted at least in part to a resistive load to dissipate energy as heat, or stored in a supplementary storage device as kinetic, electrical or chemical energy that is configured to be operable at lower speeds.

[0079] For human-power generation there may be two objectives. A first objective may be to limit the amount of generator counter-torque so that the human can always turn the pedals to regulate speed and / or continue generating when possible. To achieve this functionality, current can be proportionally diverted to a smaller electrical load to regulate the counter-torque at the expense of lower efficiency in one non-limiting embodiment, or modulated at a variable duty cycle between loaded and unloaded conditions using PWM switching in a further non-limiting embodiment.

[0080] A second objective for human-power generation may be to ensure that counter-torque is not too low or else the human may not be able to control pedaling speed easily. Counter-torque which is too low may result in biomechanical efficiency due to excessive and / or irregular rotational speed. It is also known that some dynamic control of counter-torque is important to provide the user with the familiar feel of a mechanical drive system and thereby facilitateaccurate control of rotational speed that may in turn be used to a desired vehicle speed or acceleration. This may include, but is not limited to, higher counter-torque when starting or accelerating to simulate the inertia effect of vehicle weight. Various solutions to increase counter-torque are known and will not be elaborated upon here. Controlling the flow of current proportionally through various circuits, the counter-torque experienced by the user may be increased and decreased by a microcontroller and may be independent of current drawn by the electric drive or the state of the storage device. Further details of non-limiting systems in this regard are disclosed, for example in United States Provisional Patent Application No. 63 / 593499 filed in the United States Patent and Trademark Office on 26 October 2023, and the disclosure of which is incorporated herein by reference and priority to which is claimed.Problems to be solved

[0081] Implementing pedal generation with dynamic counter-torque control may be straightforward as described and a necessary starting point, but to feel comfortable, intuitive and useful as a human-powered vehicle, several resulting problems may additionally need to be overcome. Furthermore, it may be possible to increase vehicle range by optimizing the energy usage of the user to provide parity and potential superiority over parallel-hybrid systems. In the following, these challenges are outlined and grouped into three areas for clarity.Vehicle speed control

[0082] It is known from sports science that humans may have a window of pedaling speed and torque at which they can produce optimal power output. It therefore may be most biomechanically efficient for humans to operate at a speed and torque where highest power is produced for a given effort. As shown in Figure 3, torque output generally falls with speed as shown by torque curve 86, from a maximum or peak torque TMAX when vehicle 20 seen in Figure 1 is stationary, to a maximum pedaling speed COMAX of the vehicle seen in Figure 3 where no or zero torque To may be produced. This creates an inverted U-shaped power curve 88 and an inflection point 90 that defines an optimum torque / speed combination at which the user is producing peak power PMAX. The torque curve as herein described may be referred to as a torque profile and vice versa. The torque curve may also be referred to as torque / speed curve.

[0083] Power may be limited by muscle strength at lower pedaling speeds and may be limited by biomechanical inefficiency at higher speeds. Each point on torque curve 86 may feel equally “difficult”, but only at the pedaling speed of optical efficiency co* is energy conversion maximized and the greatest amount of bodily stored energy converted into useful mechanical work. This may be both ideal for human health and fitness, while also reducing the electrical energy consumed by vehicle 20 seen in Figure 1 and extending the range of the vehicle. Advantageously for a series-hybrid system, there is no need to link human pedaling speed with vehicle speed mechanically through gearing, so an optimum speed can be maintained by adjusting counter-torque automatically and therefore the opposing human torque, T applied to the pedal cranks.

[0084] However, as a means of vehicle propulsion, pedaling speed may remain a convenient and intuitive way to control vehicle speed and one which contributes to a more interactive and pleasurable experience. On the other hand, human-power generation may be greatly complicated if pedals are used to govern vehicle speed, as constant pedal speed / counter-torque may no longer be targeted arbitrarily.

[0085] For example, users may be accustomed to using pedaling speed / force to make adjustments in speed, acceleration, steering trajectory and momentum, particularly as it relates to experience gained from a conventional bicycle. Around comers for example, pedaling may be slowed to maintain stability, and the vehicle is allowed coast until the exit is reached and the user wishes to accelerate. In a second example, pedaling speed may be quickened to build momentum prior to a steep hill. Likewise, in a series-hybrid system the vehicle may need to respond to these subtle cues accordingly, while providing the user with an expected counter-torque for that situation.

[0086] Therefore, an ideal generating system may need to allow the user to access a wide range of pedaling speeds to provide control of vehicle speed on the one hand, while converting as much human power into electrical power as possible on the other hand.Pedal torque ripple

[0087] A further complication is provided by significant amounts of torque ripple that may be generated by cyclic variations in the force applied by linear leg muscles acting on a rotatable shaft 66 seen in Figure 1. Referring to Figure 4, this may result in the ability to generate maximum torque over only a small range of crank angles a, while zero torque may be generated at other angles.

[0088] For example, applied leg or pedal force may be much higher at a crank angle of approximately 90 degrees from the highest or top dead center position of pedals 72 and 74 seen in Figure 1, as shown by maximum pedal force FPMAXI in Figure 4 in the downward direction. The pedal force may thereafter lower to zero as the pedal rotates close to its lowest position, as shown by minimum pedal force FPMIN generally corresponding to a crank angle in this nonlimiting example of 150-160 degrees from top dead center. A second pedal force peak may occur in the upward direction as shown by maximum pedal force FPMAX2 generally corresponding to a crank angle in this non-limiting example of 240-250 degrees from top dead center. It may be possible to somewhat smooth this pedal force versus crank angle curve i) when feet are firmly coupled to pedals 72 and 74 seen in Figure 1 via clips and ii) with considerable skill; however, such a reduction of the torque tipple may remain imperfect.

[0089] Referring back to Figure 4, peak forces FPMAXI and FPMAX2 may occur at approximately every half rotation of the pedals when left and right pedal forces are combined. Referring to Figure 1, when using generator 76 torque applied may thus vary from its maximum value to zero over approximately every half rotation of pedals 72 and 74. Conversely when a constant counter-torque is provided by the generator, the user may perceive uneven resistance as the moment provided by their leg force naturally increases and decreases as the pedal is positioned fore and aft the center of rotation, and this may become more pronounced as torque and / or speed increases. The result may be an uncomfortable amount of variation in rotational speed as applied pedaling torque exceeds resistive counter-torque and vice versa. Furthermore, error may thus be introduced to vehicle speed control algorithms that may be based on pedal speed or force at a resolution below that of one pedal revolution.Human physiology optimisation

[0090] A yet further complication may be that the physiology of each person may be quite different and result in differences in both maximum pedaling power and / or torque output as well as the range of feasible torque and speed combinations that can be maintained for short and long periods. In addition, the amount of muscle effort, heat loss and heart rate that can be tolerated may also vary markedly from person to person and at different times. Referring to Figure 2, control system 84 configured to produce a certain counter-torque for a given effort level may need to be different for each user, since it may be the relative perceived level of effort that is important to the user and not the absolute counter-torque experienced.

[0091] Now referring to Figure 5 and as has been described previously, human torque is generally downward sloping with respect to increasing pedaling speed as shown by torque curve 92, which may represent a median or average rider and / or journey duration. The highest torque TBMAX may be produced statically or at a pedal rotational speed of zero, and as pedaling speed is increased, the amount of torque that can be produced by the user naturally diminishes. Torque TBMAX may be referred to as an average, median or baseline peak torque. This underlying relationship may be somewhat consistent but encompasses a series of torque / speed curves that may be shifted rightwards (as seen by arrow 96) and leftwards (as seen by arrow 94) based on several variables.

[0092] Rightward torque curve 98 may correspond to a rider who is able to output a maximum or peak torque THMAX when pedals are stationary which is higher than the median peak torque TBMAX seen in Figure 5. Leftward torque curve 100 corresponds to a rider who is able to output a maximum or peak torque TLMAX when pedals are stationary which is lower than the median peak torque. These curves may correspond to an array of points forming a contour, that describe what a given rider may comfortably be able to output in one non-limiting embodiment.

[0093] These profiles (and shifts thereof) may vary: across riders; within an individual rider; over the duration of a journey; and / or over time. For example, a stronger rider, who may be more athletic and / or physiologically stronger than average, may generally be able to output a relatively higher torque as shown by torque curve 98. In contrast, a weaker rider, who may be less athletic and / or physiologically weaker than average, may generally be able to output a relatively lowertorque as shown by torque curve 100. As has been described herein, an unsuitable counter-torque for a particular user may be uncomfortable, inefficient and result in speed control errors or unintended signals to a control system which may be determining vehicle speed.

[0094] Similarly, rightward torque curves 98 may generally be tolerable for short durations regardless of the fitness level or physiological characteristics of the rider, while muscle fatigue may generally cause a shift towards leftward torque curves 100. The latter may likewise occur regardless of the rider’s fitness level or physiological characteristics where, for example, a stronger rider is on a particularly difficult and / or longer journey. External factors, in this nonlimiting example external environmental factors such as ambient temperature, air pressure, humidity and wind speed, may additionally alter the rider’s rate of heat loss and further shift the torque curve’s position leftwards 94 and / or rightwards 96 in other non-limiting examples.

[0095] Each torque curve 92, 98 and 100 shown in Figure 5 may be considered an “effort contour”, whereby each point on the curve feels equally difficult for the rider, even though they result in quite different amounts of power being produced. Generator 76 seen in Figure 2 to produce a perception of consistent effort, is configured to adjust counter-torque proportional to rotational speed to maintain a position on the same effort contour. Increased or reduced effort are achieved by moving to a new effort contour at an appropriate position.

[0096] Unfortunately, and now referring to Figure 6, the counter-torque produced by the generator may increase proportionally with rotational pedal speed since back-EMF is determined by the machine's voltage constant. This is seen by upward sloping counter-torque curve 102 as a function of increasing rotational speed of the generator and / or pedaling speed. Although the gradient can be increased by mechanical gearing or voltage boosting, the back-EMF at low speeds may be insufficient to drive current from the generator and therefore less counter-torque is produced.

[0097] Thus, in addition to generating with some degree of counter-torque control, an ideal generating system should also: determine the nature and range of effort contours and torque ripple characteristics of individual riders;monitor and update effort profiles in response to changes in environment, user or other factors;• facilitate accurate speed control by responding to vehicle load changes and inputs from the user; and• determine instantaneous counter-torque and adjust to provide user feedback while maintaining peak efficiency operation as frequently as possible.

[0098] The system’s effectiveness in providing these features may determine how intuitive the vehicle is to operate for a range of users and situations, as well as the performance and efficiency of the series-hybrid drive system.Solution and control system concept

[0099] Referring to Figures 1 and 2, control system 84 as herein described may provide a solution comprising four parts:1) counter-torque control;2) user profile calibration;3) torque ripple compensation; and4) efficiency optimization.Counter-torque control

[0100] As described herein, the back-EMF of generator 76 seen in Figure 2 can be used to produce counter-torque, but this may not be sufficient due to an upward-sloped counter-torque curve seen in Figure 6 that opposes the downward-sloped torque curve 92 / 98 / 100 of the user seen in Figure 5, with respect to pedaling speed.

[0101] Now referring to Figure 7, voltage boosting using known methods may function to i) steepen the back-EMF profile 104 compared to unregulated back-EMF 102 and ii) widen the speed range over which current can be supplied to the rest of the system and thus counter-torque provided, at the expense of increased losses.

[0102] However, below the minimum charging speed COMIN, back-EMF remains too low to create counter-torque. To allow control system 84 seen in Figure 2 to be effective over the full torque range, electrical energy within generator 76 must be recirculated or supplemented with stored energy to increase magnetic forces and retard the machine artificially. Several “braking” methods are known and therefore will not be elaborated here. In each case, human energy may be wasted to reduce efficiency, yet this region may be essential due to the high counter-torque needed to oppose the downward sloping human torque curve 92 / 98 / 100 seen in Figure 5, particularly at lower pedaling speeds. The proportion of time spent in this region may be relatively small, but is encountered frequently as pedaling speeds naturally increase and decrease in response to changing conditions and required accelerations or decelerations that require continual transitions in and out of the “braking” region.

[0103] In a non-limiting embodiment, the braking region may be accomplished by a bidirectional inverter (as an example of the user input resistance device). Advantageously, a bidirectional inverter may be used to both rectify alternating current from the generator, while also being capable of inverting direct current supplied to the generator to produce counter-torque by transitioning from positive to negative current flow and vice versa. Utilising the constant torque characteristic of an electrical machine, maximum torque may therefore be produced by the generator from zero pedaling speed upwards. Given the torque constant of an electrical machine, counter-torque may be accurately governed from the phase current supplied. While configured to never propel pedals backwards, the speed of pedaling and resistance felt by the user may be governed by current control methods in any situation where natural counter-torque produced by directing current from the generator towards a battery or other electrical load is insufficient.

[0104] In scenarios where the vehicle starts from stationary, and in a further non-limiting embodiment, the bi-directional inverter can provide targeted resistance at specific crank angles (referred to as starting crank angles) via positional control. These angles correspond to positions where riders typically apply the greatest moment about the crank axis. For example, Figure 4 shows that a normal rider may apply the maximum torque when the crank angle is about 90 degrees, which typically corresponds to the starting crank angle that the rider would start the vehicle from the stationary state. An angle sensor, such as a rotary encoder or hall sensor in nonlimiting examples, may be used to locate the pedal position and enable precise control of thetorque applied by the inverter at different crank angles. By dynamically adjusting the current supplied and thus counter-torque provided by the electric machine based on sensor input, the inverter can closely mimic the feeling of a traditional chain or belt drive system that corresponds to mechanical inertia. This capability may be particularly beneficial when starting on an incline, where maintaining stability and preventing backward rolling are critical for safety and comfort.

[0105] The bi-directional inverter’s ability to dynamically adjust torque enables seamless transitions between pedaling states, so that the vehicle remains intuitive and easy to operate. This may be advantageous in hybrid systems, where balancing human and motorized inputs facilitates the optimization of user comfort and energy efficiency. The inverter can dynamically modify resistance or torque profiles to closely align with the user’s physiological capabilities and expectations, for example, by referring to the profiles shown in Figure 7. Additionally, the natural increase in resistance with pedaling speed due to the voltage constant can adjusted for by control system 84 and may provide precise control over both pedaling effort and vehicle speed.

[0106] To maximize efficiency, the control system and generator’s topology should therefore be configured so that pedal speeds remain above COMIN at the user's most frequent pedaling speeds, and ideally higher so that boosting losses can be avoided / inhibited.

[0107] Advantageously, control system 84 seen in Figure 2 and as herein described, is configured to directly control the user’s pedaling speed by lowering or raising counter-torque progressively until a new dynamic equilibrium is reached. This may be analogous to shifting to a lower gear that increases pedaling speed and lowers torque required.

[0108] In this way the efficiency of the system can be optimized by reducing time spent in the inefficient braking region 106 and instead, moving the user along their torque / speed curve 92 / 98 / 100 seen in Figure 5 to a point where back-EMF is increased and generating can resume.User profile calibration

[0109] To establish the relationship between effort, power, torque and speed, a range of torque curves can be defined that are unique to a particular user and can be used as the basis for speed control and further optimisation.

[0110] Referring to Figure 8, this may consist of at least three torque / speed curves. Firstly, a nominal profile 108 which is the preferred range of speed and torque values that the user can maintain for long periods. This may be referred to or considered as a baseline effort or torque output of the user. Secondly, a maximum profile 110 that the user can only tolerate for a short period, such as 5 to 10 seconds in one non-limiting example. This may be referred to or considered as a maximum effort or torque output of the user. Finally, a lowest profile 112 that the user may tolerate and below which resistance is insufficient to control pedaling speed comfortably. This may be referred to or considered as a minimum effort or torque output of the user. Between these two limits are a range of effort levels which can be used to provide feedback to the rider to aid speed and acceleration control or to provide user choice. In this way, a complete map of feasible combinations can be created that are tuned to the physiology and preferences of individual users.

[0111] In one non-limiting example, vehicle 20 seen in Figure 1 encounters a steep hill and speed is reduced as a result thereof. Vehicle load is therefore increased, and more counter-torque is requested. To achieve this, a rightward profile 110 may be selected that cannot be sustained for a long period. If the user wishes to tolerate a higher effort for a period of time, more power is requested and a higher speed is achieved. If the user does not wish to tolerate a higher effort, then the user may return to their preferred profile and lower vehicle speed.

[0112] To create these curves, several methods are possible which could be used in combination to improve performance over time.

[0113] In the first method, no input is required from the user and instead curves are estimated based on previously gathered data from different groups of users and conveyed to and / or stored within control system 84 seen in Figure 2. Non-limiting examples of input data may include height, weight, age, gender, body composition, blood pressure, resting heart rate, maximum heart rate, VO2 max, lactate threshold, images / videos or other data that could be used to match individuals to the closest data set available. Data could also be imported from exercise equipment, previous product data, or using a physiology or fitness questionnaire in other nonlimiting examples.

[0114] In a second method, control system 84 is configured to conduct a predefined calibration sequence that may be conducted while vehicle 20 is stationary. The user may be asked to pedal at a set speed by the control system and may be provided feedback via display 83 seen in Figure 1 in one non-limiting example. Control system 84 in this non-limiting example is configured to next perform a torque sweep, that is to cause the user to pedal through an output range of zero torque output through to a maximum torque output and record the torque output at which speed falls or increases for the given user. The control system may be configured to use this data to define points on the upper and lower curves or profiles 110 and 112 seen in Figure 8 while also defining points on the preferred torque / speed curve or profile 108. Control system 84 may be configured to repeat this process at various speeds and / or using interpolation, so as to obtain a full map or range of effort levels / profiles or torque curves tailored / specific to the given user.

[0115] In a third method, control system 84 seen in Figure 2 may use regression analysis of a cloud of speed / torque data points taken from each journey. Mean trend lines may indicate the preferred profile 108 seen in Figure 8, while persistent higher speeds may indicate that effort curves must be shifted rightward or vice versa. Machine learning may be used to enable control system 84 to actuate / initiate these adjustments automatically and to analyze the response to changes in real time. Alternatively, or additionally, the control system may be configured to suggest to the user (such as via display 83 seen in Figure 1) that effort profiles may need adjustment and prompt the user to confirm or reject the request / suggest! on, with the control system actuating or refraining to actuate said adjustment in response to said user feedback / input. Alternatively, or additionally, the user may indicate higher or lower effort via switches, buttons dials, levers or touchscreen attached to handlebar 32 in some non-limiting examples, such that the system 84 may learn and update the preferred effort profiles of the user.

[0116] In a fourth method, control system 84 is configured to receive, use and / or acquire user data, such as non-limited examples heart rate, breathing rate, blood oxygen or lactic acid level, muscle electromyography, pedal pressure, crank stress or strain, crank axle torque or current generation, and crank axle speed or voltage as additional feedback in determining effort profiles and / or initiating and / or suggesting adjustments thereto. This may comprise user data measured / acquired in real-time via one or more sensors and / or third-party devices operativelyconnected to and / or in communication with control system 84. In addition or alternatively, control system 84 may be configured to receive and / or take into account input fitness goals that raise effort level over time and / or to meet a specific training regimen. In addition or alternatively, the control system may be configured to take into account health data and / or medical prescription information, with the control system being configured to inhibit / limit effort levels in response thereto to reduce the risk of injury and / or other negative health outcomes, and / or optimise effort levels to efficiently facilitate improved health, strength and fitness, in some non-limiting examples.

[0117] In practice, controls system 84 may be configured to incorporate each of these methods in sequence or selectively to provide an experience that may improve over time and dynamically respond to user changes or preferences.Torque ripple compensation

[0118] To avoid or reduce the feeling of uneven pedal force due to cyclic variation in muscle strength described above, control system 84 is configured to modulate the counter-torque target over one cycle to achieve the target as an average or peak value, as shown by target average pedal torque TPAV in Figure 9. Assuming no gearing is used and over one complete rotation, the control system is configured to cycle the counter-torque twice from a minimum value or torque TPMIN (e.g. zero), to a maximum value or torque TPMAX, to coincide with pedal force from one leg and then the other at a 180-degree phase shift.

[0119] A wide range of compensation waveforms or profiles are possible and can be controlled by microcontroller 85 seen in Figure 2 and overlaid on top of an underlying user profile to create a feeling of constant load through each pedal revolution. Referring to Figure 10, absolute crank angle a may be determined using suitable angle measurement (e.g. via a sensor 114 configured to measure the respective angles of crank arms 68 and 70 in real-time and which is operatively connected to control system 84 seen in Figure 2) so that the control system can cause counter-torque to be increased and reduced in synchronicity with increasing and reducing pedal force.

[0120] Different waveforms or profiles may feel more or less smooth or responsive to each user. In one non-limiting example shown in Figure 9, a trapezoidal waveform is used as a function of and based on crank angle a so measured / determined. Alternatively or additionally, pedal speed targeting may be used so that counter-torque is automatically increased to slow pedal speed, or reduced to increase pedal speed cyclically in a non-limiting embodiment.

[0121] The final form of the compensation curve may be preconfigured, calibrated or developed from regression and machine learning algorithms while in use. Some user configuration may also be possible to further tune the shape and amplitude to specific tastes. In this way, compensation may be optimized for different user physiologies and / or preferences and improved over time.Efficiency optimisation

[0122] In general and referring to Figure 1, when vehicle 20 is in dynamic equilibrium (i.e. when there is little or no change in vehicle load and little or no change in user input is requested), control system 84 in one non-limiting embodiment is configured to target a constant pedaling speed that achieves the highest human power and maximum vehicle range.

[0123] For a mechanical system, this may be achieved through trial-and-error selection of different gear ratios. Advantageously for control system 84 described herein, this optimisation may be conducted automatically using the control system’s knowledge of the user’s power curve and control of the operating speed by altering counter-torque dynamically.

[0124] From this starting point, the user may wish to break equilibrium by changing their pedaling input, to indicate a change in vehicle speed is needed and at a rate that may be proportional to the change pedal speed, acceleration, force or torque of any combination in some non-limiting examples. Since the target counter-torque may be connected to vehicle load, a new equilibrium may thus be reached at a different speed. In this way, speed control can be combined with efficiency optimisation to ensure the greatest possible range, while remaining responsive to user inputs.

[0125] A non-limiting example of the decision process of control system 84 of vehicle 20 is shown in Figure 11. The control system is configured to first assess pedal inputs in real-time asshown by box 116. Control system 84 is next configured to determine whether a change in vehicle speed as shown by box 118. This may involve determining whether an instantaneous pedal input (e.g. speed, acceleration and / or force thereof) is different from a prior or previous pedal input past a predetermined threshold. If no and as shown by arrow 120, control system 84 takes no action and assesses pedal inputs anew.

[0126] If the control system determines that a change of vehicle speed is required based on the assessment of the pedal inputs, the control system is configured as seen by box 122 to cause vehicle speed to be updated (e.g. via actuating / adjustment of motor(s) 50 and 52 seen in Figure 2) in proportion to the pedal speed, acceleration and / or force.

[0127] A new equilibrium may thus be reached at a different speed and control system 84 is configured to update the counter-torque target as shown by box 124, as the target counter-torque may be connected to vehicle load. The control system may be configured to next determine whether a given user is operating at peak power within a predetermined threshold as shown by box 126, based on one or more of the above methods for example. If no, control system 84 is configured to adjust counter-torque as shown by box 128, and then determine whether a given user is operating at peak power anew. If the control system determines that the given user is operating at peak power within a predetermined threshold as shown by arrow 130, then the control system is configured to assess pedal inputs as shown by box 116 anew and the process may be repeated.

[0128] Many advantages result from the structure of the present invention. It will also be appreciated that many variations are possible within the scope of the invention described herein.

[0129] Where a component (e.g. a software module, processor, assembly, device, circuit, etc.) is referred to herein, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e., that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.

[0130] Embodiments of the invention may be implemented using specifically designed hardware, configurable hardware, programmable data processors configured by the provision of software (which may optionally comprise “firmware”) capable of executing on the data processors, special purpose computers or data processors that are specifically programmed, configured, or constructed to perform one or more steps in a method as explained in detail herein and / or combinations of two or more of these. Examples of specifically designed hardware are: logic circuits, application-specific integrated circuits (“ASICs”), large scale integrated circuits (“LSIs”), very large scale integrated circuits (“VLSIs”), and the like. Examples of configurable hardware are: one or more programmable logic devices such as programmable array logic (“PALs”), programmable logic arrays (“PLAs”), and field programmable gate arrays (“FPGAs”). Examples of programmable data processors are: microprocessors, digital signal processors (“DSPs”), embedded processors, graphics processors, math co-processors, general purpose computers, server computers, cloud computers, mainframe computers, computer workstations, and the like. For example, one or more data processors in a control circuit for a device may implement methods as described herein by executing software instructions in a program memory accessible to the processors.

[0131] Processing may be centralized or distributed. Where processing is distributed, information including software and / or data may be kept centrally or distributed. Such information may be exchanged between different functional units by way of a communications network, such as a Local Area Network (LAN), Wide Area Network (WAN), or the Internet, wired or wireless data links, electromagnetic signals, or other data communication channel.

[0132] The invention may also be provided in the form of a program product. The program product may comprise any non-transitory medium which carries a set of computer-readable instructions which, when executed by a data processor, cause the data processor to execute a method of the invention. Program products according to the invention may be in any of a wide variety of forms. The program product may comprise, for example, non-transitory media such as magnetic data storage media including floppy diskettes, hard disk drives, optical data storage media including CD ROMs, DVDs, electronic data storage media including ROMs, flash RAM, EPROMs, hardwired or preprogrammed chips (e.g., EEPROM semiconductor chips),nanotechnology memory, or the like. The computer-readable signals on the program product may optionally be compressed or encrypted.

[0133] In some embodiments, the invention may be implemented in software. For greater clarity, “software” includes any instructions executed on a processor, and may include (but is not limited to) firmware, resident software, microcode, code for configuring a configurable logic circuit, applications, apps, and the like. Both processing hardware and software may be centralized or distributed (or a combination thereof), in whole or in part, as known to those skilled in the art. For example, software and other modules may be accessible via local memory, via a network, via a browser or other application in a distributed computing context, or via other means suitable for the purposes described above.

[0134] Software and other modules may reside on servers, workstations, personal computers, tablet computers, and other devices suitable for the purposes described herein.Interpretation of Terms

[0135] Unless the context clearly requires otherwise, throughout the description and the claims:• “comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”;• “connected”, “coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof;• “herein”, “above”, “below”, and words of similar import, when used to describe this specification, shall refer to this specification as a whole, and not to any particular portions of this specification;“or”, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;• the singular forms “a”, “an”, and “the” also include the meaning of any appropriate plural forms. These terms (“a”, “an”, and “the”) mean one or more unless stated otherwise;• “and / or” is used to indicate one or both stated cases may occur, for example A and / or B includes both (A and B) and (A or B);• “approximately” when applied to a numerical value means the numerical value ± 10%;• where a feature is described as being “optional” or “optionally” present or described as being present “in some embodiments” it is intended that the present disclosure encompasses embodiments where that feature is present and other embodiments where that feature is not necessarily present and other embodiments where that feature is excluded. Further, where any combination of features is described in this application this statement is intended to serve as antecedent basis for the use of exclusive terminology such as "solely," "only" and the like in relation to the combination of features as well as the use of "negative" limitation(s)” to exclude the presence of other features; and• “first” and “second” are used for descriptive purposes and cannot be understood as indicating or implying relative importance or indicating the number of indicated technical features.

[0136] Words that indicate directions such as “vertical”, “transverse”, “horizontal”, “upward”, “downward”, “forward”, “backward”, “inward”, “outward”, “left”, “right”, “front”, “back”, “top”, “bottom”, “below”, “above”, “under”, and the like, used in this description and any accompanying claims (where present), depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.

[0137] Where a range for a value is stated, the stated range includes all sub-ranges of the range. It is intended that the statement of a range supports the value being at an endpoint of the range as well as at any intervening value to the tenth of the unit of the lower limit of the range, as well as any subrange or sets of sub ranges of the range unless the context clearly dictates otherwise or any portion(s) of the stated range is specifically excluded. Where the stated range includes one or both endpoints of the range, ranges excluding either or both of those included endpoints are also included in the invention.

[0138] Certain numerical values described herein are preceded by "about". In this context, "about" provides literal support for the exact numerical value that it precedes, the exact numerical value ±5%, as well as all other numerical values that are near to or approximately equal to that numerical value. Unless otherwise indicated a particular numerical value is included in “about” a specifically recited numerical value where the particular numerical value provides the substantial equivalent of the specifically recited numerical value in the context in which the specifically recited numerical value is presented. For example, a statement that something has the numerical value of “about 10” is to be interpreted as: the set of statements:• in some embodiments the numerical value is 10;• in some embodiments the numerical value is in the range of 9.5 to 10.5; and if from the context the person of ordinary skill in the art would understand that values within a certain range are substantially equivalent to 10 because the values with the range would be understood to provide substantially the same result as the value 10 then “about 10” also includes:• in some embodiments the numerical value is in the range of C to D where C and D are respectively lower and upper endpoints of the range that encompasses all of those values that provide a substantial equivalent to the value 10

[0139] Specific examples of systems, methods and apparatus have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions, and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilledaddressee, including variations obtained by: replacing features, elements and / or acts with equivalent features, elements and / or acts; mixing and matching of features, elements and / or acts from different embodiments; combining features, elements and / or acts from embodiments as described herein with features, elements and / or acts of other technology; and / or omitting combining features, elements and / or acts from described embodiments.

[0140] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any other described embodiment s) without departing from the scope of the present invention.

[0141] Any aspects described above in reference to apparatus may also apply to methods and vice versa.

[0142] Any recited method can be carried out in the order of events recited or in any other order which is logically possible. For example, while processes or blocks are presented in a given order, alternative examples may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and / or modified to provide alternatives or subcombinations. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, simultaneously or at different times.

[0143] Various features are described herein as being present in “some embodiments”. Such features are not mandatory and may not be present in all embodiments. Embodiments of the invention may include zero, any one or any combination of two or more of such features. All possible combinations of such features are contemplated by this disclosure even where such features are shown in different drawings and / or described in different sections or paragraphs. This is limited only to the extent that certain ones of such features are incompatible with other ones of such features in the sense that it would be impossible for a person of ordinary skill in the art to construct a practical embodiment that combines such incompatible features. Consequently, the description that “some embodiments” possess feature A and “some embodiments” possess feature B should be interpreted as an express indication that the inventors also contemplateembodiments which combine features A and B (unless the description states otherwise or features A and B are fundamentally incompatible). This is the case even if features A and B are illustrated in different drawings and / or mentioned in different paragraphs, sections or sentences.

[0144] It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

WHAT IS CLAIMED IS:

1. A series hybrid / human powered vehicle comprising: a generator; a crankset rotatably coupled to the generator, the crankset comprising a foot pedal or hand pedal; one or more motors electrically coupled to the generator and mechanically coupled to one or more wheels of the vehicle; a user input resistance device coupled to the crankset and operable to provide a supplemental counter-torque thereto; and a controller comprising a processor and a memory having encoded thereon instructions executable by the processor to:(a) determine an optimal range of pedaling cadence and torque for a user;(b) determine a generator counter-torque produced by the generator at the determined optimal pedaling cadence, the generator counter-torque and the supplemental counter-torque constituting an overall counter-torque; and(c) set the user input resistance device so that the overall counter-torque is within the optimal range of pedaling torque at the optimal pedaling cadence.

2. The series hybrid / human powered vehicle as claimed in claim 1, wherein the optimal range of pedaling cadence and torque of the user is determined from a pedaling torque curve selected by the user or derived from user-specific calibration data.

3. The series hybrid / human powered vehicle as claimed in claim 1 or 2, wherein the user input resistance device is a bi-directional inverter coupled to the generator.

4. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 3, wherein the controller is configured to operate the user input resistance device to supply acurrent through the generator to generate the supplemental counter-torque when a pedaling cadence is below a predefined charging threshold.

5. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 4, wherein the controller is configured to divert at least a portion of a current generated by the generator to a supplementary energy storage device or dissipation load when pedaling cadence exceeds a predefined regulating threshold or the storage device is unable to accept excessive current.

6. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 5, wherein the controller is configured to maintain the overall counter-torque within the optimal range of pedaling torque at the optimal pedaling cadence when the vehicle is in dynamic equilibrium, wherein dynamic equilibrium represents a state in which the vehicle operates at the optimal pedaling cadence with variations in vehicle load or pedaling input remaining below a predetermined equilibrium threshold.

7. The series hybrid / human-powered vehicle as claimed in claim 6, wherein the controller is further configured to establish a new dynamic equilibrium at an updated optimal pedaling cadence, corresponding to an instantaneous change in vehicle load or pedaling input that disrupts the dynamic equilibrium, by adjusting the overall counter-torque.

8. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 7, wherein the overall counter-torque is maintained by applying a predefined torque profile synchronized with a rotational position of the crankset provided by an angle or position sensor to compensate for human torque ripple during pedaling.

9. The series hybrid / human-powered vehicle as claimed in in any one of claims 1 to 8, wherein the optimal pedaling cadence is determined as the cadence at which an output power of the user reaches a predefined maximum value on a user-specific torque-speed curve.

10. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 9, wherein the controller is configured to perform a calibration process by analyzing a pedaling torque and pedaling cadence of the user, and storing resulting torque-speed data to define a userspecific profile.

11. The series hybrid / human-powered vehicle as claimed in claim 10, wherein the userspecific profile defines relationships among pedaling effort, power, torque, and cadence associated with the user.

12. The series hybrid / human-powered vehicle as claimed in claim 10 or 11, wherein the controller is configured to update the user-specific profile dynamically based on physiological data collected from a physiological sensor monitoring the user during operation.

13. The series hybrid / human-powered vehicle as claimed in claim 12, wherein the physiological data comprises at least one of heart rate, breathing rate, blood oxygen level, lactic acid level, muscle electromyography data, pedal force / torque, body position, body temperature, and facial expression.

14. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 13, wherein the controller is configured to operate the user input resistance device to apply resistance at a starting crank angle to simulate mechanical inertia when the user starts the vehicle from a substantially stationary state or accelerates pedals to signal a desired vehicle acceleration.

15. The series hybrid / human-powered vehicle as claimed in any one of claims 1 to 14, wherein the one or more motors are capable of being disconnected or unpowered such that the vehicle is used as a stationary fitness machine.

16. A stationary fitness machine comprising: a generator; a crankset rotatably coupled to the generator, the crankset comprising a foot pedal or hand pedal; a user input resistance device coupled to the crankset and operable to provide a supplemental counter-torque thereto; and a controller comprising a processor and a memory having encoded thereon instructions executable by the processor to:(a) determine an optimal range of pedaling cadence and torque for a user;(b) determine a generator counter-torque produced by the generator at the determined optimal pedaling cadence, the generator counter-torque and the supplemental counter-torque constituting an overall counter-torque;(c) set the user input resistance device so that the overall counter-torque is within the optimal range of pedaling torque at the optimal pedaling cadence.

17. The stationary fitness machine as claimed in claim 16, wherein the optimal range of pedaling cadence and torque of the user is determined from a pedaling torque curve selected by the user or derived from user-specific calibration data.

18. The stationary fitness machine as claimed in claim 16 or 17, wherein the user input resistance device is a bi-directional inverter coupled to the generator.

19. The stationary fitness machine as claimed in any one of claims 16 to 18, wherein the controller is configured to operate the user input resistance device to supply a current through the generator to generate the supplemental counter-torque when a pedaling cadence is below a predefined charging threshold.

20. The stationary fitness machine as claimed in any one of claims 16 to 19, wherein the controller is configured to divert at least a portion of a current generated by the generator to a supplementary energy storage device or dissipation load when a pedaling cadence exceeds a predefined regulating threshold or the storage device is unable to accept excessive current.