hybrid bicycle and its control system.

Abstract

A hybrid bicycle comprising: a frame, two rear wheels, a crankset, handlebars with control levers, brake levers equipped with a rotation sensor, a control panel, a display, a saddle, a hybrid motor-generator unit consisting of an electric generator and an electric motor, an energy storage battery fixed to the frame, and a controller responsible for energy management, characterized in that: the electric generator is in permanent mechanical connection with the crankset shaft via a succession of sprockets or chains providing an appropriate overdrive ratio; the electric motor is in permanent mechanical connection with one of the wheels; stabilized in a vertical position by a stand, it is usable for physical exercise due to the connection of the crankset to a generator and the absence of a mechanical connection between the crankset and the wheels. Figure for the abbreviation: Fig. 1

Description

Title of the invention: hybrid bicycle and its control method. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a hybrid propulsion bicycle, i.e. both by muscular force and by an electric machine.

[0002] The combination of muscular force and electric driving force allows for a continuously variable and smooth (without jerk) gear reduction, as opposed to the discrete ratio transmission provided by a derailleur sometimes associated with a multi-chainring at the level of the crankset.

[0003] Plug-in hybrid or non-plug-in hybrid powertrains, widely used in automobiles, offer significant fuel savings. This fuel economy results from the efficient management of propulsion by the internal combustion engine, the electric motor, or both simultaneously. Fuel economy essentially corresponds to a reduced demand on the internal combustion engine. Applied to bicycles, this translates to a reduced demand on muscle power, which takes the place of the internal combustion engine. STATE OF THE ART

[0004] In the automotive world, we have hybrid powertrains of different designs. One type, for a so-called 4x2 transmission, is designed as follows: • an electric machine is inserted between the internal combustion engine and the automatic gearbox; • a first clutch is arranged between the internal combustion engine and the electric machine; • a second clutch is interposed between the electric machine and the gearbox; • with the opening of the first clutch we have a purely electric propulsion; • with the opening of the second clutch, it is possible, by using the electric machine as a generator, to recharge the vehicle when it is stopped.

[0005] This design allows the reuse of powertrain components but makes it more complex and bulkier.

[0006] This concept of hybridization does not appear to be applied in the world of cycling.

[0007] A second type of hybridization in the automotive world, significantly simpler, This is achieved using two electric machines: one primarily acting as a motor and the other primarily acting as a generator. A clutch allows for direct connection. from the engine to the wheels via a single, high gear ratio. This allows for greater efficiency on the motorway.

[0008] This concept of hybridization does not appear to be applied in the world of cycling either.

[0009] A third type of hybridization in the automotive world is also achieved using two electric machines in combination with an epicyclic gear train, providing the internal combustion engine with an infinitely variable transmission. A power distribution is established between the first machine, operating as a generator, and the second, operating as a driving machine. The internal combustion engine is permanently connected to the planet carrier of the epicyclic gear train, the generator is permanently connected to the sun gear, and the ring gear sends the resulting power to the wheels and the driving machine.

[0010] This hybridization concept has comparable variations in the bicycle mode, for example in publications WO2010092331A1, BE1022240B1.

[0011] Another type of hybridization in the automotive world, also achieved using two electric machines, pushes simplicity to its extreme. The internal combustion engine drives a generator, and an electric motor drives the vehicle. There is no connection between the two systems. This is, in a way, an electric car that carries a generator. PRESENTATION OF THE INVENTION

[0012] The proposed invention is the application, in the world of bicycles, of this latter type of powertrain.

[0013] The pedal assembly drives an electric machine in the strict role of a generator. The pedal assembly has no mechanical connection with the wheels.

[0014] An electric machine, primarily acting as a drive, is associated with one of the wheels. It can be arranged near the pedal assembly or integrated into the hub of a wheel.

[0015] It has no mechanical connection with the pedal-generator assembly. Being permanently connected to one of the wheels, it can act as an electric brake and thus allows the recovery of kinetic energy.

[0016] Since the crankset is permanently connected to a generator, pedaling is limited to the production of electricity. Having no mechanical link to the wheels, it is therefore conceivable to use it for physical exercise. For this purpose, the bicycle is stabilized on a stand. The pedaling energy is stored in the battery. DETAILED DESCRIPTION OF THE INVENTION

[0017] These features, objectives and advantages of the present invention will become apparent from the detailed description that follows and from the accompanying drawings given by way of non-limiting examples and on which:

[0018] [Fig. 1 is a view of the bicycle, the electric machine is arranged near the pedals.

[0019] [Fig.2] is a view of the handlebar and the functions it carries.

[0020] [Fig.3a] is a view of the bicycle, the electric machine is arranged in the hub of the rear wheel.

[0021] [Fig.3b] is a view of the bicycle, the electric machine is arranged in the hub of the front wheel.

[0022] [Fig.4] is a view of the bicycle, on a stable support.

[0023] [Fig.5] presents the control flowchart of the hybrid bicycle.

[0024] The bicycle 10 shown in [Fig.1] consists of a frame 11, a rear wheel 12a, a front wheel 12b, a crankset 13, a handlebar 14 and a saddle 15.

[0025] At the pedal assembly, the hybrid motor-generator assembly 20 is arranged. Inside a protective casing 21: • an electric generator 22 is in permanent mechanical link 23 with the crankshaft 13 by a succession of sprockets or chains providing an appropriate overdrive ratio; • an electric motor 24 is in permanent mechanical connection with the toothed wheel 25 carried by the hub of the rear wheel 12a and via the toothed chain or belt 26.

[0026] A removable battery 30 for storing electrical energy is carried by a support fixed to the frame 11.

[0027] A controller 100, for example arranged on the frame 11 near the battery 30, is responsible for energy management, motor and generator controls, and whose algorithm reacts to information from the elements of the hybrid assembly 20 and the cyclist.

[0028] Fig. 2 shows the handlebar 14 and the components it carries.

[0029] First, the handlebars carry the lever 141. This lever provides the controller 100 with the cruising speed information 110 (see [Fig. 5]) requested by the cyclist. It is a rotary potentiometer (the speed setting is a linear function of the angle of rotation). It has a return mechanism, and releasing it resets it to the requested zero speed.

[0030] A second rotary lever 142 provides the controller 100 with information on pedaling resistance 114 (see [Fig. 5]), in other words, the level of energy supplied to the battery while riding, as selected by the cyclist. It has several stable angular positions, meaning it remains in position even if released.

[0031] To initiate the roll-on, the cyclist does not need to pedal, but simply to activate lever 141. This is the take-off assistance permitted by regulations up to a low speed, approximately that of walking. Beyond this speed, and to reach the speed setting corresponding to the lever position 141, pedaling is mandatory regardless of the energy recovery setting corresponding to the position of lever 142.

[0032] Since the crankset has no mechanical connection to the wheels 12a, 12b, the pedaling speed is completely independent of the speed of the bicycle 10. To achieve the energy recovery target corresponding to the position of the lever 142, the cyclist can choose between relatively fast pedaling with low to moderate perceived resistance or relatively slow pedaling with moderate to high perceived resistance. Indeed, the power P (in watts), here muscular, is the product of the torque C (in Nm) and the rotational speed W (in rad / s). Power is energy (in Joules) divided by time (in s). For a given power, in other words, energy recovered per second, if W is large then C is small and vice versa.

[0033] In the embodiment shown, the speed control 141 is positioned on the right and the recharge level control 142 on the left. They can be interchanged.

[0034] On each side, at the level of each control lever 141, 142, there is a brake handle 143, 144. Handle 143 preferentially actuates the brake associated with the rear wheel 12a (not shown in all figures). Handle 144 preferentially actuates the brake associated with the front wheel 12b (not shown in the figures).

[0035] Each brake handle is associated with a rotation sensor 145, 146 that indicates the braking intensity. The actuation strokes are divided into two angular sectors. The first sector will trigger the electric brake proportionally to the activation angle, the second the mechanical brake with the electric braking at the maximum level.

[0036] Activation of one of the brake handles 143, 144 inhibits the setting of the lever 141, since the electric motor 24 becomes a generator and performs kinetic energy recovery.

[0037] The handlebar 14 supports a simple control panel 147. It includes the ignition key housing 147a, a first button 147b informing the controller of an upcoming riding session, and a second button 147c informing the controller 100 of an upcoming exercise session. This is the key advantage of this hybrid concept: a bicycle for both transportation and exercise, due to the connection of the crankset to a generator and without disconnecting either of the wheels.

[0038] The handlebar 14 also serves as a support for a display 148 for communication with the controller. Multiple information can be displayed, including, among other things, information for the riding phase: • bicycle speed; • instantaneous pedaling power; • battery charge percentage; • continuously, the battery's charging or discharging status; • an estimate of the possible distance to be covered (incentive to pedal if very low); •

[0039] [Fig.3a] and [Fig.3b] are variant embodiments of hybrid bicycle 10.

[0040] In [Fig. 3a], the electric motor is relocated to the rear wheel hub 12a. This is a known and available arrangement. The hybrid assembly 20, comprising the crankset 13, the generator 22, and the mechanical linkage 23, remains unchanged. Only the protective casing 21 is redesigned.

[0041] In [Fig. 3b], the electric motor is relocated to the hub of the front wheel 12b. This is also a known design arrangement. This arrangement is less advantageous for traction due to the load shift to the rear wheel, but conversely, more advantageous for braking power for the same reason. It has been observed that the braking power from the front wheel is greater without wheel lockup, whereas this is a tendency for the rear wheel.

[0042] [Fig. 4] shows the bicycle 10 set up for a physical exercise session. For this purpose, the bicycle is held in a stable vertical position by the support 50. By pressing the exercise button 147c, the electric motor 24 is deactivated, and the screen displays the exercise parameters: • instantaneous pedaling speed; • instantaneous power; • duration of the current physical exercise; • energy in calories expended; •

[0043] Fig. 5 shows a flowchart of the input and output information of a controller 100. The steering of the bicycle (apart from the trajectory by the handlebars) is done via information provided to the controller in a manner comparable to that provided by the pedals on an automobile.

[0044] The incoming information is: • In order to take into account the requested speed setting, the controller needs to know the actual speed of the bicycle. The electric motor 24, which is the sole power source for the bicycle, is a permanent magnet synchronous type. Its control is achieved via a resolver that provides its rotational speed. Since it is in permanent mechanical contact, the motor's rotational speed information provided to the controller allows the bicycle's speed to be deduced. • The pedaling speed 111. The crankset 13 is in permanent mechanical connection with the generator 22. It is also a permanent magnet synchronous type. Its control is achieved via a resolver which provides its rotational speed. The multiplication ratio of the mechanical connection 23 is constant, and therefore the generator rotational speed information provided to the controller 100 allows the pedaling speed 111 to be deduced. • the battery charge level 112; • the requested cruising speed position 113 on the 141 lever; • the level of pedaling resistance 114 given by the position of the lever 142; • the incline of the path given by a slope 115 incline sensor. This sensor can be integrated into the controller; • the presence of the ignition key 116 provided by a dedicated switch; • the braking level 117, for electric braking alone or for combined mechanical and electric braking by one of the rotation sensors 145,146 of the brake handles 143,144; • Activation of the rolling button 118; • Activation of the physical exercise button 119.

[0045] The outgoing and therefore control information is: • the control 120 of the electric motor 24 in both driving and braking function; • Generator control 121 at recovery power level: • Display control on screen 148: • bicycle speed; • the instantaneous pedaling power; • the percentage of remaining battery charge; • continuously, the battery charging or discharging status; • an estimate of the possible distance to be covered (incentive to cycle if low); • the instantaneous pedaling speed during physical exercise; • instantaneous power during physical exercise; • the duration of the physical exercise in progress; • energy in calories expended.

[0046] Below are some details relating to the operation of the hybrid bicycle 10.

[0047] The presence of the ignition key 116 causes the controller 100 and of screen 148.

[0048] Next, you must activate either the rolling button 147b or the physical exercise button 147c.

[0049] Rolling requires the activation of lever 141.

[0050] Pedaling is mandatory to reach the speed requested by the lever 141, and simultaneously, the pedaling resistance setting given by the lever 142 can remain at level 0.

[0051] In the event of a downward slope, the electric motor 24 switches to electric brake mode if the speed reaches or exceeds the speed setpoint given by the lever 141. Simultaneously, pedaling can be interrupted.

[0052] In the event of a depleted battery, the vehicle can still be driven using only muscle power. All the power supplied to the electric motor 24 comes from the generator 22. The speed setting can only be reached if it is consistent with the pedal resistance setting (muscle power developed at least equal to the motor's requirement).

Claims

Demands

1. Hybrid bicycle (10) comprising: a frame (11), rear (12a) and front (12b) wheels, a crankset (13), handlebars (14) carrying control levers (141, 142) and brake levers (143, 144) each equipped with a rotation sensor (145, 146), a control panel (147), a display (148), a saddle (15), a hybrid motor-generator unit (20) consisting of an electric generator (22) and an electric motor (24), a removable battery (30) for storing electrical energy carried by a bracket fixed to the frame (11), a controller (100) arranged on the frame (11) near the battery responsible for energy management, characterized in that: • the electric generator (22) is in permanent mechanical connection (23) with the crankset shaft (13) by a succession of sprockets or chains providing an adequate overdrive ratio; • the electric motor (24) is in permanent mechanical connection with one of the wheels (12a, 12b);• the crankset (13) has no mechanical link with either of the wheels (12a,12b).;

2. Hybrid bicycle (10) according to claim 1 characterized in that the electric motor (24) is either arranged near the crankset (13), driving a toothed wheel (25) carried by the hub of the rear wheel (12a) and via a chain or toothed belt (26), or arranged on the hub of the rear wheel (12a), or arranged on the hub of the front wheel (12b).

3. Hybrid bicycle (10) according to claim 1 characterized in that one of the control levers (141), carried by the handlebar (14) is dedicated to providing the controller with the speed command (110) requested by the cyclist, is rotary of the potentiometer type and has a return device which in case of release repositions it on zero speed requested.

4. Hybrid bicycle (10) according to claim 1 characterized in that one of the charging control levers (142) carried by the handlebars (14) is rotary (142) and provides the controller (100) with information on pedaling resistance (114), in other words the level of energy supplied to the battery while riding selected by the cyclist, and has several stable angular positions, that is to say, it maintains its position if it is released.

5. Hybrid bicycle (10) according to claim 1 characterized in that at the level of each control lever (141,142) is arranged a brake handle (143,144) equipped with a rotation sensor (145,146) indicating to the controller the intensity of braking, and the actuation strokes of the two levers being divided into two angular sectors, the first sector triggers the electric brake and this in proportion to the angle of activation, the second sector triggers the mechanical brake with an electric braking at the maximum level.

6. Hybrid bicycle (10) according to claims 3 and 5 characterized in that the activation of one of the brake handles (143,144) inhibits the setting of the speed setpoint control lever (141), and the electric motor (24) becomes a generator and performs kinetic energy recovery.

7. Hybrid bicycle (10) according to claim 1 characterized in that the handlebar (14) is the support of the simple control panel (147) which includes a receptacle (147a) for an ignition key, a first button (147b) informing the controller (100) of an upcoming riding episode, and a second button (147c) informing the controller (100) of an upcoming exercise episode.

8. Hybrid bicycle (10) according to claim 1 or 7 characterized in that, held by a support (50), said bicycle (10) forms with said support (50) a stable assembly usable for a physical exercise session without movement due to the connection of the crankset (13) to the generator (22) without mechanical link with the wheels (12a, 12b).

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