33 results about "Harmonic reduction" patented technology

The invention relates to the technical field of motor control, in particular to a harmonic gear motor based on double encoders and a control method thereof, which comprises the following steps: processing linear Hall element signals output by a rotor shaft encoder, including high-frequency noise suppression, direct-current bias calibration, amplitude normalization and phase difference calibration, to obtain accurate orthogonal signals; a double-dq rotating coordinate system phase-locked loop algorithm is adopted, the calibrated orthogonal signals are processed, and the high-precision real-time angle of the motor rotor is obtained through calculation; based on a signal of an output shaft encoder, matching with a preset angle partition of the harmonic reducer, and identifying an absolute position sector where the current output shaft is located; the rotor angle and the sector angle of the output shaft are fused to generate a high-resolution absolute angle of the output shaft; and based on the fused angle information, a magnetic field orientation control algorithm is adopted to drive a motor, and closed-loop control is achieved.

The present invention provides a harmonic reduction mechanism, a harmonic speed reducer, and a robot, wherein the harmonic reduction mechanism includes a flexspline, a rigid pulley, and a wave generator, wherein the flexspline is sleeved on the wave generator, and the rigid pulley is sleeved on the flexspline and meshes with the flexspline; the reduction ratio of the harmonic reduction mechanism is i, the maximum deformation of the wave generator is ω0, and the modulus of the flexspline is m; wherein a*i+b≤ω0 / m≤a*i+c, a∈[0.002,0.004], b∈[0.6,0.7], c∈[0.8,1], and ω0 and m are both in millimeters; when ω0<m, the flexspline and the rigid pulley mesh without backlash; and when ω0>m, the flexspline and the rigid pulley mesh without interference. According to the technical solution of the present invention, it can be ensured that under different reduction ratios, the flexspline has both good meshing quality and is not easily damaged.

A packaged transistor device includes an RF signal input lead, an RF signal output lead, and a discrete transistor having a transistor structure arranged and / or formed on a substrate. The packaged transistor device also includes at least one harmonic reduction circuit arranged and / or formed on the substrate of the discrete transistor.

The present application provides a real-time optimization method, system and device for inverter output voltage harmonics, the method comprising: obtaining control parameters of an inverter; controlling the inverter to work according to the control parameters and obtaining N waveforms corresponding to N periods; decomposing the N waveforms to determine a to-be-processed waveform harmonic; when the amplitude of the to-be-processed waveform harmonic exceeds a harmonic threshold, a first optimization mode is used for optimization processing; when the amplitude of the to-be-processed waveform harmonic does not exceed the harmonic threshold, a second optimization mode is used for optimization processing. A method combining two harmonic reduction technologies is used, when the harmonic amplitude is small, the active filter function of the auxiliary inverter is used to reduce the harmonic, and the SHEPWM complex calculation is not used, when the harmonic amplitude is large, the SHEPWM technology is used to eliminate the harmonic, and the flexibility of inverter control is improved.

The present invention provides a harmonic reduce control system for controlling an inverter, including a phase-locked loop controller, a voltage sum loop controller, a repetitive controller, a current loop controller, and a harmonic obtaining module. The harmonic obtaining module detects a harmonic value of a load current. The control system generates an inverter current reference value based on a first current value output by the voltage sum loop controller and the harmonic value, calculates a real-time frequency value based on a voltage of the power grid, obtains, through calculation, a repetitive controller output value based on the inverter current reference value, the inverter output current, and the real-time frequency value, and outputs a first duty cycle based on the repetitive controller output value. The control system limits the inverter output current based on the first duty cycle.

The invention provides a harmonic reducer, and belongs to the field of reducers, the harmonic reducer specifically comprises a harmonic speed reduction structure and a planetary speed reduction structure, the harmonic speed reduction structure comprises a middle wheel, a flexible gear and a rigid output gear, the middle wheel can rotate after being subjected to acting force, and a second permanent magnet is arranged on the middle wheel; the first permanent magnet is arranged on the inner circumferential surface of the flexible gear and repels the second permanent magnet, when the middle gear rotates, the flexible gear rotates through the repulsive force between the first permanent magnet and the second permanent magnet, and the rigid output gear is meshed with the flexible gear; compared with the prior art, the first permanent magnet is arranged on the flexible gear, meanwhile, the second permanent magnet is arranged on the middle gear, and in the rotating process of the middle gear, the flexible gear is promoted to rotate through the mutual repelling acting force between the first permanent magnet and the second permanent magnet; in the process, the middle gear and the flexible gear are in flexible transmission, abrasion can be reduced, frequent replacement of the flexible gear is avoided, and the service life is prolonged.

The invention belongs to the technical field of rotating platforms, and particularly relates to a hollow rotating platform based on harmonic drive. The hollow rotating platform comprises a driving mechanism, a rear end cover, a wire passing sleeve, a front end cover, a first oil seal, a second oil seal and a harmonic speed reducing mechanism, the harmonic speed reducing mechanism is arranged in the sealing cavity and sleeves the wire passing sleeve, the input end of the harmonic speed reducing mechanism is in transmission connection with the rotating end, and the output end of the harmonic speed reducing mechanism is in transmission connection with the front end cover; and the front end cover is driven to rotate around the axis of the wire sleeve. Compared with the prior art, on the premise that the friction damping borne by the second oil seal is not changed, the first oil seal is located between the wire passing sleeve and the front end cover, and after speed reduction is conducted through the harmonic speed reduction mechanism, the rotating speed of the front end cover is reduced, so that the friction damping of the first oil seal is reduced, and the torque of the driving mechanism can be amplified by dozens of times after speed reduction is conducted through the harmonic speed reduction mechanism; therefore, the operation efficiency of the hollow rotating platform can be further improved, and the energy consumption of the driving mechanism is reduced.

The invention relates to a harmonic speed reduction joint motor module integrated with a torque sensor, which comprises a motor assembly, a controller assembly and a harmonic speed reducer, and is characterized in that the controller assembly comprises a controller buckle cover and a circuit board A, the controller buckle cover is fixed with one end of a shell, a mounting cavity is formed between the controller buckle cover and the shell, and the circuit board A is fixed in the mounting cavity; a wiring terminal is arranged on the circuit board A, a wire passing hole is formed in the controller buckle cover, a power supply and signal wire harness is connected with the wiring terminal through the wire passing hole, and a wiring cover is further fixed on the wire passing hole; the harmonic reducer comprises a wave generator, a flexible gear, a steel wheel, a bearing inner ring and a bearing outer ring, an output disc is further fixed to the bearing outer ring, and a torque sensor is further fixed to the output disc; the rigid requirements of high-precision robot joints for compactness, reliability and dynamic response performance are met, and meanwhile line connection operation of the structure is more convenient.

A packaged transistor device includes an RF signal input lead, an RF signal output lead, and a discrete transistor having a transistor structure arranged and / or formed on a substrate. The packaged transistor device also includes at least one harmonic reduction circuit arranged and / or formed on the substrate of the discrete transistor.

This invention discloses a dual-motor harmonic reduction geared workbench, relating to the technical field of harmonic reduction transmission equipment. It includes a base and an outer motor housing. The top surface of the base is fixedly mounted to the outer motor housing. An upper housing is mounted on the top surface of the outer motor housing, and an output flange is rotatably mounted on the upper housing. A first driving component is installed inside the outer motor housing. A second driving component is installed inside both the outer motor housing and the upper housing. An output internal gear ring is rotatably mounted inside the upper housing, with its top surface fixedly mounted to the output flange. A flexible wheel is disposed inside both the outer motor housing and the upper housing. Through the coordinated operation of the two motors, high-speed rotation of the output flange can be achieved. Furthermore, through the independent operation of the second driving component, low-speed, high-torque output can be achieved based on the harmonic low-tooth-difference transmission principle. This allows the same equipment to be compatible with both high-speed light-load and low-speed heavy-load operating conditions, meeting the production needs of alternating complex on-site operations.

The invention relates to a motor driving device and an air conditioner having the same. A motor driving device according to an embodiment of the present invention comprises: a rectifying unit that rectifies a three-phase AC voltage; a capacitor for storing the pulsating voltage from the rectifying unit; a first voltage detection unit that detects the ripple voltage stored in the capacitor; a harmonic reduction unit that is disposed between the rectification unit and the capacitor, has at least one switching element and a second capacitor, and performs harmonic reduction of the three-phase AC voltage; a current detection unit that detects a current flowing in the harmonic reduction unit; a second voltage detection unit that detects a voltage across the second capacitor in the harmonic reduction unit; an inverter having a plurality of switching elements and outputting the converted AC voltage to the motor using the voltage across the capacitor; and a control unit that controls the harmonic reduction unit on the basis of the pulsating voltage from the first voltage detection unit, the detected current from the current detection unit, and the detected voltage from the second voltage detection unit.

The present invention concerns a harmonic wave reduction and bearing assembly (10, 10'; 11, 11'), comprising a housing (26) housing an input side bearing (12, 12'), a harmonic wave reduction stage (30, 30') and an output side bearing (14, 14') that are aligned on a common central axis (22), wherein the harmonic wave reduction stage (30, 30') is sandwiched between the input side bearing (12, 12') and the output side bearing (14, 14'), wherein the input side bearing (12, 12') and the output side bearing (14, 14') are each of the radial or the radiaxial bearing type and have a plurality of rolling elements (16) positioned between a radially outer bearing ring (20, 20') and a radially inner bearing ring (18, 18'), wherein the reduction stage (30, 30') comprises, in a radial direction, an inner reduction stage ring (32), a central reduction stage ring (34) and an outer reduction stage ring (36) that are concentric with each other and configured to cooperate to perform the harmonic wave-type reduction action, wherein the inner reduction stage ring (32) is configured to rotate with the inner bearing ring (18) of the input side bearing (12, 12'), the central reduction stage ring (34) is configured to rotate with the inner bearing ring (18') of the output side bearing (14, 14') and the outer reduction stage ring (36) is configured to be coupled to the outer bearing rings (20, 20') of both the input side bearing (12, 12') and the output side bearing (14, 14').

This invention discloses an intelligent force-controlled joint module, comprising: a power component; a harmonic reduction output component, the harmonic reduction output component including a harmonic reducer, the harmonic reducer being mounted on the power component and connected to the motor shaft of the power component for transmission, thereby reducing the rotational power transmitted from the power component, increasing the torque, and then outputting it to perform work; a torque sensing component, the torque sensing component including an embedded torque sensor, the embedded torque sensor being simultaneously mounted on the power component and the harmonic reduction output component, for detecting and sensing the external load connected to the output end of the harmonic reducer; and a detection control component, the detection control component including a speed detection component and a control component, the speed detection component being mounted on the power component, simultaneously detecting the high speed of the motor shaft and the low speed of the output end of the harmonic reduction output component. This invention features a reasonable structural design, high integration, compact structure, small overall size, convenient installation, and simple use.

The utility model provides a harmonic speed reducer and a mechanical arm joint device, and the harmonic speed reducer comprises a driving unit, a wave generator, a needle bearing part, an elastic gear part and a rigid part. The wave generator has an inner circular hole portion and an outer contour portion. The driving unit is arranged in the inner circular hole part to drive the wave generator to rotate. The section of the outer contour part is in a cam shape or an oval shape. The needle bearing piece is arranged on the outer contour part. The elastic gear piece is provided with an inner circle containing part and an outer tooth part. The wave generator is arranged in the inner circle containing part, and the needle bearing piece makes contact with the surface of the inner circle containing part. The rigid piece is provided with a rigid containing part. The rigid accommodating part accommodates the elastic gear piece. And an inner tooth part is arranged on the surface of the rigid accommodating part. When the wave generator drives the elastic gear piece to rotate, the outer gear part is meshed with the inner gear part to generate relative rotation.

The utility model discloses a short-tube harmonic speed reduction module for an intelligent robot with a body, which comprises a motor casing, a harmonic speed reduction module, a harmonic speed reduction module and a harmonic speed reduction module, and is characterized in that a motor component is arranged in the motor casing; a mounting groove is formed in the transverse right end surface of the motor shell; the casing end cover is fixed at the transverse left end of the motor casing, the center of the casing end cover protrudes outwards to form a section of step, and the outer edge of the step is a bearing interface which is used for being connected with external equipment; the left side of an end cover of the brake assembly is fixedly connected with the motor shell through a mounting groove; the right side of the end cover of the brake assembly extends into the cavity of the harmonic reducer flexible gear; the double encoders are arranged between the rotor part of the motor assembly and the left end face of the motor shell; wherein the motor assembly, the brake assembly and the harmonic reducer are sleeved on a shaft of the flange; the steel wheel end face of the harmonic reducer is fixedly connected with a flange plate of the flange. The motor casing extends axially to form a mounting cavity, and the driver assembly is mounted in the mounting cavity.

The invention discloses a frequency conversion device and a harmonic suppression control method thereof, and the frequency conversion device comprises a commutation circuit of which the input end is used for accessing a power grid and the output end is used for accessing a load, and is used for converting the alternating current of the power grid into frequency-adjustable alternating current to be provided for the load to use; the variable inductance module is connected between the input end of the commutation circuit and a power grid and is used for generating different inductance values; the input end of the sampling control circuit is connected to a loop between the output end of the commutation circuit and the load, and the output end of the sampling control circuit is connected with the variable inductance module; and the variable inductance module is controlled to generate a corresponding inductance value according to the collected current and voltage, and the inductance value is input to a loop between the input end of the converter circuit and a power grid. The frequency conversion device can effectively restrain multiple dynamic harmonics generated by the device, and harmonic pollution of a power grid is reduced.

The invention relates to a motor driving device and an air conditioner having the same. A motor driving device according to an embodiment of the present invention comprises: a rectifying unit that rectifies a three-phase AC voltage; a capacitor for storing the pulsating voltage from the rectifying unit; a harmonic reduction unit that is disposed between the rectification unit and the capacitor, has at least one switching element, and performs harmonic reduction of the three-phase AC voltage; and an inverter having a plurality of switching elements and outputting the converted AC voltage to the motor using the voltage across the capacitor. The harmonic reduction unit is turned on or off on the basis of the output power of the inverter. Consequently, harmonics of the input current based on the three-phase AC voltage can be reduced.

The present invention provides a high-precision multi-stage servo reducer, belonging to the technical field of reducers. This high-precision multi-stage servo reducer includes a harmonic reduction structure, a gear reduction structure, and a servo housing structure; the harmonic reduction structure mainly includes a fixed rigid gear, a driven flexible gear, and a wave generator nested and installed in sequence, and the gear reduction structure mainly includes a driving gear, a first-stage reduction gear, and a second-stage reduction gear; the fixed rigid gear and the driven flexible gear are meshed and connected to each other, and the wave generator is fitted and installed with fastening bolts on both sides and the top of the cylinder long axis and is closely fitted with the driven flexible gear, and is connected with the second-stage reduction gear at the bottom. The driving gear is sleeved on the working shaft of the DC motor, and the DC motor is regulated by the control circuit board. When running, it drives the driving gear, the first-stage reduction gear, the second-stage reduction gear, and the wave generator step by step in sequence. The present invention has the advantages of high transmission ratio, high transmission precision, strong load-bearing capacity, stable transmission, strong practicability, and long service life.

The utility model discloses a kind of split wave generator harmonic reducer devices, comprising: mandrel, the radial of the mandrel has protruding installation part, the first guide rail slot is on the installation part;Input shaft, the input shaft clearance sleeve is set outside mandrel, the end surface of the input shaft has second guide rail slot;Cross slider, the first slider and second slider are on the cross slider, the cross slider is sleeved on mandrel, and first slider is loaded into first guide rail slot, and second slider is loaded into second guide rail slot;The input shaft is provided with screw hole along radial, screw is screwed into the screw hole, and the end surface of screw and cross slider is contacted to fasten cross slider.Harmonic reducer device includes the split wave generator described above, the outer ring of the input shaft is connected with the bearing of harmonic reducer the utility model split wave generator and harmonic reduction device, can be separately more worn cross slider or mandrel, without overall disassembly, reduce maintenance cost, can better transmission movement and power, simultaneously can also reduce wear and tear and improve accuracy.

The utility model belongs to the technical field of electroacoustics, and particularly relates to a quarter-wavelength wave trap structure suitable for earphone sound conduits, which aims to eliminate unnecessary harmonic waves and coupling peaks, is arranged on a main sound conduit of a sound production unit and comprises a plurality of branch sound conduits. One end of the main sound conduit is communicated with the sound production unit; one end of the branch sound conduit is communicated with the main sound conduit. The utility model has the advantages that the sound quality of the earphone is obviously improved, and excellent harmonic reduction and coupling peak suppression effects are provided.

The utility model relates to a harmonic speed reduction joint motor module integrated with a torque sensor, comprising a motor assembly, a controller assembly and a harmonic speed reducer, the controller assembly comprises a controller buckle cover and a circuit board A, the controller buckle cover is fixed with one end of a housing, an installation cavity is formed between the controller buckle cover and the housing, the circuit board A is fixed in the installation cavity, and the circuit board A is fixed in the housing. A wiring terminal is arranged on the circuit board A, a wire passing hole is formed in the controller buckle cover, a power supply and signal wire harness is connected with the wiring terminal through the wire passing hole, and a wiring cover is further fixed on the wire passing hole; the harmonic reducer comprises a wave generator, a flexible gear, a steel wheel, a bearing inner ring and a bearing outer ring, an output disc is further fixed to the bearing outer ring, and a torque sensor is further fixed to the output disc; the high-precision robot joint meets the strict requirements of compactness, reliability and dynamic response performance of the high-precision robot joint, and meanwhile line connection operation of the high-precision robot joint is more convenient.

The present invention discloses a stator and a permanent magnet synchronous servo motor, belonging to the technical field of motors, to solve the problem that the coupling effect of the controller harmonics generates high-order harmonics and low-order harmonics, making the magnetic field of the motor uneven, increasing the torque ripple of the motor, generating relatively large electromagnetic noise, and also increasing the losses of the motor. A stator of the present invention is provided with U, V, and W three-phase windings on the stator, and a harmonic reduction circuit is connected to the input ends of the three-phase windings. The harmonic reduction circuit is used to filter out high-order and low-order harmonics during the operation of the motor. By connecting a harmonic reduction circuit to the connection ends of the three-phase windings of the motor, the high-order and low-order harmonics at the output end of the controller can be filtered out, so that the magnetic field of the motor is not affected by the harmonics, the uniformity of the motor magnetic field can be improved, the magnetic field roundness can be improved, the harmonic losses of the motor can be reduced, the efficiency of the motor can be improved, and the electromagnetic noise of the motor can be reduced.

A packaged transistor device includes an RF signal input lead, an RF signal output lead, and a discrete transistor having a transistor structure arranged and / or formed on a substrate. The packaged transistor device also includes at least one harmonic reduction circuit arranged and / or formed on the substrate of the discrete transistor.

The present invention concerns a harmonic wave reduction and bear- ing assembly and an electric motor arrangement. The assembly comprises an input side radial or radiaxial bearing and an output side radial or radiaxial bearing in axial alignment with the input side bearing, the input side bearing and the output side bearing each having a plurality of rolling elements positioned between an outer bearing ring and an inner bearing ring, the assembly further comprising a har- monic wave reduction stage located axially in between the input side bearing and the output side bearing, the reduction stage being configured to perform a wave-type reduction action and having an inner reduction stage ring, a central reduction stage ring and an outer reduction stage ring that are concentric with each other as well as with the input side bearing and the output side bearing, wherein the inner reduction stage ring is configured to rotate with the inner ring of the input side bearing, the central reduction stage ring is configured to rotate with the inner ring of the output side bearing and the outer - 24 - reduction stage ring is configured to be coupled to the outer rings of both the input side bearing and the output side bearing.

In an example, an amplifier is provided. The comprises a first pair of transistors comprising a first transistor and a second transistor. The amplifier also comprises a first trace connected to a drain of the first transistor, and a second trace connected to a drain of the second transistor. The amplifier also comprises a harmonic reduction first circuit comprising a harmonic reduction first subcircuit and a harmonic reduction second subcircuit. The harmonic reduction first subcircuit comprises a first inductor and a first capacitor. The first inductor and the first capacitor are connected between a first node and a first reference voltage. The harmonic reduction first subcircuit also comprises a second inductor. The second inductor and one of the first capacitor and a second capacitor are connected between a second node and the first reference voltage. The harmonic reduction second subcircuit comprises a third inductor and a third capacitor. The third inductor and the third capacitor are connected between the first node and the first reference voltage. The harmonic reduction second subcircuit also comprises a fourth inductor. The fourth inductor and one of the third capacitor and a fourth capacitor are connected between the second node and the first reference voltage. The amplifier further comprises a third trace connected to the first node. At least part of the third trace is adjacent and substantially parallel to a first at least part of the first trace. The amplifier further comprises a fourth trace connected to the second node. At least part of the fourth trace is adjacent and substantially parallel to a first at least part of the second trace.

The utility model belongs to the technical field of universal harmonic speed-reducing joint modules of robots, and particularly relates to a universal harmonic speed-reducing joint module of a robot, which comprises a harmonic speed-reducing joint module body, and the front end of the harmonic speed-reducing joint module body is connected with a connecting flange. An oil injection hole is formed in the top end of a shell of the harmonic speed reduction joint module body, an annular supporting block is mounted in the oil injection hole, a filter screen is connected to the top end of the annular supporting block, a mounting block is connected to the top end of the filter screen, and a bolt is connected to the top end of the mounting block in a penetrating and threaded mode. According to the utility model, the filter screen is assembled in the oil injection hole, so that the problem that impurities are carried when lubricating oil is directly added is effectively reduced, and the filter screen is used for filtering, so that the cleanliness and the lubricating effect of the lubricating oil are ensured, and the abrasion degree and the fault occurrence rate of parts are obviously reduced. And the service life of the harmonic speed reduction joint module body is further prolonged.

The present application discloses a harmonic reduction device, which includes a wave generator, a flexspline, a first rigid gear and a second rigid gear. The wave generator can be driven to rotate about the central axis. The periphery of the flexspline has a plurality of first external tooth-like structures, separation grooves and a plurality of second external tooth-like structures. The first rigid gear includes a plurality of first internal tooth-like structures for meshing with the plurality of first external tooth-like structures. The second rigid gear includes a plurality of second internal tooth-like structures for meshing with the plurality of second external tooth-like structures. The included angle between the first intersection line of the first top surface and the cross-section of each first internal tooth-like structure and the first horizontal line is between 0.1 and 5 degrees. The distance between the first intersection line and the central axis in the cross-section gradually decreases from the inner side to the outer side of the first rigid gear. The normal line of the cross-section is perpendicular to the central axis, and the central axis passes through the cross-section.

The invention discloses an encapsulation sealing harmonic gear motor, which relates to the technical field of motors and comprises a rotor shaft, a stator group, a harmonic reducer and a casing. A cavity is formed in the machine shell, one side of the cavity is provided with an end face with a through hole formed in the center, the other side of the cavity is provided with an opening, and the rotor shaft, the stator set and the harmonic reducer are coaxially arranged in the cavity of the machine shell. The stator group is embedded and fixed on one side, provided with the end face, of the casing, and the two sides of the end face of the stator group are coated with a potting layer; a penetrating through hole is formed in the center of the stator group, and the rotor shaft coaxially penetrates through the hole of the stator group and can freely rotate; one end of the rotor shaft extends and passes through the end face through hole of the casing, and the other end is in transmission connection with the input end of the harmonic reducer. The input end side of the harmonic reducer abuts against the cavity opening of the machine shell in a sealed mode, and the harmonic reducer and the machine shell jointly define a sealed cavity. According to the potting seal, the volume and the weight of the motor are reduced while the sealing effect of a traditional oil seal structure is achieved.

The application provides a harmonic reducer, a rotary motor, a harmonic joint and a robot. The harmonic reducer comprises a steel wheel, a wave generator, a flexspline and an output encoder. The steel wheel has a first accommodating space. The wave generator is arranged in the first accommodating space and connected with the rotary motor. The flexspline is arranged between the steel wheel and the wave generator, and the flexspline is engaged with the steel wheel. The wave generator is used to drive the flexspline to rotate. The output encoder comprises a code disc and a circuit board. The code disc is arranged on the flexspline, and the circuit board is arranged in a spaced manner with the code disc. In this way, the torque can be increased, the output encoder can be integrated on the flexspline of the harmonic reducer, the volume of the harmonic reducer and the output encoder can be reduced, and miniaturization can be realized.

In an example, an amplifier is provided. The amplifier comprises a first pair of transistors comprising a first transistor and a second transistor. The amplifier also comprises a first trace connected to a drain of the first transistor, and a second trace connected to a drain of the second transistor. The amplifier also comprises a harmonic reduction first circuit comprising at least one first inductor connected between a first node and a second node. The harmonic reduction first circuit further comprises a third trace connected to the first node, wherein at least part of the third trace is adjacent and substantially parallel to a first at least part of the first trace, and a fourth trace connected to the second node, wherein at least part of the fourth trace is adjacent and substantially parallel to a first at least part of the second trace.